diff --git a/packages/MediaComponents/apex/Android.bp b/packages/MediaComponents/apex/Android.bp
new file mode 100644
index 0000000..363a416
--- /dev/null
+++ b/packages/MediaComponents/apex/Android.bp
@@ -0,0 +1,39 @@
+filegroup {
+    name: "media_aidl",
+    srcs: [
+        "java/android/media/**/*.aidl",
+        "java/android/service/**/*.aidl",
+    ],
+    exclude_srcs: [
+        // Exclude these aidls to avoid errors such as
+        // "Refusing to generate code with unstructured parcelables."
+        "java/android/media/MediaDescription.aidl",
+        "java/android/media/MediaMetadata.aidl",
+        "java/android/media/Rating.aidl",
+        "java/android/media/browse/MediaBrowser.aidl",
+        "java/android/media/session/MediaSession.aidl",
+        "java/android/media/session/ParcelableVolumeInfo.aidl",
+        "java/android/media/session/PlaybackState.aidl",
+    ],
+}
+
+java_library {
+    name: "media",
+    installable: true,
+    sdk_version: "current",
+    srcs: [
+        "java/android/media/**/*.java",
+        "java/android/service/**/*.java",
+        ":media_aidl",
+        ":framework-media-annotation-srcs",
+    ],
+    aidl: {
+        local_include_dirs: ["java"],
+        include_dirs: [
+            "frameworks/base/core/java",
+            // for android.graphics.Bitmap
+            // from IMediaBrowserServiceCallback
+            "frameworks/base/graphics/java",
+            ],
+    },
+}
diff --git a/packages/MediaComponents/apex/java/android/media/IRemoteVolumeController.aidl b/packages/MediaComponents/apex/java/android/media/IRemoteVolumeController.aidl
new file mode 100644
index 0000000..e4a4a42
--- /dev/null
+++ b/packages/MediaComponents/apex/java/android/media/IRemoteVolumeController.aidl
@@ -0,0 +1,32 @@
+/*
+ * Copyright (C) 2014 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package android.media;
+
+import android.media.session.ISessionController;
+
+/**
+ * AIDL for the MediaSessionService to report interesting events on remote playback
+ * to a volume control dialog. See also IVolumeController for the AudioService half.
+ * TODO add in better support for multiple remote sessions.
+ * @hide
+ */
+oneway interface IRemoteVolumeController {
+    void remoteVolumeChanged(ISessionController session, int flags);
+    // sets the default session to use with the slider, replaces remoteSliderVisibility
+    // on IVolumeController
+    void updateRemoteController(ISessionController session);
+}
diff --git a/packages/MediaComponents/apex/java/android/media/ISessionTokensListener.aidl b/packages/MediaComponents/apex/java/android/media/ISessionTokensListener.aidl
new file mode 100644
index 0000000..c83a19e
--- /dev/null
+++ b/packages/MediaComponents/apex/java/android/media/ISessionTokensListener.aidl
@@ -0,0 +1,27 @@
+/*
+ * Copyright 2018 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package android.media;
+
+import android.os.Bundle;
+
+/**
+ * Listens for changes to the list of session tokens.
+ * @hide
+ */
+oneway interface ISessionTokensListener {
+    void onSessionTokensChanged(in List<Bundle> tokens);
+}
diff --git a/packages/MediaComponents/apex/java/android/media/MediaDescription.aidl b/packages/MediaComponents/apex/java/android/media/MediaDescription.aidl
new file mode 100644
index 0000000..6f934f7
--- /dev/null
+++ b/packages/MediaComponents/apex/java/android/media/MediaDescription.aidl
@@ -0,0 +1,18 @@
+/* Copyright 2014, The Android Open Source Project
+**
+** Licensed under the Apache License, Version 2.0 (the "License");
+** you may not use this file except in compliance with the License.
+** You may obtain a copy of the License at
+**
+**     http://www.apache.org/licenses/LICENSE-2.0
+**
+** Unless required by applicable law or agreed to in writing, software
+** distributed under the License is distributed on an "AS IS" BASIS,
+** WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+** See the License for the specific language governing permissions and
+** limitations under the License.
+*/
+
+package android.media;
+
+parcelable MediaDescription;
diff --git a/packages/MediaComponents/apex/java/android/media/MediaDescription.java b/packages/MediaComponents/apex/java/android/media/MediaDescription.java
new file mode 100644
index 0000000..e6aea99
--- /dev/null
+++ b/packages/MediaComponents/apex/java/android/media/MediaDescription.java
@@ -0,0 +1,382 @@
+package android.media;
+
+import android.annotation.Nullable;
+import android.graphics.Bitmap;
+import android.media.browse.MediaBrowser;
+import android.net.Uri;
+import android.os.Bundle;
+import android.os.Parcel;
+import android.os.Parcelable;
+
+/**
+ * A simple set of metadata for a media item suitable for display. This can be
+ * created using the Builder or retrieved from existing metadata using
+ * {@link MediaMetadata#getDescription()}.
+ */
+public class MediaDescription implements Parcelable {
+    /**
+     * A unique persistent id for the content or null.
+     */
+    private final String mMediaId;
+    /**
+     * A primary title suitable for display or null.
+     */
+    private final CharSequence mTitle;
+    /**
+     * A subtitle suitable for display or null.
+     */
+    private final CharSequence mSubtitle;
+    /**
+     * A description suitable for display or null.
+     */
+    private final CharSequence mDescription;
+    /**
+     * A bitmap icon suitable for display or null.
+     */
+    private final Bitmap mIcon;
+    /**
+     * A Uri for an icon suitable for display or null.
+     */
+    private final Uri mIconUri;
+    /**
+     * Extras for opaque use by apps/system.
+     */
+    private final Bundle mExtras;
+    /**
+     * A Uri to identify this content.
+     */
+    private final Uri mMediaUri;
+
+    /**
+     * Used as a long extra field to indicate the bluetooth folder type of the media item as
+     * specified in the section 6.10.2.2 of the Bluetooth AVRCP 1.5. This is valid only for
+     * {@link MediaBrowser.MediaItem} with {@link MediaBrowser.MediaItem#FLAG_BROWSABLE}. The value
+     * should be one of the following:
+     * <ul>
+     * <li>{@link #BT_FOLDER_TYPE_MIXED}</li>
+     * <li>{@link #BT_FOLDER_TYPE_TITLES}</li>
+     * <li>{@link #BT_FOLDER_TYPE_ALBUMS}</li>
+     * <li>{@link #BT_FOLDER_TYPE_ARTISTS}</li>
+     * <li>{@link #BT_FOLDER_TYPE_GENRES}</li>
+     * <li>{@link #BT_FOLDER_TYPE_PLAYLISTS}</li>
+     * <li>{@link #BT_FOLDER_TYPE_YEARS}</li>
+     * </ul>
+     *
+     * @see #getExtras()
+     */
+    public static final String EXTRA_BT_FOLDER_TYPE = "android.media.extra.BT_FOLDER_TYPE";
+
+    /**
+     * The type of folder that is unknown or contains media elements of mixed types as specified in
+     * the section 6.10.2.2 of the Bluetooth AVRCP 1.5.
+     */
+    public static final long BT_FOLDER_TYPE_MIXED = 0;
+
+    /**
+     * The type of folder that contains media elements only as specified in the section 6.10.2.2 of
+     * the Bluetooth AVRCP 1.5.
+     */
+    public static final long BT_FOLDER_TYPE_TITLES = 1;
+
+    /**
+     * The type of folder that contains folders categorized by album as specified in the section
+     * 6.10.2.2 of the Bluetooth AVRCP 1.5.
+     */
+    public static final long BT_FOLDER_TYPE_ALBUMS = 2;
+
+    /**
+     * The type of folder that contains folders categorized by artist as specified in the section
+     * 6.10.2.2 of the Bluetooth AVRCP 1.5.
+     */
+    public static final long BT_FOLDER_TYPE_ARTISTS = 3;
+
+    /**
+     * The type of folder that contains folders categorized by genre as specified in the section
+     * 6.10.2.2 of the Bluetooth AVRCP 1.5.
+     */
+    public static final long BT_FOLDER_TYPE_GENRES = 4;
+
+    /**
+     * The type of folder that contains folders categorized by playlist as specified in the section
+     * 6.10.2.2 of the Bluetooth AVRCP 1.5.
+     */
+    public static final long BT_FOLDER_TYPE_PLAYLISTS = 5;
+
+    /**
+     * The type of folder that contains folders categorized by year as specified in the section
+     * 6.10.2.2 of the Bluetooth AVRCP 1.5.
+     */
+    public static final long BT_FOLDER_TYPE_YEARS = 6;
+
+    private MediaDescription(String mediaId, CharSequence title, CharSequence subtitle,
+            CharSequence description, Bitmap icon, Uri iconUri, Bundle extras, Uri mediaUri) {
+        mMediaId = mediaId;
+        mTitle = title;
+        mSubtitle = subtitle;
+        mDescription = description;
+        mIcon = icon;
+        mIconUri = iconUri;
+        mExtras = extras;
+        mMediaUri = mediaUri;
+    }
+
+    private MediaDescription(Parcel in) {
+        mMediaId = in.readString();
+        mTitle = in.readCharSequence();
+        mSubtitle = in.readCharSequence();
+        mDescription = in.readCharSequence();
+        mIcon = in.readParcelable(null);
+        mIconUri = in.readParcelable(null);
+        mExtras = in.readBundle();
+        mMediaUri = in.readParcelable(null);
+    }
+
+    /**
+     * Returns the media id or null. See
+     * {@link MediaMetadata#METADATA_KEY_MEDIA_ID}.
+     */
+    public @Nullable String getMediaId() {
+        return mMediaId;
+    }
+
+    /**
+     * Returns a title suitable for display or null.
+     *
+     * @return A title or null.
+     */
+    public @Nullable CharSequence getTitle() {
+        return mTitle;
+    }
+
+    /**
+     * Returns a subtitle suitable for display or null.
+     *
+     * @return A subtitle or null.
+     */
+    public @Nullable CharSequence getSubtitle() {
+        return mSubtitle;
+    }
+
+    /**
+     * Returns a description suitable for display or null.
+     *
+     * @return A description or null.
+     */
+    public @Nullable CharSequence getDescription() {
+        return mDescription;
+    }
+
+    /**
+     * Returns a bitmap icon suitable for display or null.
+     *
+     * @return An icon or null.
+     */
+    public @Nullable Bitmap getIconBitmap() {
+        return mIcon;
+    }
+
+    /**
+     * Returns a Uri for an icon suitable for display or null.
+     *
+     * @return An icon uri or null.
+     */
+    public @Nullable Uri getIconUri() {
+        return mIconUri;
+    }
+
+    /**
+     * Returns any extras that were added to the description.
+     *
+     * @return A bundle of extras or null.
+     */
+    public @Nullable Bundle getExtras() {
+        return mExtras;
+    }
+
+    /**
+     * Returns a Uri representing this content or null.
+     *
+     * @return A media Uri or null.
+     */
+    public @Nullable Uri getMediaUri() {
+        return mMediaUri;
+    }
+
+    @Override
+    public int describeContents() {
+        return 0;
+    }
+
+    @Override
+    public void writeToParcel(Parcel dest, int flags) {
+        dest.writeString(mMediaId);
+        dest.writeCharSequence(mTitle);
+        dest.writeCharSequence(mSubtitle);
+        dest.writeCharSequence(mDescription);
+        dest.writeParcelable(mIcon, flags);
+        dest.writeParcelable(mIconUri, flags);
+        dest.writeBundle(mExtras);
+        dest.writeParcelable(mMediaUri, flags);
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if (o == null) {
+            return false;
+        }
+
+        if (!(o instanceof MediaDescription)){
+            return false;
+        }
+
+        final MediaDescription d = (MediaDescription) o;
+
+        if (!String.valueOf(mTitle).equals(String.valueOf(d.mTitle))) {
+            return false;
+        }
+
+        if (!String.valueOf(mSubtitle).equals(String.valueOf(d.mSubtitle))) {
+            return false;
+        }
+
+        if (!String.valueOf(mDescription).equals(String.valueOf(d.mDescription))) {
+            return false;
+        }
+
+        return true;
+    }
+
+    @Override
+    public String toString() {
+        return mTitle + ", " + mSubtitle + ", " + mDescription;
+    }
+
+    public static final Parcelable.Creator<MediaDescription> CREATOR =
+            new Parcelable.Creator<MediaDescription>() {
+                @Override
+                public MediaDescription createFromParcel(Parcel in) {
+                    return new MediaDescription(in);
+                }
+
+                @Override
+                public MediaDescription[] newArray(int size) {
+                    return new MediaDescription[size];
+                }
+            };
+
+    /**
+     * Builder for {@link MediaDescription} objects.
+     */
+    public static class Builder {
+        private String mMediaId;
+        private CharSequence mTitle;
+        private CharSequence mSubtitle;
+        private CharSequence mDescription;
+        private Bitmap mIcon;
+        private Uri mIconUri;
+        private Bundle mExtras;
+        private Uri mMediaUri;
+
+        /**
+         * Creates an initially empty builder.
+         */
+        public Builder() {
+        }
+
+        /**
+         * Sets the media id.
+         *
+         * @param mediaId The unique id for the item or null.
+         * @return this
+         */
+        public Builder setMediaId(@Nullable String mediaId) {
+            mMediaId = mediaId;
+            return this;
+        }
+
+        /**
+         * Sets the title.
+         *
+         * @param title A title suitable for display to the user or null.
+         * @return this
+         */
+        public Builder setTitle(@Nullable CharSequence title) {
+            mTitle = title;
+            return this;
+        }
+
+        /**
+         * Sets the subtitle.
+         *
+         * @param subtitle A subtitle suitable for display to the user or null.
+         * @return this
+         */
+        public Builder setSubtitle(@Nullable CharSequence subtitle) {
+            mSubtitle = subtitle;
+            return this;
+        }
+
+        /**
+         * Sets the description.
+         *
+         * @param description A description suitable for display to the user or
+         *            null.
+         * @return this
+         */
+        public Builder setDescription(@Nullable CharSequence description) {
+            mDescription = description;
+            return this;
+        }
+
+        /**
+         * Sets the icon.
+         *
+         * @param icon A {@link Bitmap} icon suitable for display to the user or
+         *            null.
+         * @return this
+         */
+        public Builder setIconBitmap(@Nullable Bitmap icon) {
+            mIcon = icon;
+            return this;
+        }
+
+        /**
+         * Sets the icon uri.
+         *
+         * @param iconUri A {@link Uri} for an icon suitable for display to the
+         *            user or null.
+         * @return this
+         */
+        public Builder setIconUri(@Nullable Uri iconUri) {
+            mIconUri = iconUri;
+            return this;
+        }
+
+        /**
+         * Sets a bundle of extras.
+         *
+         * @param extras The extras to include with this description or null.
+         * @return this
+         */
+        public Builder setExtras(@Nullable Bundle extras) {
+            mExtras = extras;
+            return this;
+        }
+
+        /**
+         * Sets the media uri.
+         *
+         * @param mediaUri The content's {@link Uri} for the item or null.
+         * @return this
+         */
+        public Builder setMediaUri(@Nullable Uri mediaUri) {
+            mMediaUri = mediaUri;
+            return this;
+        }
+
+        public MediaDescription build() {
+            return new MediaDescription(mMediaId, mTitle, mSubtitle, mDescription, mIcon, mIconUri,
+                    mExtras, mMediaUri);
+        }
+    }
+}
diff --git a/packages/MediaComponents/apex/java/android/media/MediaMetadata.aidl b/packages/MediaComponents/apex/java/android/media/MediaMetadata.aidl
new file mode 100644
index 0000000..66ee483
--- /dev/null
+++ b/packages/MediaComponents/apex/java/android/media/MediaMetadata.aidl
@@ -0,0 +1,18 @@
+/* Copyright 2014, The Android Open Source Project
+**
+** Licensed under the Apache License, Version 2.0 (the "License");
+** you may not use this file except in compliance with the License.
+** You may obtain a copy of the License at
+**
+**     http://www.apache.org/licenses/LICENSE-2.0
+**
+** Unless required by applicable law or agreed to in writing, software
+** distributed under the License is distributed on an "AS IS" BASIS,
+** WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+** See the License for the specific language governing permissions and
+** limitations under the License.
+*/
+
+package android.media;
+
+parcelable MediaMetadata;
diff --git a/packages/MediaComponents/apex/java/android/media/MediaMetadata.java b/packages/MediaComponents/apex/java/android/media/MediaMetadata.java
new file mode 100644
index 0000000..2721ad1
--- /dev/null
+++ b/packages/MediaComponents/apex/java/android/media/MediaMetadata.java
@@ -0,0 +1,941 @@
+/*
+ * Copyright (C) 2014 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package android.media;
+
+import android.annotation.NonNull;
+import android.annotation.StringDef;
+import android.annotation.UnsupportedAppUsage;
+import android.content.ContentResolver;
+import android.graphics.Bitmap;
+import android.graphics.BitmapFactory;
+import android.media.browse.MediaBrowser;
+import android.media.session.MediaController;
+import android.net.Uri;
+import android.os.Bundle;
+import android.os.Parcel;
+import android.os.Parcelable;
+import android.text.TextUtils;
+import android.util.ArrayMap;
+import android.util.Log;
+import android.util.SparseArray;
+
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.util.Set;
+import java.util.Objects;
+
+/**
+ * Contains metadata about an item, such as the title, artist, etc.
+ */
+public final class MediaMetadata implements Parcelable {
+    private static final String TAG = "MediaMetadata";
+
+    /**
+     * @hide
+     */
+    @StringDef(prefix = { "METADATA_KEY_" }, value = {
+            METADATA_KEY_TITLE,
+            METADATA_KEY_ARTIST,
+            METADATA_KEY_ALBUM,
+            METADATA_KEY_AUTHOR,
+            METADATA_KEY_WRITER,
+            METADATA_KEY_COMPOSER,
+            METADATA_KEY_COMPILATION,
+            METADATA_KEY_DATE,
+            METADATA_KEY_GENRE,
+            METADATA_KEY_ALBUM_ARTIST,
+            METADATA_KEY_ART_URI,
+            METADATA_KEY_ALBUM_ART_URI,
+            METADATA_KEY_DISPLAY_TITLE,
+            METADATA_KEY_DISPLAY_SUBTITLE,
+            METADATA_KEY_DISPLAY_DESCRIPTION,
+            METADATA_KEY_DISPLAY_ICON_URI,
+            METADATA_KEY_MEDIA_ID,
+            METADATA_KEY_MEDIA_URI,
+    })
+    @Retention(RetentionPolicy.SOURCE)
+    public @interface TextKey {}
+
+    /**
+     * @hide
+     */
+    @StringDef(prefix = { "METADATA_KEY_" }, value = {
+            METADATA_KEY_DURATION,
+            METADATA_KEY_YEAR,
+            METADATA_KEY_TRACK_NUMBER,
+            METADATA_KEY_NUM_TRACKS,
+            METADATA_KEY_DISC_NUMBER,
+            METADATA_KEY_BT_FOLDER_TYPE,
+    })
+    @Retention(RetentionPolicy.SOURCE)
+    public @interface LongKey {}
+
+    /**
+     * @hide
+     */
+    @StringDef(prefix = { "METADATA_KEY_" }, value = {
+            METADATA_KEY_ART,
+            METADATA_KEY_ALBUM_ART,
+            METADATA_KEY_DISPLAY_ICON,
+    })
+    @Retention(RetentionPolicy.SOURCE)
+    public @interface BitmapKey {}
+
+    /**
+     * @hide
+     */
+    @StringDef(prefix = { "METADATA_KEY_" }, value = {
+            METADATA_KEY_USER_RATING,
+            METADATA_KEY_RATING,
+    })
+    @Retention(RetentionPolicy.SOURCE)
+    public @interface RatingKey {}
+
+    /**
+     * The title of the media.
+     */
+    public static final String METADATA_KEY_TITLE = "android.media.metadata.TITLE";
+
+    /**
+     * The artist of the media.
+     */
+    public static final String METADATA_KEY_ARTIST = "android.media.metadata.ARTIST";
+
+    /**
+     * The duration of the media in ms. A negative duration indicates that the
+     * duration is unknown (or infinite).
+     */
+    public static final String METADATA_KEY_DURATION = "android.media.metadata.DURATION";
+
+    /**
+     * The album title for the media.
+     */
+    public static final String METADATA_KEY_ALBUM = "android.media.metadata.ALBUM";
+
+    /**
+     * The author of the media.
+     */
+    public static final String METADATA_KEY_AUTHOR = "android.media.metadata.AUTHOR";
+
+    /**
+     * The writer of the media.
+     */
+    public static final String METADATA_KEY_WRITER = "android.media.metadata.WRITER";
+
+    /**
+     * The composer of the media.
+     */
+    public static final String METADATA_KEY_COMPOSER = "android.media.metadata.COMPOSER";
+
+    /**
+     * The compilation status of the media.
+     */
+    public static final String METADATA_KEY_COMPILATION = "android.media.metadata.COMPILATION";
+
+    /**
+     * The date the media was created or published. The format is unspecified
+     * but RFC 3339 is recommended.
+     */
+    public static final String METADATA_KEY_DATE = "android.media.metadata.DATE";
+
+    /**
+     * The year the media was created or published as a long.
+     */
+    public static final String METADATA_KEY_YEAR = "android.media.metadata.YEAR";
+
+    /**
+     * The genre of the media.
+     */
+    public static final String METADATA_KEY_GENRE = "android.media.metadata.GENRE";
+
+    /**
+     * The track number for the media.
+     */
+    public static final String METADATA_KEY_TRACK_NUMBER = "android.media.metadata.TRACK_NUMBER";
+
+    /**
+     * The number of tracks in the media's original source.
+     */
+    public static final String METADATA_KEY_NUM_TRACKS = "android.media.metadata.NUM_TRACKS";
+
+    /**
+     * The disc number for the media's original source.
+     */
+    public static final String METADATA_KEY_DISC_NUMBER = "android.media.metadata.DISC_NUMBER";
+
+    /**
+     * The artist for the album of the media's original source.
+     */
+    public static final String METADATA_KEY_ALBUM_ARTIST = "android.media.metadata.ALBUM_ARTIST";
+
+    /**
+     * The artwork for the media as a {@link Bitmap}.
+     * <p>
+     * The artwork should be relatively small and may be scaled down by the
+     * system if it is too large. For higher resolution artwork
+     * {@link #METADATA_KEY_ART_URI} should be used instead.
+     */
+    public static final String METADATA_KEY_ART = "android.media.metadata.ART";
+
+    /**
+     * The artwork for the media as a Uri formatted String. The artwork can be
+     * loaded using a combination of {@link ContentResolver#openInputStream} and
+     * {@link BitmapFactory#decodeStream}.
+     * <p>
+     * For the best results, Uris should use the content:// style and support
+     * {@link ContentResolver#EXTRA_SIZE} for retrieving scaled artwork through
+     * {@link ContentResolver#openTypedAssetFileDescriptor(Uri, String, Bundle)}.
+     */
+    public static final String METADATA_KEY_ART_URI = "android.media.metadata.ART_URI";
+
+    /**
+     * The artwork for the album of the media's original source as a
+     * {@link Bitmap}.
+     * <p>
+     * The artwork should be relatively small and may be scaled down by the
+     * system if it is too large. For higher resolution artwork
+     * {@link #METADATA_KEY_ALBUM_ART_URI} should be used instead.
+     */
+    public static final String METADATA_KEY_ALBUM_ART = "android.media.metadata.ALBUM_ART";
+
+    /**
+     * The artwork for the album of the media's original source as a Uri
+     * formatted String. The artwork can be loaded using a combination of
+     * {@link ContentResolver#openInputStream} and
+     * {@link BitmapFactory#decodeStream}.
+     * <p>
+     * For the best results, Uris should use the content:// style and support
+     * {@link ContentResolver#EXTRA_SIZE} for retrieving scaled artwork through
+     * {@link ContentResolver#openTypedAssetFileDescriptor(Uri, String, Bundle)}.
+     */
+    public static final String METADATA_KEY_ALBUM_ART_URI = "android.media.metadata.ALBUM_ART_URI";
+
+    /**
+     * The user's rating for the media.
+     *
+     * @see Rating
+     */
+    public static final String METADATA_KEY_USER_RATING = "android.media.metadata.USER_RATING";
+
+    /**
+     * The overall rating for the media.
+     *
+     * @see Rating
+     */
+    public static final String METADATA_KEY_RATING = "android.media.metadata.RATING";
+
+    /**
+     * A title that is suitable for display to the user. This will generally be
+     * the same as {@link #METADATA_KEY_TITLE} but may differ for some formats.
+     * When displaying media described by this metadata this should be preferred
+     * if present.
+     */
+    public static final String METADATA_KEY_DISPLAY_TITLE = "android.media.metadata.DISPLAY_TITLE";
+
+    /**
+     * A subtitle that is suitable for display to the user. When displaying a
+     * second line for media described by this metadata this should be preferred
+     * to other fields if present.
+     */
+    public static final String METADATA_KEY_DISPLAY_SUBTITLE
+            = "android.media.metadata.DISPLAY_SUBTITLE";
+
+    /**
+     * A description that is suitable for display to the user. When displaying
+     * more information for media described by this metadata this should be
+     * preferred to other fields if present.
+     */
+    public static final String METADATA_KEY_DISPLAY_DESCRIPTION
+            = "android.media.metadata.DISPLAY_DESCRIPTION";
+
+    /**
+     * An icon or thumbnail that is suitable for display to the user. When
+     * displaying an icon for media described by this metadata this should be
+     * preferred to other fields if present. This must be a {@link Bitmap}.
+     * <p>
+     * The icon should be relatively small and may be scaled down by the system
+     * if it is too large. For higher resolution artwork
+     * {@link #METADATA_KEY_DISPLAY_ICON_URI} should be used instead.
+     */
+    public static final String METADATA_KEY_DISPLAY_ICON
+            = "android.media.metadata.DISPLAY_ICON";
+
+    /**
+     * A Uri formatted String for an icon or thumbnail that is suitable for
+     * display to the user. When displaying more information for media described
+     * by this metadata the display description should be preferred to other
+     * fields when present. The icon can be loaded using a combination of
+     * {@link ContentResolver#openInputStream} and
+     * {@link BitmapFactory#decodeStream}.
+     * <p>
+     * For the best results, Uris should use the content:// style and support
+     * {@link ContentResolver#EXTRA_SIZE} for retrieving scaled artwork through
+     * {@link ContentResolver#openTypedAssetFileDescriptor(Uri, String, Bundle)}.
+     */
+    public static final String METADATA_KEY_DISPLAY_ICON_URI
+            = "android.media.metadata.DISPLAY_ICON_URI";
+
+    /**
+     * A String key for identifying the content. This value is specific to the
+     * service providing the content. If used, this should be a persistent
+     * unique key for the underlying content. It may be used with
+     * {@link MediaController.TransportControls#playFromMediaId(String, Bundle)}
+     * to initiate playback when provided by a {@link MediaBrowser} connected to
+     * the same app.
+     */
+    public static final String METADATA_KEY_MEDIA_ID = "android.media.metadata.MEDIA_ID";
+
+    /**
+     * A Uri formatted String representing the content. This value is specific to the
+     * service providing the content. It may be used with
+     * {@link MediaController.TransportControls#playFromUri(Uri, Bundle)}
+     * to initiate playback when provided by a {@link MediaBrowser} connected to
+     * the same app.
+     */
+    public static final String METADATA_KEY_MEDIA_URI = "android.media.metadata.MEDIA_URI";
+
+    /**
+     * The bluetooth folder type of the media specified in the section 6.10.2.2 of the Bluetooth
+     * AVRCP 1.5. It should be one of the following:
+     * <ul>
+     * <li>{@link MediaDescription#BT_FOLDER_TYPE_MIXED}</li>
+     * <li>{@link MediaDescription#BT_FOLDER_TYPE_TITLES}</li>
+     * <li>{@link MediaDescription#BT_FOLDER_TYPE_ALBUMS}</li>
+     * <li>{@link MediaDescription#BT_FOLDER_TYPE_ARTISTS}</li>
+     * <li>{@link MediaDescription#BT_FOLDER_TYPE_GENRES}</li>
+     * <li>{@link MediaDescription#BT_FOLDER_TYPE_PLAYLISTS}</li>
+     * <li>{@link MediaDescription#BT_FOLDER_TYPE_YEARS}</li>
+     * </ul>
+     */
+    public static final String METADATA_KEY_BT_FOLDER_TYPE
+            = "android.media.metadata.BT_FOLDER_TYPE";
+
+    private static final @TextKey String[] PREFERRED_DESCRIPTION_ORDER = {
+            METADATA_KEY_TITLE,
+            METADATA_KEY_ARTIST,
+            METADATA_KEY_ALBUM,
+            METADATA_KEY_ALBUM_ARTIST,
+            METADATA_KEY_WRITER,
+            METADATA_KEY_AUTHOR,
+            METADATA_KEY_COMPOSER
+    };
+
+    private static final @BitmapKey String[] PREFERRED_BITMAP_ORDER = {
+            METADATA_KEY_DISPLAY_ICON,
+            METADATA_KEY_ART,
+            METADATA_KEY_ALBUM_ART
+    };
+
+    private static final @TextKey String[] PREFERRED_URI_ORDER = {
+            METADATA_KEY_DISPLAY_ICON_URI,
+            METADATA_KEY_ART_URI,
+            METADATA_KEY_ALBUM_ART_URI
+    };
+
+    private static final int METADATA_TYPE_INVALID = -1;
+    private static final int METADATA_TYPE_LONG = 0;
+    private static final int METADATA_TYPE_TEXT = 1;
+    private static final int METADATA_TYPE_BITMAP = 2;
+    private static final int METADATA_TYPE_RATING = 3;
+    private static final ArrayMap<String, Integer> METADATA_KEYS_TYPE;
+
+    static {
+        METADATA_KEYS_TYPE = new ArrayMap<String, Integer>();
+        METADATA_KEYS_TYPE.put(METADATA_KEY_TITLE, METADATA_TYPE_TEXT);
+        METADATA_KEYS_TYPE.put(METADATA_KEY_ARTIST, METADATA_TYPE_TEXT);
+        METADATA_KEYS_TYPE.put(METADATA_KEY_DURATION, METADATA_TYPE_LONG);
+        METADATA_KEYS_TYPE.put(METADATA_KEY_ALBUM, METADATA_TYPE_TEXT);
+        METADATA_KEYS_TYPE.put(METADATA_KEY_AUTHOR, METADATA_TYPE_TEXT);
+        METADATA_KEYS_TYPE.put(METADATA_KEY_WRITER, METADATA_TYPE_TEXT);
+        METADATA_KEYS_TYPE.put(METADATA_KEY_COMPOSER, METADATA_TYPE_TEXT);
+        METADATA_KEYS_TYPE.put(METADATA_KEY_COMPILATION, METADATA_TYPE_TEXT);
+        METADATA_KEYS_TYPE.put(METADATA_KEY_DATE, METADATA_TYPE_TEXT);
+        METADATA_KEYS_TYPE.put(METADATA_KEY_YEAR, METADATA_TYPE_LONG);
+        METADATA_KEYS_TYPE.put(METADATA_KEY_GENRE, METADATA_TYPE_TEXT);
+        METADATA_KEYS_TYPE.put(METADATA_KEY_TRACK_NUMBER, METADATA_TYPE_LONG);
+        METADATA_KEYS_TYPE.put(METADATA_KEY_NUM_TRACKS, METADATA_TYPE_LONG);
+        METADATA_KEYS_TYPE.put(METADATA_KEY_DISC_NUMBER, METADATA_TYPE_LONG);
+        METADATA_KEYS_TYPE.put(METADATA_KEY_ALBUM_ARTIST, METADATA_TYPE_TEXT);
+        METADATA_KEYS_TYPE.put(METADATA_KEY_ART, METADATA_TYPE_BITMAP);
+        METADATA_KEYS_TYPE.put(METADATA_KEY_ART_URI, METADATA_TYPE_TEXT);
+        METADATA_KEYS_TYPE.put(METADATA_KEY_ALBUM_ART, METADATA_TYPE_BITMAP);
+        METADATA_KEYS_TYPE.put(METADATA_KEY_ALBUM_ART_URI, METADATA_TYPE_TEXT);
+        METADATA_KEYS_TYPE.put(METADATA_KEY_USER_RATING, METADATA_TYPE_RATING);
+        METADATA_KEYS_TYPE.put(METADATA_KEY_RATING, METADATA_TYPE_RATING);
+        METADATA_KEYS_TYPE.put(METADATA_KEY_DISPLAY_TITLE, METADATA_TYPE_TEXT);
+        METADATA_KEYS_TYPE.put(METADATA_KEY_DISPLAY_SUBTITLE, METADATA_TYPE_TEXT);
+        METADATA_KEYS_TYPE.put(METADATA_KEY_DISPLAY_DESCRIPTION, METADATA_TYPE_TEXT);
+        METADATA_KEYS_TYPE.put(METADATA_KEY_DISPLAY_ICON, METADATA_TYPE_BITMAP);
+        METADATA_KEYS_TYPE.put(METADATA_KEY_DISPLAY_ICON_URI, METADATA_TYPE_TEXT);
+        METADATA_KEYS_TYPE.put(METADATA_KEY_BT_FOLDER_TYPE, METADATA_TYPE_LONG);
+        METADATA_KEYS_TYPE.put(METADATA_KEY_MEDIA_ID, METADATA_TYPE_TEXT);
+        METADATA_KEYS_TYPE.put(METADATA_KEY_MEDIA_URI, METADATA_TYPE_TEXT);
+    }
+
+    private static final SparseArray<String> EDITOR_KEY_MAPPING;
+
+    static {
+        EDITOR_KEY_MAPPING = new SparseArray<String>();
+        EDITOR_KEY_MAPPING.put(MediaMetadataEditor.BITMAP_KEY_ARTWORK, METADATA_KEY_ART);
+        EDITOR_KEY_MAPPING.put(MediaMetadataEditor.RATING_KEY_BY_OTHERS, METADATA_KEY_RATING);
+        EDITOR_KEY_MAPPING.put(MediaMetadataEditor.RATING_KEY_BY_USER, METADATA_KEY_USER_RATING);
+        EDITOR_KEY_MAPPING.put(MediaMetadataRetriever.METADATA_KEY_ALBUM, METADATA_KEY_ALBUM);
+        EDITOR_KEY_MAPPING.put(MediaMetadataRetriever.METADATA_KEY_ALBUMARTIST,
+                METADATA_KEY_ALBUM_ARTIST);
+        EDITOR_KEY_MAPPING.put(MediaMetadataRetriever.METADATA_KEY_ARTIST, METADATA_KEY_ARTIST);
+        EDITOR_KEY_MAPPING.put(MediaMetadataRetriever.METADATA_KEY_AUTHOR, METADATA_KEY_AUTHOR);
+        EDITOR_KEY_MAPPING.put(MediaMetadataRetriever.METADATA_KEY_CD_TRACK_NUMBER,
+                METADATA_KEY_TRACK_NUMBER);
+        EDITOR_KEY_MAPPING.put(MediaMetadataRetriever.METADATA_KEY_COMPOSER, METADATA_KEY_COMPOSER);
+        EDITOR_KEY_MAPPING.put(MediaMetadataRetriever.METADATA_KEY_COMPILATION,
+                METADATA_KEY_COMPILATION);
+        EDITOR_KEY_MAPPING.put(MediaMetadataRetriever.METADATA_KEY_DATE, METADATA_KEY_DATE);
+        EDITOR_KEY_MAPPING.put(MediaMetadataRetriever.METADATA_KEY_DISC_NUMBER,
+                METADATA_KEY_DISC_NUMBER);
+        EDITOR_KEY_MAPPING.put(MediaMetadataRetriever.METADATA_KEY_DURATION, METADATA_KEY_DURATION);
+        EDITOR_KEY_MAPPING.put(MediaMetadataRetriever.METADATA_KEY_GENRE, METADATA_KEY_GENRE);
+        EDITOR_KEY_MAPPING.put(MediaMetadataRetriever.METADATA_KEY_NUM_TRACKS,
+                METADATA_KEY_NUM_TRACKS);
+        EDITOR_KEY_MAPPING.put(MediaMetadataRetriever.METADATA_KEY_TITLE, METADATA_KEY_TITLE);
+        EDITOR_KEY_MAPPING.put(MediaMetadataRetriever.METADATA_KEY_WRITER, METADATA_KEY_WRITER);
+        EDITOR_KEY_MAPPING.put(MediaMetadataRetriever.METADATA_KEY_YEAR, METADATA_KEY_YEAR);
+    }
+
+    private final Bundle mBundle;
+    private MediaDescription mDescription;
+
+    private MediaMetadata(Bundle bundle) {
+        mBundle = new Bundle(bundle);
+    }
+
+    private MediaMetadata(Parcel in) {
+        mBundle = Bundle.setDefusable(in.readBundle(), true);
+    }
+
+    /**
+     * Returns true if the given key is contained in the metadata
+     *
+     * @param key a String key
+     * @return true if the key exists in this metadata, false otherwise
+     */
+    public boolean containsKey(String key) {
+        return mBundle.containsKey(key);
+    }
+
+    /**
+     * Returns the value associated with the given key, or null if no mapping of
+     * the desired type exists for the given key or a null value is explicitly
+     * associated with the key.
+     *
+     * @param key The key the value is stored under
+     * @return a CharSequence value, or null
+     */
+    public CharSequence getText(@TextKey String key) {
+        return mBundle.getCharSequence(key);
+    }
+
+    /**
+     * Returns the text value associated with the given key as a String, or null
+     * if no mapping of the desired type exists for the given key or a null
+     * value is explicitly associated with the key. This is equivalent to
+     * calling {@link #getText getText().toString()} if the value is not null.
+     *
+     * @param key The key the value is stored under
+     * @return a String value, or null
+     */
+    public String getString(@TextKey String key) {
+        CharSequence text = getText(key);
+        if (text != null) {
+            return text.toString();
+        }
+        return null;
+    }
+
+    /**
+     * Returns the value associated with the given key, or 0L if no long exists
+     * for the given key.
+     *
+     * @param key The key the value is stored under
+     * @return a long value
+     */
+    public long getLong(@LongKey String key) {
+        return mBundle.getLong(key, 0);
+    }
+
+    /**
+     * Returns a {@link Rating} for the given key or null if no rating exists
+     * for the given key.
+     *
+     * @param key The key the value is stored under
+     * @return A {@link Rating} or null
+     */
+    public Rating getRating(@RatingKey String key) {
+        Rating rating = null;
+        try {
+            rating = mBundle.getParcelable(key);
+        } catch (Exception e) {
+            // ignore, value was not a bitmap
+            Log.w(TAG, "Failed to retrieve a key as Rating.", e);
+        }
+        return rating;
+    }
+
+    /**
+     * Returns a {@link Bitmap} for the given key or null if no bitmap exists
+     * for the given key.
+     *
+     * @param key The key the value is stored under
+     * @return A {@link Bitmap} or null
+     */
+    public Bitmap getBitmap(@BitmapKey String key) {
+        Bitmap bmp = null;
+        try {
+            bmp = mBundle.getParcelable(key);
+        } catch (Exception e) {
+            // ignore, value was not a bitmap
+            Log.w(TAG, "Failed to retrieve a key as Bitmap.", e);
+        }
+        return bmp;
+    }
+
+    @Override
+    public int describeContents() {
+        return 0;
+    }
+
+    @Override
+    public void writeToParcel(Parcel dest, int flags) {
+        dest.writeBundle(mBundle);
+    }
+
+    /**
+     * Returns the number of fields in this metadata.
+     *
+     * @return The number of fields in the metadata.
+     */
+    public int size() {
+        return mBundle.size();
+    }
+
+    /**
+     * Returns a Set containing the Strings used as keys in this metadata.
+     *
+     * @return a Set of String keys
+     */
+    public Set<String> keySet() {
+        return mBundle.keySet();
+    }
+
+    /**
+     * Returns a simple description of this metadata for display purposes.
+     *
+     * @return A simple description of this metadata.
+     */
+    public @NonNull MediaDescription getDescription() {
+        if (mDescription != null) {
+            return mDescription;
+        }
+
+        String mediaId = getString(METADATA_KEY_MEDIA_ID);
+
+        CharSequence[] text = new CharSequence[3];
+        Bitmap icon = null;
+        Uri iconUri = null;
+
+        // First handle the case where display data is set already
+        CharSequence displayText = getText(METADATA_KEY_DISPLAY_TITLE);
+        if (!TextUtils.isEmpty(displayText)) {
+            // If they have a display title use only display data, otherwise use
+            // our best bets
+            text[0] = displayText;
+            text[1] = getText(METADATA_KEY_DISPLAY_SUBTITLE);
+            text[2] = getText(METADATA_KEY_DISPLAY_DESCRIPTION);
+        } else {
+            // Use whatever fields we can
+            int textIndex = 0;
+            int keyIndex = 0;
+            while (textIndex < text.length && keyIndex < PREFERRED_DESCRIPTION_ORDER.length) {
+                CharSequence next = getText(PREFERRED_DESCRIPTION_ORDER[keyIndex++]);
+                if (!TextUtils.isEmpty(next)) {
+                    // Fill in the next empty bit of text
+                    text[textIndex++] = next;
+                }
+            }
+        }
+
+        // Get the best art bitmap we can find
+        for (int i = 0; i < PREFERRED_BITMAP_ORDER.length; i++) {
+            Bitmap next = getBitmap(PREFERRED_BITMAP_ORDER[i]);
+            if (next != null) {
+                icon = next;
+                break;
+            }
+        }
+
+        // Get the best Uri we can find
+        for (int i = 0; i < PREFERRED_URI_ORDER.length; i++) {
+            String next = getString(PREFERRED_URI_ORDER[i]);
+            if (!TextUtils.isEmpty(next)) {
+                iconUri = Uri.parse(next);
+                break;
+            }
+        }
+
+        Uri mediaUri = null;
+        String mediaUriStr = getString(METADATA_KEY_MEDIA_URI);
+        if (!TextUtils.isEmpty(mediaUriStr)) {
+            mediaUri = Uri.parse(mediaUriStr);
+        }
+
+        MediaDescription.Builder bob = new MediaDescription.Builder();
+        bob.setMediaId(mediaId);
+        bob.setTitle(text[0]);
+        bob.setSubtitle(text[1]);
+        bob.setDescription(text[2]);
+        bob.setIconBitmap(icon);
+        bob.setIconUri(iconUri);
+        bob.setMediaUri(mediaUri);
+        if (mBundle.containsKey(METADATA_KEY_BT_FOLDER_TYPE)) {
+            Bundle bundle = new Bundle();
+            bundle.putLong(MediaDescription.EXTRA_BT_FOLDER_TYPE,
+                    getLong(METADATA_KEY_BT_FOLDER_TYPE));
+            bob.setExtras(bundle);
+        }
+        mDescription = bob.build();
+
+        return mDescription;
+    }
+
+    /**
+     * Helper for getting the String key used by {@link MediaMetadata} from the
+     * integer key that {@link MediaMetadataEditor} uses.
+     *
+     * @param editorKey The key used by the editor
+     * @return The key used by this class or null if no mapping exists
+     * @hide
+     */
+    @UnsupportedAppUsage
+    public static String getKeyFromMetadataEditorKey(int editorKey) {
+        return EDITOR_KEY_MAPPING.get(editorKey, null);
+    }
+
+    public static final Parcelable.Creator<MediaMetadata> CREATOR =
+            new Parcelable.Creator<MediaMetadata>() {
+                @Override
+                public MediaMetadata createFromParcel(Parcel in) {
+                    return new MediaMetadata(in);
+                }
+
+                @Override
+                public MediaMetadata[] newArray(int size) {
+                    return new MediaMetadata[size];
+                }
+            };
+
+    /**
+     * Compares the contents of this object to another MediaMetadata object. It
+     * does not compare Bitmaps and Ratings as the media player can choose to
+     * forgo these fields depending on how you retrieve the MediaMetadata.
+     *
+     * @param o The Metadata object to compare this object against
+     * @return Whether or not the two objects have matching fields (excluding
+     * Bitmaps and Ratings)
+     */
+    @Override
+    public boolean equals(Object o) {
+        if (o == this) {
+            return true;
+        }
+
+        if (!(o instanceof MediaMetadata)) {
+            return false;
+        }
+
+        final MediaMetadata m = (MediaMetadata) o;
+
+        for (int i = 0; i < METADATA_KEYS_TYPE.size(); i++) {
+            String key = METADATA_KEYS_TYPE.keyAt(i);
+            switch (METADATA_KEYS_TYPE.valueAt(i)) {
+                case METADATA_TYPE_TEXT:
+                    if (!Objects.equals(getString(key), m.getString(key))) {
+                        return false;
+                    }
+                    break;
+                case METADATA_TYPE_LONG:
+                    if (getLong(key) != m.getLong(key)) {
+                        return false;
+                    }
+                    break;
+                default:
+                    // Ignore ratings and bitmaps when comparing
+                    break;
+            }
+        }
+
+        return true;
+    }
+
+    @Override
+    public int hashCode() {
+        int hashCode = 17;
+
+        for (int i = 0; i < METADATA_KEYS_TYPE.size(); i++) {
+            String key = METADATA_KEYS_TYPE.keyAt(i);
+            switch (METADATA_KEYS_TYPE.valueAt(i)) {
+                case METADATA_TYPE_TEXT:
+                    hashCode = 31 * hashCode + Objects.hash(getString(key));
+                    break;
+                case METADATA_TYPE_LONG:
+                    hashCode = 31 * hashCode + Long.hashCode(getLong(key));
+                    break;
+                default:
+                    // Ignore ratings and bitmaps when comparing
+                    break;
+            }
+        }
+
+        return hashCode;
+    }
+
+    /**
+     * Use to build MediaMetadata objects. The system defined metadata keys must
+     * use the appropriate data type.
+     */
+    public static final class Builder {
+        private final Bundle mBundle;
+
+        /**
+         * Create an empty Builder. Any field that should be included in the
+         * {@link MediaMetadata} must be added.
+         */
+        public Builder() {
+            mBundle = new Bundle();
+        }
+
+        /**
+         * Create a Builder using a {@link MediaMetadata} instance to set the
+         * initial values. All fields in the source metadata will be included in
+         * the new metadata. Fields can be overwritten by adding the same key.
+         *
+         * @param source
+         */
+        public Builder(MediaMetadata source) {
+            mBundle = new Bundle(source.mBundle);
+        }
+
+        /**
+         * Create a Builder using a {@link MediaMetadata} instance to set
+         * initial values, but replace bitmaps with a scaled down copy if they
+         * are larger than maxBitmapSize.
+         *
+         * @param source The original metadata to copy.
+         * @param maxBitmapSize The maximum height/width for bitmaps contained
+         *            in the metadata.
+         * @hide
+         */
+        public Builder(MediaMetadata source, int maxBitmapSize) {
+            this(source);
+            for (String key : mBundle.keySet()) {
+                Object value = mBundle.get(key);
+                if (value != null && value instanceof Bitmap) {
+                    Bitmap bmp = (Bitmap) value;
+                    if (bmp.getHeight() > maxBitmapSize || bmp.getWidth() > maxBitmapSize) {
+                        putBitmap(key, scaleBitmap(bmp, maxBitmapSize));
+                    }
+                }
+            }
+        }
+
+        /**
+         * Put a CharSequence value into the metadata. Custom keys may be used,
+         * but if the METADATA_KEYs defined in this class are used they may only
+         * be one of the following:
+         * <ul>
+         * <li>{@link #METADATA_KEY_TITLE}</li>
+         * <li>{@link #METADATA_KEY_ARTIST}</li>
+         * <li>{@link #METADATA_KEY_ALBUM}</li>
+         * <li>{@link #METADATA_KEY_AUTHOR}</li>
+         * <li>{@link #METADATA_KEY_WRITER}</li>
+         * <li>{@link #METADATA_KEY_COMPOSER}</li>
+         * <li>{@link #METADATA_KEY_DATE}</li>
+         * <li>{@link #METADATA_KEY_GENRE}</li>
+         * <li>{@link #METADATA_KEY_ALBUM_ARTIST}</li>
+         * <li>{@link #METADATA_KEY_ART_URI}</li>
+         * <li>{@link #METADATA_KEY_ALBUM_ART_URI}</li>
+         * <li>{@link #METADATA_KEY_DISPLAY_TITLE}</li>
+         * <li>{@link #METADATA_KEY_DISPLAY_SUBTITLE}</li>
+         * <li>{@link #METADATA_KEY_DISPLAY_DESCRIPTION}</li>
+         * <li>{@link #METADATA_KEY_DISPLAY_ICON_URI}</li>
+         * </ul>
+         *
+         * @param key The key for referencing this value
+         * @param value The CharSequence value to store
+         * @return The Builder to allow chaining
+         */
+        public Builder putText(@TextKey String key, CharSequence value) {
+            if (METADATA_KEYS_TYPE.containsKey(key)) {
+                if (METADATA_KEYS_TYPE.get(key) != METADATA_TYPE_TEXT) {
+                    throw new IllegalArgumentException("The " + key
+                            + " key cannot be used to put a CharSequence");
+                }
+            }
+            mBundle.putCharSequence(key, value);
+            return this;
+        }
+
+        /**
+         * Put a String value into the metadata. Custom keys may be used, but if
+         * the METADATA_KEYs defined in this class are used they may only be one
+         * of the following:
+         * <ul>
+         * <li>{@link #METADATA_KEY_TITLE}</li>
+         * <li>{@link #METADATA_KEY_ARTIST}</li>
+         * <li>{@link #METADATA_KEY_ALBUM}</li>
+         * <li>{@link #METADATA_KEY_AUTHOR}</li>
+         * <li>{@link #METADATA_KEY_WRITER}</li>
+         * <li>{@link #METADATA_KEY_COMPOSER}</li>
+         * <li>{@link #METADATA_KEY_DATE}</li>
+         * <li>{@link #METADATA_KEY_GENRE}</li>
+         * <li>{@link #METADATA_KEY_ALBUM_ARTIST}</li>
+         * <li>{@link #METADATA_KEY_ART_URI}</li>
+         * <li>{@link #METADATA_KEY_ALBUM_ART_URI}</li>
+         * <li>{@link #METADATA_KEY_DISPLAY_TITLE}</li>
+         * <li>{@link #METADATA_KEY_DISPLAY_SUBTITLE}</li>
+         * <li>{@link #METADATA_KEY_DISPLAY_DESCRIPTION}</li>
+         * <li>{@link #METADATA_KEY_DISPLAY_ICON_URI}</li>
+         * </ul>
+         * <p>
+         * Uris for artwork should use the content:// style and support
+         * {@link ContentResolver#EXTRA_SIZE} for retrieving scaled artwork
+         * through {@link ContentResolver#openTypedAssetFileDescriptor(Uri,
+         * String, Bundle)}.
+         *
+         * @param key The key for referencing this value
+         * @param value The String value to store
+         * @return The Builder to allow chaining
+         */
+        public Builder putString(@TextKey String key, String value) {
+            if (METADATA_KEYS_TYPE.containsKey(key)) {
+                if (METADATA_KEYS_TYPE.get(key) != METADATA_TYPE_TEXT) {
+                    throw new IllegalArgumentException("The " + key
+                            + " key cannot be used to put a String");
+                }
+            }
+            mBundle.putCharSequence(key, value);
+            return this;
+        }
+
+        /**
+         * Put a long value into the metadata. Custom keys may be used, but if
+         * the METADATA_KEYs defined in this class are used they may only be one
+         * of the following:
+         * <ul>
+         * <li>{@link #METADATA_KEY_DURATION}</li>
+         * <li>{@link #METADATA_KEY_TRACK_NUMBER}</li>
+         * <li>{@link #METADATA_KEY_NUM_TRACKS}</li>
+         * <li>{@link #METADATA_KEY_DISC_NUMBER}</li>
+         * <li>{@link #METADATA_KEY_YEAR}</li>
+         * </ul>
+         *
+         * @param key The key for referencing this value
+         * @param value The long value to store
+         * @return The Builder to allow chaining
+         */
+        public Builder putLong(@LongKey String key, long value) {
+            if (METADATA_KEYS_TYPE.containsKey(key)) {
+                if (METADATA_KEYS_TYPE.get(key) != METADATA_TYPE_LONG) {
+                    throw new IllegalArgumentException("The " + key
+                            + " key cannot be used to put a long");
+                }
+            }
+            mBundle.putLong(key, value);
+            return this;
+        }
+
+        /**
+         * Put a {@link Rating} into the metadata. Custom keys may be used, but
+         * if the METADATA_KEYs defined in this class are used they may only be
+         * one of the following:
+         * <ul>
+         * <li>{@link #METADATA_KEY_RATING}</li>
+         * <li>{@link #METADATA_KEY_USER_RATING}</li>
+         * </ul>
+         *
+         * @param key The key for referencing this value
+         * @param value The Rating value to store
+         * @return The Builder to allow chaining
+         */
+        public Builder putRating(@RatingKey String key, Rating value) {
+            if (METADATA_KEYS_TYPE.containsKey(key)) {
+                if (METADATA_KEYS_TYPE.get(key) != METADATA_TYPE_RATING) {
+                    throw new IllegalArgumentException("The " + key
+                            + " key cannot be used to put a Rating");
+                }
+            }
+            mBundle.putParcelable(key, value);
+            return this;
+        }
+
+        /**
+         * Put a {@link Bitmap} into the metadata. Custom keys may be used, but
+         * if the METADATA_KEYs defined in this class are used they may only be
+         * one of the following:
+         * <ul>
+         * <li>{@link #METADATA_KEY_ART}</li>
+         * <li>{@link #METADATA_KEY_ALBUM_ART}</li>
+         * <li>{@link #METADATA_KEY_DISPLAY_ICON}</li>
+         * </ul>
+         * <p>
+         * Large bitmaps may be scaled down by the system when
+         * {@link android.media.session.MediaSession#setMetadata} is called.
+         * To pass full resolution images {@link Uri Uris} should be used with
+         * {@link #putString}.
+         *
+         * @param key The key for referencing this value
+         * @param value The Bitmap to store
+         * @return The Builder to allow chaining
+         */
+        public Builder putBitmap(@BitmapKey String key, Bitmap value) {
+            if (METADATA_KEYS_TYPE.containsKey(key)) {
+                if (METADATA_KEYS_TYPE.get(key) != METADATA_TYPE_BITMAP) {
+                    throw new IllegalArgumentException("The " + key
+                            + " key cannot be used to put a Bitmap");
+                }
+            }
+            mBundle.putParcelable(key, value);
+            return this;
+        }
+
+        /**
+         * Creates a {@link MediaMetadata} instance with the specified fields.
+         *
+         * @return The new MediaMetadata instance
+         */
+        public MediaMetadata build() {
+            return new MediaMetadata(mBundle);
+        }
+
+        private Bitmap scaleBitmap(Bitmap bmp, int maxSize) {
+            float maxSizeF = maxSize;
+            float widthScale = maxSizeF / bmp.getWidth();
+            float heightScale = maxSizeF / bmp.getHeight();
+            float scale = Math.min(widthScale, heightScale);
+            int height = (int) (bmp.getHeight() * scale);
+            int width = (int) (bmp.getWidth() * scale);
+            return Bitmap.createScaledBitmap(bmp, width, height, true);
+        }
+    }
+}
diff --git a/packages/MediaComponents/apex/java/android/media/Rating.aidl b/packages/MediaComponents/apex/java/android/media/Rating.aidl
new file mode 100644
index 0000000..1dc336a
--- /dev/null
+++ b/packages/MediaComponents/apex/java/android/media/Rating.aidl
@@ -0,0 +1,19 @@
+/*
+ * Copyright (C) 2013 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package android.media;
+
+parcelable Rating;
diff --git a/packages/MediaComponents/apex/java/android/media/Rating.java b/packages/MediaComponents/apex/java/android/media/Rating.java
new file mode 100644
index 0000000..04d5364
--- /dev/null
+++ b/packages/MediaComponents/apex/java/android/media/Rating.java
@@ -0,0 +1,308 @@
+/*
+ * Copyright (C) 2013 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package android.media;
+
+import android.annotation.IntDef;
+import android.os.Parcel;
+import android.os.Parcelable;
+import android.util.Log;
+
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+
+/**
+ * A class to encapsulate rating information used as content metadata.
+ * A rating is defined by its rating style (see {@link #RATING_HEART},
+ * {@link #RATING_THUMB_UP_DOWN}, {@link #RATING_3_STARS}, {@link #RATING_4_STARS},
+ * {@link #RATING_5_STARS} or {@link #RATING_PERCENTAGE}) and the actual rating value (which may
+ * be defined as "unrated"), both of which are defined when the rating instance is constructed
+ * through one of the factory methods.
+ */
+public final class Rating implements Parcelable {
+    private final static String TAG = "Rating";
+
+    /**
+     * @hide
+     */
+    @IntDef({RATING_NONE, RATING_HEART, RATING_THUMB_UP_DOWN, RATING_3_STARS, RATING_4_STARS,
+            RATING_5_STARS, RATING_PERCENTAGE})
+    @Retention(RetentionPolicy.SOURCE)
+    public @interface Style {}
+
+    /**
+     * @hide
+     */
+    @IntDef({RATING_3_STARS, RATING_4_STARS, RATING_5_STARS})
+    @Retention(RetentionPolicy.SOURCE)
+    public @interface StarStyle {}
+
+    /**
+     * Indicates a rating style is not supported. A Rating will never have this
+     * type, but can be used by other classes to indicate they do not support
+     * Rating.
+     */
+    public final static int RATING_NONE = 0;
+
+    /**
+     * A rating style with a single degree of rating, "heart" vs "no heart". Can be used to
+     * indicate the content referred to is a favorite (or not).
+     */
+    public final static int RATING_HEART = 1;
+
+    /**
+     * A rating style for "thumb up" vs "thumb down".
+     */
+    public final static int RATING_THUMB_UP_DOWN = 2;
+
+    /**
+     * A rating style with 0 to 3 stars.
+     */
+    public final static int RATING_3_STARS = 3;
+
+    /**
+     * A rating style with 0 to 4 stars.
+     */
+    public final static int RATING_4_STARS = 4;
+
+    /**
+     * A rating style with 0 to 5 stars.
+     */
+    public final static int RATING_5_STARS = 5;
+
+    /**
+     * A rating style expressed as a percentage.
+     */
+    public final static int RATING_PERCENTAGE = 6;
+
+    private final static float RATING_NOT_RATED = -1.0f;
+
+    private final int mRatingStyle;
+
+    private final float mRatingValue;
+
+    private Rating(@Style int ratingStyle, float rating) {
+        mRatingStyle = ratingStyle;
+        mRatingValue = rating;
+    }
+
+    @Override
+    public String toString() {
+        return "Rating:style=" + mRatingStyle + " rating="
+                + (mRatingValue < 0.0f ? "unrated" : String.valueOf(mRatingValue));
+    }
+
+    @Override
+    public int describeContents() {
+        return mRatingStyle;
+    }
+
+    @Override
+    public void writeToParcel(Parcel dest, int flags) {
+        dest.writeInt(mRatingStyle);
+        dest.writeFloat(mRatingValue);
+    }
+
+    public static final Parcelable.Creator<Rating> CREATOR
+            = new Parcelable.Creator<Rating>() {
+        /**
+         * Rebuilds a Rating previously stored with writeToParcel().
+         * @param p    Parcel object to read the Rating from
+         * @return a new Rating created from the data in the parcel
+         */
+        @Override
+        public Rating createFromParcel(Parcel p) {
+            return new Rating(p.readInt(), p.readFloat());
+        }
+
+        @Override
+        public Rating[] newArray(int size) {
+            return new Rating[size];
+        }
+    };
+
+    /**
+     * Return a Rating instance with no rating.
+     * Create and return a new Rating instance with no rating known for the given
+     * rating style.
+     * @param ratingStyle one of {@link #RATING_HEART}, {@link #RATING_THUMB_UP_DOWN},
+     *    {@link #RATING_3_STARS}, {@link #RATING_4_STARS}, {@link #RATING_5_STARS},
+     *    or {@link #RATING_PERCENTAGE}.
+     * @return null if an invalid rating style is passed, a new Rating instance otherwise.
+     */
+    public static Rating newUnratedRating(@Style int ratingStyle) {
+        switch(ratingStyle) {
+            case RATING_HEART:
+            case RATING_THUMB_UP_DOWN:
+            case RATING_3_STARS:
+            case RATING_4_STARS:
+            case RATING_5_STARS:
+            case RATING_PERCENTAGE:
+                return new Rating(ratingStyle, RATING_NOT_RATED);
+            default:
+                return null;
+        }
+    }
+
+    /**
+     * Return a Rating instance with a heart-based rating.
+     * Create and return a new Rating instance with a rating style of {@link #RATING_HEART},
+     * and a heart-based rating.
+     * @param hasHeart true for a "heart selected" rating, false for "heart unselected".
+     * @return a new Rating instance.
+     */
+    public static Rating newHeartRating(boolean hasHeart) {
+        return new Rating(RATING_HEART, hasHeart ? 1.0f : 0.0f);
+    }
+
+    /**
+     * Return a Rating instance with a thumb-based rating.
+     * Create and return a new Rating instance with a {@link #RATING_THUMB_UP_DOWN}
+     * rating style, and a "thumb up" or "thumb down" rating.
+     * @param thumbIsUp true for a "thumb up" rating, false for "thumb down".
+     * @return a new Rating instance.
+     */
+    public static Rating newThumbRating(boolean thumbIsUp) {
+        return new Rating(RATING_THUMB_UP_DOWN, thumbIsUp ? 1.0f : 0.0f);
+    }
+
+    /**
+     * Return a Rating instance with a star-based rating.
+     * Create and return a new Rating instance with one of the star-base rating styles
+     * and the given integer or fractional number of stars. Non integer values can for instance
+     * be used to represent an average rating value, which might not be an integer number of stars.
+     * @param starRatingStyle one of {@link #RATING_3_STARS}, {@link #RATING_4_STARS},
+     *     {@link #RATING_5_STARS}.
+     * @param starRating a number ranging from 0.0f to 3.0f, 4.0f or 5.0f according to
+     *     the rating style.
+     * @return null if the rating style is invalid, or the rating is out of range,
+     *     a new Rating instance otherwise.
+     */
+    public static Rating newStarRating(@StarStyle int starRatingStyle, float starRating) {
+        float maxRating = -1.0f;
+        switch(starRatingStyle) {
+            case RATING_3_STARS:
+                maxRating = 3.0f;
+                break;
+            case RATING_4_STARS:
+                maxRating = 4.0f;
+                break;
+            case RATING_5_STARS:
+                maxRating = 5.0f;
+                break;
+            default:
+                Log.e(TAG, "Invalid rating style (" + starRatingStyle + ") for a star rating");
+                        return null;
+        }
+        if ((starRating < 0.0f) || (starRating > maxRating)) {
+            Log.e(TAG, "Trying to set out of range star-based rating");
+            return null;
+        }
+        return new Rating(starRatingStyle, starRating);
+    }
+
+    /**
+     * Return a Rating instance with a percentage-based rating.
+     * Create and return a new Rating instance with a {@link #RATING_PERCENTAGE}
+     * rating style, and a rating of the given percentage.
+     * @param percent the value of the rating
+     * @return null if the rating is out of range, a new Rating instance otherwise.
+     */
+    public static Rating newPercentageRating(float percent) {
+        if ((percent < 0.0f) || (percent > 100.0f)) {
+            Log.e(TAG, "Invalid percentage-based rating value");
+            return null;
+        } else {
+            return new Rating(RATING_PERCENTAGE, percent);
+        }
+    }
+
+    /**
+     * Return whether there is a rating value available.
+     * @return true if the instance was not created with {@link #newUnratedRating(int)}.
+     */
+    public boolean isRated() {
+        return mRatingValue >= 0.0f;
+    }
+
+    /**
+     * Return the rating style.
+     * @return one of {@link #RATING_HEART}, {@link #RATING_THUMB_UP_DOWN},
+     *    {@link #RATING_3_STARS}, {@link #RATING_4_STARS}, {@link #RATING_5_STARS},
+     *    or {@link #RATING_PERCENTAGE}.
+     */
+    @Style
+    public int getRatingStyle() {
+        return mRatingStyle;
+    }
+
+    /**
+     * Return whether the rating is "heart selected".
+     * @return true if the rating is "heart selected", false if the rating is "heart unselected",
+     *    if the rating style is not {@link #RATING_HEART} or if it is unrated.
+     */
+    public boolean hasHeart() {
+        if (mRatingStyle != RATING_HEART) {
+            return false;
+        } else {
+            return (mRatingValue == 1.0f);
+        }
+    }
+
+    /**
+     * Return whether the rating is "thumb up".
+     * @return true if the rating is "thumb up", false if the rating is "thumb down",
+     *    if the rating style is not {@link #RATING_THUMB_UP_DOWN} or if it is unrated.
+     */
+    public boolean isThumbUp() {
+        if (mRatingStyle != RATING_THUMB_UP_DOWN) {
+            return false;
+        } else {
+            return (mRatingValue == 1.0f);
+        }
+    }
+
+    /**
+     * Return the star-based rating value.
+     * @return a rating value greater or equal to 0.0f, or a negative value if the rating style is
+     *    not star-based, or if it is unrated.
+     */
+    public float getStarRating() {
+        switch (mRatingStyle) {
+            case RATING_3_STARS:
+            case RATING_4_STARS:
+            case RATING_5_STARS:
+                if (isRated()) {
+                    return mRatingValue;
+                }
+            default:
+                return -1.0f;
+        }
+    }
+
+    /**
+     * Return the percentage-based rating value.
+     * @return a rating value greater or equal to 0.0f, or a negative value if the rating style is
+     *    not percentage-based, or if it is unrated.
+     */
+    public float getPercentRating() {
+        if ((mRatingStyle != RATING_PERCENTAGE) || !isRated()) {
+            return -1.0f;
+        } else {
+            return mRatingValue;
+        }
+    }
+}
diff --git a/packages/MediaComponents/apex/java/android/media/VolumeProvider.java b/packages/MediaComponents/apex/java/android/media/VolumeProvider.java
new file mode 100644
index 0000000..1c017c5
--- /dev/null
+++ b/packages/MediaComponents/apex/java/android/media/VolumeProvider.java
@@ -0,0 +1,161 @@
+/*
+ * Copyright (C) 2014 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package android.media;
+
+import android.annotation.IntDef;
+import android.media.session.MediaSession;
+
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+
+/**
+ * Handles requests to adjust or set the volume on a session. This is also used
+ * to push volume updates back to the session. The provider must call
+ * {@link #setCurrentVolume(int)} each time the volume being provided changes.
+ * <p>
+ * You can set a volume provider on a session by calling
+ * {@link MediaSession#setPlaybackToRemote}.
+ */
+public abstract class VolumeProvider {
+
+    /**
+     * @hide
+     */
+    @IntDef({VOLUME_CONTROL_FIXED, VOLUME_CONTROL_RELATIVE, VOLUME_CONTROL_ABSOLUTE})
+    @Retention(RetentionPolicy.SOURCE)
+    public @interface ControlType {}
+
+    /**
+     * The volume is fixed and can not be modified. Requests to change volume
+     * should be ignored.
+     */
+    public static final int VOLUME_CONTROL_FIXED = 0;
+
+    /**
+     * The volume control uses relative adjustment via
+     * {@link #onAdjustVolume(int)}. Attempts to set the volume to a specific
+     * value should be ignored.
+     */
+    public static final int VOLUME_CONTROL_RELATIVE = 1;
+
+    /**
+     * The volume control uses an absolute value. It may be adjusted using
+     * {@link #onAdjustVolume(int)} or set directly using
+     * {@link #onSetVolumeTo(int)}.
+     */
+    public static final int VOLUME_CONTROL_ABSOLUTE = 2;
+
+    private final int mControlType;
+    private final int mMaxVolume;
+    private int mCurrentVolume;
+    private Callback mCallback;
+
+    /**
+     * Create a new volume provider for handling volume events. You must specify
+     * the type of volume control, the maximum volume that can be used, and the
+     * current volume on the output.
+     *
+     * @param volumeControl The method for controlling volume that is used by
+     *            this provider.
+     * @param maxVolume The maximum allowed volume.
+     * @param currentVolume The current volume on the output.
+     */
+    public VolumeProvider(@ControlType int volumeControl, int maxVolume, int currentVolume) {
+        mControlType = volumeControl;
+        mMaxVolume = maxVolume;
+        mCurrentVolume = currentVolume;
+    }
+
+    /**
+     * Get the volume control type that this volume provider uses.
+     *
+     * @return The volume control type for this volume provider
+     */
+    @ControlType
+    public final int getVolumeControl() {
+        return mControlType;
+    }
+
+    /**
+     * Get the maximum volume this provider allows.
+     *
+     * @return The max allowed volume.
+     */
+    public final int getMaxVolume() {
+        return mMaxVolume;
+    }
+
+    /**
+     * Gets the current volume. This will be the last value set by
+     * {@link #setCurrentVolume(int)}.
+     *
+     * @return The current volume.
+     */
+    public final int getCurrentVolume() {
+        return mCurrentVolume;
+    }
+
+    /**
+     * Notify the system that the current volume has been changed. This must be
+     * called every time the volume changes to ensure it is displayed properly.
+     *
+     * @param currentVolume The current volume on the output.
+     */
+    public final void setCurrentVolume(int currentVolume) {
+        mCurrentVolume = currentVolume;
+        if (mCallback != null) {
+            mCallback.onVolumeChanged(this);
+        }
+    }
+
+    /**
+     * Override to handle requests to set the volume of the current output.
+     * After the volume has been modified {@link #setCurrentVolume} must be
+     * called to notify the system.
+     *
+     * @param volume The volume to set the output to.
+     */
+    public void onSetVolumeTo(int volume) {
+    }
+
+    /**
+     * Override to handle requests to adjust the volume of the current output.
+     * Direction will be one of {@link AudioManager#ADJUST_LOWER},
+     * {@link AudioManager#ADJUST_RAISE}, {@link AudioManager#ADJUST_SAME}.
+     * After the volume has been modified {@link #setCurrentVolume} must be
+     * called to notify the system.
+     *
+     * @param direction The direction to change the volume in.
+     */
+    public void onAdjustVolume(int direction) {
+    }
+
+    /**
+     * Sets a callback to receive volume changes.
+     * @hide
+     */
+    public void setCallback(Callback callback) {
+        mCallback = callback;
+    }
+
+    /**
+     * Listens for changes to the volume.
+     * @hide
+     */
+    public static abstract class Callback {
+        public abstract void onVolumeChanged(VolumeProvider volumeProvider);
+    }
+}
diff --git a/packages/MediaComponents/apex/java/android/media/browse/MediaBrowser.aidl b/packages/MediaComponents/apex/java/android/media/browse/MediaBrowser.aidl
new file mode 100644
index 0000000..782e094
--- /dev/null
+++ b/packages/MediaComponents/apex/java/android/media/browse/MediaBrowser.aidl
@@ -0,0 +1,18 @@
+/* Copyright 2014, The Android Open Source Project
+**
+** Licensed under the Apache License, Version 2.0 (the "License");
+** you may not use this file except in compliance with the License.
+** You may obtain a copy of the License at
+**
+**     http://www.apache.org/licenses/LICENSE-2.0
+**
+** Unless required by applicable law or agreed to in writing, software
+** distributed under the License is distributed on an "AS IS" BASIS,
+** WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+** See the License for the specific language governing permissions and
+** limitations under the License.
+*/
+
+package android.media.browse;
+
+parcelable MediaBrowser.MediaItem;
\ No newline at end of file
diff --git a/packages/MediaComponents/apex/java/android/media/browse/MediaBrowser.java b/packages/MediaComponents/apex/java/android/media/browse/MediaBrowser.java
new file mode 100644
index 0000000..2bccd88
--- /dev/null
+++ b/packages/MediaComponents/apex/java/android/media/browse/MediaBrowser.java
@@ -0,0 +1,1171 @@
+/*
+ * Copyright (C) 2014 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package android.media.browse;
+
+import android.annotation.IntDef;
+import android.annotation.NonNull;
+import android.annotation.Nullable;
+import android.content.ComponentName;
+import android.content.Context;
+import android.content.Intent;
+import android.content.ServiceConnection;
+import android.content.pm.ParceledListSlice;
+import android.media.MediaDescription;
+import android.media.session.MediaController;
+import android.media.session.MediaSession;
+import android.os.Binder;
+import android.os.Bundle;
+import android.os.Handler;
+import android.os.IBinder;
+import android.os.Parcel;
+import android.os.Parcelable;
+import android.os.RemoteException;
+import android.os.ResultReceiver;
+import android.service.media.IMediaBrowserService;
+import android.service.media.IMediaBrowserServiceCallbacks;
+import android.service.media.MediaBrowserService;
+import android.text.TextUtils;
+import android.util.ArrayMap;
+import android.util.Log;
+
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.ref.WeakReference;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Map.Entry;
+
+/**
+ * Browses media content offered by a link MediaBrowserService.
+ * <p>
+ * This object is not thread-safe. All calls should happen on the thread on which the browser
+ * was constructed.
+ * </p>
+ * <h3>Standard Extra Data</h3>
+ *
+ * <p>These are the current standard fields that can be used as extra data via
+ * {@link #subscribe(String, Bundle, SubscriptionCallback)},
+ * {@link #unsubscribe(String, SubscriptionCallback)}, and
+ * {@link SubscriptionCallback#onChildrenLoaded(String, List, Bundle)}.
+ *
+ * <ul>
+ *     <li> {@link #EXTRA_PAGE}
+ *     <li> {@link #EXTRA_PAGE_SIZE}
+ * </ul>
+ */
+public final class MediaBrowser {
+    private static final String TAG = "MediaBrowser";
+    private static final boolean DBG = false;
+
+    /**
+     * Used as an int extra field to denote the page number to subscribe.
+     * The value of {@code EXTRA_PAGE} should be greater than or equal to 0.
+     *
+     * @see #EXTRA_PAGE_SIZE
+     */
+    public static final String EXTRA_PAGE = "android.media.browse.extra.PAGE";
+
+    /**
+     * Used as an int extra field to denote the number of media items in a page.
+     * The value of {@code EXTRA_PAGE_SIZE} should be greater than or equal to 1.
+     *
+     * @see #EXTRA_PAGE
+     */
+    public static final String EXTRA_PAGE_SIZE = "android.media.browse.extra.PAGE_SIZE";
+
+    private static final int CONNECT_STATE_DISCONNECTING = 0;
+    private static final int CONNECT_STATE_DISCONNECTED = 1;
+    private static final int CONNECT_STATE_CONNECTING = 2;
+    private static final int CONNECT_STATE_CONNECTED = 3;
+    private static final int CONNECT_STATE_SUSPENDED = 4;
+
+    private final Context mContext;
+    private final ComponentName mServiceComponent;
+    private final ConnectionCallback mCallback;
+    private final Bundle mRootHints;
+    private final Handler mHandler = new Handler();
+    private final ArrayMap<String, Subscription> mSubscriptions = new ArrayMap<>();
+
+    private volatile int mState = CONNECT_STATE_DISCONNECTED;
+    private volatile String mRootId;
+    private volatile MediaSession.Token mMediaSessionToken;
+    private volatile Bundle mExtras;
+
+    private MediaServiceConnection mServiceConnection;
+    private IMediaBrowserService mServiceBinder;
+    private IMediaBrowserServiceCallbacks mServiceCallbacks;
+
+    /**
+     * Creates a media browser for the specified media browser service.
+     *
+     * @param context The context.
+     * @param serviceComponent The component name of the media browser service.
+     * @param callback The connection callback.
+     * @param rootHints An optional bundle of service-specific arguments to send
+     * to the media browser service when connecting and retrieving the root id
+     * for browsing, or null if none. The contents of this bundle may affect
+     * the information returned when browsing.
+     * @see android.service.media.MediaBrowserService.BrowserRoot#EXTRA_RECENT
+     * @see android.service.media.MediaBrowserService.BrowserRoot#EXTRA_OFFLINE
+     * @see android.service.media.MediaBrowserService.BrowserRoot#EXTRA_SUGGESTED
+     */
+    public MediaBrowser(Context context, ComponentName serviceComponent,
+            ConnectionCallback callback, Bundle rootHints) {
+        if (context == null) {
+            throw new IllegalArgumentException("context must not be null");
+        }
+        if (serviceComponent == null) {
+            throw new IllegalArgumentException("service component must not be null");
+        }
+        if (callback == null) {
+            throw new IllegalArgumentException("connection callback must not be null");
+        }
+        mContext = context;
+        mServiceComponent = serviceComponent;
+        mCallback = callback;
+        mRootHints = rootHints == null ? null : new Bundle(rootHints);
+    }
+
+    /**
+     * Connects to the media browser service.
+     * <p>
+     * The connection callback specified in the constructor will be invoked
+     * when the connection completes or fails.
+     * </p>
+     */
+    public void connect() {
+        if (mState != CONNECT_STATE_DISCONNECTING && mState != CONNECT_STATE_DISCONNECTED) {
+            throw new IllegalStateException("connect() called while neither disconnecting nor "
+                    + "disconnected (state=" + getStateLabel(mState) + ")");
+        }
+
+        mState = CONNECT_STATE_CONNECTING;
+        mHandler.post(new Runnable() {
+            @Override
+            public void run() {
+                if (mState == CONNECT_STATE_DISCONNECTING) {
+                    return;
+                }
+                mState = CONNECT_STATE_CONNECTING;
+                // TODO: remove this extra check.
+                if (DBG) {
+                    if (mServiceConnection != null) {
+                        throw new RuntimeException("mServiceConnection should be null. Instead it"
+                                + " is " + mServiceConnection);
+                    }
+                }
+                if (mServiceBinder != null) {
+                    throw new RuntimeException("mServiceBinder should be null. Instead it is "
+                            + mServiceBinder);
+                }
+                if (mServiceCallbacks != null) {
+                    throw new RuntimeException("mServiceCallbacks should be null. Instead it is "
+                            + mServiceCallbacks);
+                }
+
+                final Intent intent = new Intent(MediaBrowserService.SERVICE_INTERFACE);
+                intent.setComponent(mServiceComponent);
+
+                mServiceConnection = new MediaServiceConnection();
+
+                boolean bound = false;
+                try {
+                    bound = mContext.bindService(intent, mServiceConnection,
+                            Context.BIND_AUTO_CREATE);
+                } catch (Exception ex) {
+                    Log.e(TAG, "Failed binding to service " + mServiceComponent);
+                }
+
+                if (!bound) {
+                    // Tell them that it didn't work.
+                    forceCloseConnection();
+                    mCallback.onConnectionFailed();
+                }
+
+                if (DBG) {
+                    Log.d(TAG, "connect...");
+                    dump();
+                }
+            }
+        });
+    }
+
+    /**
+     * Disconnects from the media browser service.
+     * After this, no more callbacks will be received.
+     */
+    public void disconnect() {
+        // It's ok to call this any state, because allowing this lets apps not have
+        // to check isConnected() unnecessarily. They won't appreciate the extra
+        // assertions for this. We do everything we can here to go back to a sane state.
+        mState = CONNECT_STATE_DISCONNECTING;
+        mHandler.post(new Runnable() {
+            @Override
+            public void run() {
+                // connect() could be called before this. Then we will disconnect and reconnect.
+                if (mServiceCallbacks != null) {
+                    try {
+                        mServiceBinder.disconnect(mServiceCallbacks);
+                    } catch (RemoteException ex) {
+                        // We are disconnecting anyway. Log, just for posterity but it's not
+                        // a big problem.
+                        Log.w(TAG, "RemoteException during connect for " + mServiceComponent);
+                    }
+                }
+                int state = mState;
+                forceCloseConnection();
+                // If the state was not CONNECT_STATE_DISCONNECTING, keep the state so that
+                // the operation came after disconnect() can be handled properly.
+                if (state != CONNECT_STATE_DISCONNECTING) {
+                    mState = state;
+                }
+                if (DBG) {
+                    Log.d(TAG, "disconnect...");
+                    dump();
+                }
+            }
+        });
+    }
+
+    /**
+     * Null out the variables and unbind from the service. This doesn't include
+     * calling disconnect on the service, because we only try to do that in the
+     * clean shutdown cases.
+     * <p>
+     * Everywhere that calls this EXCEPT for disconnect() should follow it with
+     * a call to mCallback.onConnectionFailed(). Disconnect doesn't do that callback
+     * for a clean shutdown, but everywhere else is a dirty shutdown and should
+     * notify the app.
+     * <p>
+     * Also, mState should be updated properly. Mostly it should be CONNECT_STATE_DIACONNECTED
+     * except for disconnect().
+     */
+    private void forceCloseConnection() {
+        if (mServiceConnection != null) {
+            try {
+                mContext.unbindService(mServiceConnection);
+            } catch (IllegalArgumentException e) {
+                if (DBG) {
+                    Log.d(TAG, "unbindService failed", e);
+                }
+            }
+        }
+        mState = CONNECT_STATE_DISCONNECTED;
+        mServiceConnection = null;
+        mServiceBinder = null;
+        mServiceCallbacks = null;
+        mRootId = null;
+        mMediaSessionToken = null;
+    }
+
+    /**
+     * Returns whether the browser is connected to the service.
+     */
+    public boolean isConnected() {
+        return mState == CONNECT_STATE_CONNECTED;
+    }
+
+    /**
+     * Gets the service component that the media browser is connected to.
+     */
+    public @NonNull ComponentName getServiceComponent() {
+        if (!isConnected()) {
+            throw new IllegalStateException("getServiceComponent() called while not connected" +
+                    " (state=" + mState + ")");
+        }
+        return mServiceComponent;
+    }
+
+    /**
+     * Gets the root id.
+     * <p>
+     * Note that the root id may become invalid or change when the
+     * browser is disconnected.
+     * </p>
+     *
+     * @throws IllegalStateException if not connected.
+     */
+    public @NonNull String getRoot() {
+        if (!isConnected()) {
+            throw new IllegalStateException("getRoot() called while not connected (state="
+                    + getStateLabel(mState) + ")");
+        }
+        return mRootId;
+    }
+
+    /**
+     * Gets any extras for the media service.
+     *
+     * @throws IllegalStateException if not connected.
+     */
+    public @Nullable Bundle getExtras() {
+        if (!isConnected()) {
+            throw new IllegalStateException("getExtras() called while not connected (state="
+                    + getStateLabel(mState) + ")");
+        }
+        return mExtras;
+    }
+
+    /**
+     * Gets the media session token associated with the media browser.
+     * <p>
+     * Note that the session token may become invalid or change when the
+     * browser is disconnected.
+     * </p>
+     *
+     * @return The session token for the browser, never null.
+     *
+     * @throws IllegalStateException if not connected.
+     */
+     public @NonNull MediaSession.Token getSessionToken() {
+        if (!isConnected()) {
+            throw new IllegalStateException("getSessionToken() called while not connected (state="
+                    + mState + ")");
+        }
+        return mMediaSessionToken;
+    }
+
+    /**
+     * Queries for information about the media items that are contained within
+     * the specified id and subscribes to receive updates when they change.
+     * <p>
+     * The list of subscriptions is maintained even when not connected and is
+     * restored after the reconnection. It is ok to subscribe while not connected
+     * but the results will not be returned until the connection completes.
+     * </p>
+     * <p>
+     * If the id is already subscribed with a different callback then the new
+     * callback will replace the previous one and the child data will be
+     * reloaded.
+     * </p>
+     *
+     * @param parentId The id of the parent media item whose list of children
+     *            will be subscribed.
+     * @param callback The callback to receive the list of children.
+     */
+    public void subscribe(@NonNull String parentId, @NonNull SubscriptionCallback callback) {
+        subscribeInternal(parentId, null, callback);
+    }
+
+    /**
+     * Queries with service-specific arguments for information about the media items
+     * that are contained within the specified id and subscribes to receive updates
+     * when they change.
+     * <p>
+     * The list of subscriptions is maintained even when not connected and is
+     * restored after the reconnection. It is ok to subscribe while not connected
+     * but the results will not be returned until the connection completes.
+     * </p>
+     * <p>
+     * If the id is already subscribed with a different callback then the new
+     * callback will replace the previous one and the child data will be
+     * reloaded.
+     * </p>
+     *
+     * @param parentId The id of the parent media item whose list of children
+     *            will be subscribed.
+     * @param options The bundle of service-specific arguments to send to the media
+     *            browser service. The contents of this bundle may affect the
+     *            information returned when browsing.
+     * @param callback The callback to receive the list of children.
+     */
+    public void subscribe(@NonNull String parentId, @NonNull Bundle options,
+            @NonNull SubscriptionCallback callback) {
+        if (options == null) {
+            throw new IllegalArgumentException("options cannot be null");
+        }
+        subscribeInternal(parentId, new Bundle(options), callback);
+    }
+
+    /**
+     * Unsubscribes for changes to the children of the specified media id.
+     * <p>
+     * The query callback will no longer be invoked for results associated with
+     * this id once this method returns.
+     * </p>
+     *
+     * @param parentId The id of the parent media item whose list of children
+     *            will be unsubscribed.
+     */
+    public void unsubscribe(@NonNull String parentId) {
+        unsubscribeInternal(parentId, null);
+    }
+
+    /**
+     * Unsubscribes for changes to the children of the specified media id through a callback.
+     * <p>
+     * The query callback will no longer be invoked for results associated with
+     * this id once this method returns.
+     * </p>
+     *
+     * @param parentId The id of the parent media item whose list of children
+     *            will be unsubscribed.
+     * @param callback A callback sent to the media browser service to subscribe.
+     */
+    public void unsubscribe(@NonNull String parentId, @NonNull SubscriptionCallback callback) {
+        if (callback == null) {
+            throw new IllegalArgumentException("callback cannot be null");
+        }
+        unsubscribeInternal(parentId, callback);
+    }
+
+    /**
+     * Retrieves a specific {@link MediaItem} from the connected service. Not
+     * all services may support this, so falling back to subscribing to the
+     * parent's id should be used when unavailable.
+     *
+     * @param mediaId The id of the item to retrieve.
+     * @param cb The callback to receive the result on.
+     */
+    public void getItem(final @NonNull String mediaId, @NonNull final ItemCallback cb) {
+        if (TextUtils.isEmpty(mediaId)) {
+            throw new IllegalArgumentException("mediaId cannot be empty.");
+        }
+        if (cb == null) {
+            throw new IllegalArgumentException("cb cannot be null.");
+        }
+        if (mState != CONNECT_STATE_CONNECTED) {
+            Log.i(TAG, "Not connected, unable to retrieve the MediaItem.");
+            mHandler.post(new Runnable() {
+                @Override
+                public void run() {
+                    cb.onError(mediaId);
+                }
+            });
+            return;
+        }
+        ResultReceiver receiver = new ResultReceiver(mHandler) {
+            @Override
+            protected void onReceiveResult(int resultCode, Bundle resultData) {
+                if (!isConnected()) {
+                    return;
+                }
+                if (resultCode != 0 || resultData == null
+                        || !resultData.containsKey(MediaBrowserService.KEY_MEDIA_ITEM)) {
+                    cb.onError(mediaId);
+                    return;
+                }
+                Parcelable item = resultData.getParcelable(MediaBrowserService.KEY_MEDIA_ITEM);
+                if (item != null && !(item instanceof MediaItem)) {
+                    cb.onError(mediaId);
+                    return;
+                }
+                cb.onItemLoaded((MediaItem)item);
+            }
+        };
+        try {
+            mServiceBinder.getMediaItem(mediaId, receiver, mServiceCallbacks);
+        } catch (RemoteException e) {
+            Log.i(TAG, "Remote error getting media item.");
+            mHandler.post(new Runnable() {
+                @Override
+                public void run() {
+                    cb.onError(mediaId);
+                }
+            });
+        }
+    }
+
+    private void subscribeInternal(String parentId, Bundle options, SubscriptionCallback callback) {
+        // Check arguments.
+        if (TextUtils.isEmpty(parentId)) {
+            throw new IllegalArgumentException("parentId cannot be empty.");
+        }
+        if (callback == null) {
+            throw new IllegalArgumentException("callback cannot be null");
+        }
+        // Update or create the subscription.
+        Subscription sub = mSubscriptions.get(parentId);
+        if (sub == null) {
+            sub = new Subscription();
+            mSubscriptions.put(parentId, sub);
+        }
+        sub.putCallback(mContext, options, callback);
+
+        // If we are connected, tell the service that we are watching. If we aren't connected,
+        // the service will be told when we connect.
+        if (isConnected()) {
+            try {
+                if (options == null) {
+                    mServiceBinder.addSubscriptionDeprecated(parentId, mServiceCallbacks);
+                }
+                mServiceBinder.addSubscription(parentId, callback.mToken, options,
+                        mServiceCallbacks);
+            } catch (RemoteException ex) {
+                // Process is crashing. We will disconnect, and upon reconnect we will
+                // automatically reregister. So nothing to do here.
+                Log.d(TAG, "addSubscription failed with RemoteException parentId=" + parentId);
+            }
+        }
+    }
+
+    private void unsubscribeInternal(String parentId, SubscriptionCallback callback) {
+        // Check arguments.
+        if (TextUtils.isEmpty(parentId)) {
+            throw new IllegalArgumentException("parentId cannot be empty.");
+        }
+
+        Subscription sub = mSubscriptions.get(parentId);
+        if (sub == null) {
+            return;
+        }
+        // Tell the service if necessary.
+        try {
+            if (callback == null) {
+                if (isConnected()) {
+                    mServiceBinder.removeSubscriptionDeprecated(parentId, mServiceCallbacks);
+                    mServiceBinder.removeSubscription(parentId, null, mServiceCallbacks);
+                }
+            } else {
+                final List<SubscriptionCallback> callbacks = sub.getCallbacks();
+                final List<Bundle> optionsList = sub.getOptionsList();
+                for (int i = callbacks.size() - 1; i >= 0; --i) {
+                    if (callbacks.get(i) == callback) {
+                        if (isConnected()) {
+                            mServiceBinder.removeSubscription(
+                                    parentId, callback.mToken, mServiceCallbacks);
+                        }
+                        callbacks.remove(i);
+                        optionsList.remove(i);
+                    }
+                }
+            }
+        } catch (RemoteException ex) {
+            // Process is crashing. We will disconnect, and upon reconnect we will
+            // automatically reregister. So nothing to do here.
+            Log.d(TAG, "removeSubscription failed with RemoteException parentId=" + parentId);
+        }
+
+        if (sub.isEmpty() || callback == null) {
+            mSubscriptions.remove(parentId);
+        }
+    }
+
+    /**
+     * For debugging.
+     */
+    private static String getStateLabel(int state) {
+        switch (state) {
+            case CONNECT_STATE_DISCONNECTING:
+                return "CONNECT_STATE_DISCONNECTING";
+            case CONNECT_STATE_DISCONNECTED:
+                return "CONNECT_STATE_DISCONNECTED";
+            case CONNECT_STATE_CONNECTING:
+                return "CONNECT_STATE_CONNECTING";
+            case CONNECT_STATE_CONNECTED:
+                return "CONNECT_STATE_CONNECTED";
+            case CONNECT_STATE_SUSPENDED:
+                return "CONNECT_STATE_SUSPENDED";
+            default:
+                return "UNKNOWN/" + state;
+        }
+    }
+
+    private final void onServiceConnected(final IMediaBrowserServiceCallbacks callback,
+            final String root, final MediaSession.Token session, final Bundle extra) {
+        mHandler.post(new Runnable() {
+            @Override
+            public void run() {
+                // Check to make sure there hasn't been a disconnect or a different
+                // ServiceConnection.
+                if (!isCurrent(callback, "onConnect")) {
+                    return;
+                }
+                // Don't allow them to call us twice.
+                if (mState != CONNECT_STATE_CONNECTING) {
+                    Log.w(TAG, "onConnect from service while mState="
+                            + getStateLabel(mState) + "... ignoring");
+                    return;
+                }
+                mRootId = root;
+                mMediaSessionToken = session;
+                mExtras = extra;
+                mState = CONNECT_STATE_CONNECTED;
+
+                if (DBG) {
+                    Log.d(TAG, "ServiceCallbacks.onConnect...");
+                    dump();
+                }
+                mCallback.onConnected();
+
+                // we may receive some subscriptions before we are connected, so re-subscribe
+                // everything now
+                for (Entry<String, Subscription> subscriptionEntry : mSubscriptions.entrySet()) {
+                    String id = subscriptionEntry.getKey();
+                    Subscription sub = subscriptionEntry.getValue();
+                    List<SubscriptionCallback> callbackList = sub.getCallbacks();
+                    List<Bundle> optionsList = sub.getOptionsList();
+                    for (int i = 0; i < callbackList.size(); ++i) {
+                        try {
+                            mServiceBinder.addSubscription(id, callbackList.get(i).mToken,
+                                    optionsList.get(i), mServiceCallbacks);
+                        } catch (RemoteException ex) {
+                            // Process is crashing. We will disconnect, and upon reconnect we will
+                            // automatically reregister. So nothing to do here.
+                            Log.d(TAG, "addSubscription failed with RemoteException parentId="
+                                    + id);
+                        }
+                    }
+                }
+            }
+        });
+    }
+
+    private final void onConnectionFailed(final IMediaBrowserServiceCallbacks callback) {
+        mHandler.post(new Runnable() {
+            @Override
+            public void run() {
+                Log.e(TAG, "onConnectFailed for " + mServiceComponent);
+
+                // Check to make sure there hasn't been a disconnect or a different
+                // ServiceConnection.
+                if (!isCurrent(callback, "onConnectFailed")) {
+                    return;
+                }
+                // Don't allow them to call us twice.
+                if (mState != CONNECT_STATE_CONNECTING) {
+                    Log.w(TAG, "onConnect from service while mState="
+                            + getStateLabel(mState) + "... ignoring");
+                    return;
+                }
+
+                // Clean up
+                forceCloseConnection();
+
+                // Tell the app.
+                mCallback.onConnectionFailed();
+            }
+        });
+    }
+
+    private final void onLoadChildren(final IMediaBrowserServiceCallbacks callback,
+            final String parentId, final ParceledListSlice list, final Bundle options) {
+        mHandler.post(new Runnable() {
+            @Override
+            public void run() {
+                // Check that there hasn't been a disconnect or a different
+                // ServiceConnection.
+                if (!isCurrent(callback, "onLoadChildren")) {
+                    return;
+                }
+
+                if (DBG) {
+                    Log.d(TAG, "onLoadChildren for " + mServiceComponent + " id=" + parentId);
+                }
+
+                // Check that the subscription is still subscribed.
+                final Subscription subscription = mSubscriptions.get(parentId);
+                if (subscription != null) {
+                    // Tell the app.
+                    SubscriptionCallback subscriptionCallback =
+                            subscription.getCallback(mContext, options);
+                    if (subscriptionCallback != null) {
+                        List<MediaItem> data = list == null ? null : list.getList();
+                        if (options == null) {
+                            if (data == null) {
+                                subscriptionCallback.onError(parentId);
+                            } else {
+                                subscriptionCallback.onChildrenLoaded(parentId, data);
+                            }
+                        } else {
+                            if (data == null) {
+                                subscriptionCallback.onError(parentId, options);
+                            } else {
+                                subscriptionCallback.onChildrenLoaded(parentId, data, options);
+                            }
+                        }
+                        return;
+                    }
+                }
+                if (DBG) {
+                    Log.d(TAG, "onLoadChildren for id that isn't subscribed id=" + parentId);
+                }
+            }
+        });
+    }
+
+    /**
+     * Return true if {@code callback} is the current ServiceCallbacks. Also logs if it's not.
+     */
+    private boolean isCurrent(IMediaBrowserServiceCallbacks callback, String funcName) {
+        if (mServiceCallbacks != callback || mState == CONNECT_STATE_DISCONNECTING
+                || mState == CONNECT_STATE_DISCONNECTED) {
+            if (mState != CONNECT_STATE_DISCONNECTING && mState != CONNECT_STATE_DISCONNECTED) {
+                Log.i(TAG, funcName + " for " + mServiceComponent + " with mServiceConnection="
+                        + mServiceCallbacks + " this=" + this);
+            }
+            return false;
+        }
+        return true;
+    }
+
+    private ServiceCallbacks getNewServiceCallbacks() {
+        return new ServiceCallbacks(this);
+    }
+
+    /**
+     * Log internal state.
+     * @hide
+     */
+    void dump() {
+        Log.d(TAG, "MediaBrowser...");
+        Log.d(TAG, "  mServiceComponent=" + mServiceComponent);
+        Log.d(TAG, "  mCallback=" + mCallback);
+        Log.d(TAG, "  mRootHints=" + mRootHints);
+        Log.d(TAG, "  mState=" + getStateLabel(mState));
+        Log.d(TAG, "  mServiceConnection=" + mServiceConnection);
+        Log.d(TAG, "  mServiceBinder=" + mServiceBinder);
+        Log.d(TAG, "  mServiceCallbacks=" + mServiceCallbacks);
+        Log.d(TAG, "  mRootId=" + mRootId);
+        Log.d(TAG, "  mMediaSessionToken=" + mMediaSessionToken);
+    }
+
+    /**
+     * A class with information on a single media item for use in browsing/searching media.
+     * MediaItems are application dependent so we cannot guarantee that they contain the
+     * right values.
+     */
+    public static class MediaItem implements Parcelable {
+        private final int mFlags;
+        private final MediaDescription mDescription;
+
+        /** @hide */
+        @Retention(RetentionPolicy.SOURCE)
+        @IntDef(flag=true, value = { FLAG_BROWSABLE, FLAG_PLAYABLE })
+        public @interface Flags { }
+
+        /**
+         * Flag: Indicates that the item has children of its own.
+         */
+        public static final int FLAG_BROWSABLE = 1 << 0;
+
+        /**
+         * Flag: Indicates that the item is playable.
+         * <p>
+         * The id of this item may be passed to
+         * {@link MediaController.TransportControls#playFromMediaId(String, Bundle)}
+         * to start playing it.
+         * </p>
+         */
+        public static final int FLAG_PLAYABLE = 1 << 1;
+
+        /**
+         * Create a new MediaItem for use in browsing media.
+         * @param description The description of the media, which must include a
+         *            media id.
+         * @param flags The flags for this item.
+         */
+        public MediaItem(@NonNull MediaDescription description, @Flags int flags) {
+            if (description == null) {
+                throw new IllegalArgumentException("description cannot be null");
+            }
+            if (TextUtils.isEmpty(description.getMediaId())) {
+                throw new IllegalArgumentException("description must have a non-empty media id");
+            }
+            mFlags = flags;
+            mDescription = description;
+        }
+
+        /**
+         * Private constructor.
+         */
+        private MediaItem(Parcel in) {
+            mFlags = in.readInt();
+            mDescription = MediaDescription.CREATOR.createFromParcel(in);
+        }
+
+        @Override
+        public int describeContents() {
+            return 0;
+        }
+
+        @Override
+        public void writeToParcel(Parcel out, int flags) {
+            out.writeInt(mFlags);
+            mDescription.writeToParcel(out, flags);
+        }
+
+        @Override
+        public String toString() {
+            final StringBuilder sb = new StringBuilder("MediaItem{");
+            sb.append("mFlags=").append(mFlags);
+            sb.append(", mDescription=").append(mDescription);
+            sb.append('}');
+            return sb.toString();
+        }
+
+        public static final Parcelable.Creator<MediaItem> CREATOR =
+                new Parcelable.Creator<MediaItem>() {
+                    @Override
+                    public MediaItem createFromParcel(Parcel in) {
+                        return new MediaItem(in);
+                    }
+
+                    @Override
+                    public MediaItem[] newArray(int size) {
+                        return new MediaItem[size];
+                    }
+                };
+
+        /**
+         * Gets the flags of the item.
+         */
+        public @Flags int getFlags() {
+            return mFlags;
+        }
+
+        /**
+         * Returns whether this item is browsable.
+         * @see #FLAG_BROWSABLE
+         */
+        public boolean isBrowsable() {
+            return (mFlags & FLAG_BROWSABLE) != 0;
+        }
+
+        /**
+         * Returns whether this item is playable.
+         * @see #FLAG_PLAYABLE
+         */
+        public boolean isPlayable() {
+            return (mFlags & FLAG_PLAYABLE) != 0;
+        }
+
+        /**
+         * Returns the description of the media.
+         */
+        public @NonNull MediaDescription getDescription() {
+            return mDescription;
+        }
+
+        /**
+         * Returns the media id in the {@link MediaDescription} for this item.
+         * @see android.media.MediaMetadata#METADATA_KEY_MEDIA_ID
+         */
+        public @Nullable String getMediaId() {
+            return mDescription.getMediaId();
+        }
+    }
+
+    /**
+     * Callbacks for connection related events.
+     */
+    public static class ConnectionCallback {
+        /**
+         * Invoked after {@link MediaBrowser#connect()} when the request has successfully completed.
+         */
+        public void onConnected() {
+        }
+
+        /**
+         * Invoked when the client is disconnected from the media browser.
+         */
+        public void onConnectionSuspended() {
+        }
+
+        /**
+         * Invoked when the connection to the media browser failed.
+         */
+        public void onConnectionFailed() {
+        }
+    }
+
+    /**
+     * Callbacks for subscription related events.
+     */
+    public static abstract class SubscriptionCallback {
+        Binder mToken;
+
+        public SubscriptionCallback() {
+            mToken = new Binder();
+        }
+
+        /**
+         * Called when the list of children is loaded or updated.
+         *
+         * @param parentId The media id of the parent media item.
+         * @param children The children which were loaded.
+         */
+        public void onChildrenLoaded(@NonNull String parentId, @NonNull List<MediaItem> children) {
+        }
+
+        /**
+         * Called when the list of children is loaded or updated.
+         *
+         * @param parentId The media id of the parent media item.
+         * @param children The children which were loaded.
+         * @param options The bundle of service-specific arguments sent to the media
+         *            browser service. The contents of this bundle may affect the
+         *            information returned when browsing.
+         */
+        public void onChildrenLoaded(@NonNull String parentId, @NonNull List<MediaItem> children,
+                @NonNull Bundle options) {
+        }
+
+        /**
+         * Called when the id doesn't exist or other errors in subscribing.
+         * <p>
+         * If this is called, the subscription remains until {@link MediaBrowser#unsubscribe}
+         * called, because some errors may heal themselves.
+         * </p>
+         *
+         * @param parentId The media id of the parent media item whose children could
+         *            not be loaded.
+         */
+        public void onError(@NonNull String parentId) {
+        }
+
+        /**
+         * Called when the id doesn't exist or other errors in subscribing.
+         * <p>
+         * If this is called, the subscription remains until {@link MediaBrowser#unsubscribe}
+         * called, because some errors may heal themselves.
+         * </p>
+         *
+         * @param parentId The media id of the parent media item whose children could
+         *            not be loaded.
+         * @param options The bundle of service-specific arguments sent to the media
+         *            browser service.
+         */
+        public void onError(@NonNull String parentId, @NonNull Bundle options) {
+        }
+    }
+
+    /**
+     * Callback for receiving the result of {@link #getItem}.
+     */
+    public static abstract class ItemCallback {
+        /**
+         * Called when the item has been returned by the connected service.
+         *
+         * @param item The item that was returned or null if it doesn't exist.
+         */
+        public void onItemLoaded(MediaItem item) {
+        }
+
+        /**
+         * Called there was an error retrieving it or the connected service doesn't support
+         * {@link #getItem}.
+         *
+         * @param mediaId The media id of the media item which could not be loaded.
+         */
+        public void onError(@NonNull String mediaId) {
+        }
+    }
+
+    /**
+     * ServiceConnection to the other app.
+     */
+    private class MediaServiceConnection implements ServiceConnection {
+        @Override
+        public void onServiceConnected(final ComponentName name, final IBinder binder) {
+            postOrRun(new Runnable() {
+                @Override
+                public void run() {
+                    if (DBG) {
+                        Log.d(TAG, "MediaServiceConnection.onServiceConnected name=" + name
+                                + " binder=" + binder);
+                        dump();
+                    }
+
+                    // Make sure we are still the current connection, and that they haven't called
+                    // disconnect().
+                    if (!isCurrent("onServiceConnected")) {
+                        return;
+                    }
+
+                    // Save their binder
+                    mServiceBinder = IMediaBrowserService.Stub.asInterface(binder);
+
+                    // We make a new mServiceCallbacks each time we connect so that we can drop
+                    // responses from previous connections.
+                    mServiceCallbacks = getNewServiceCallbacks();
+                    mState = CONNECT_STATE_CONNECTING;
+
+                    // Call connect, which is async. When we get a response from that we will
+                    // say that we're connected.
+                    try {
+                        if (DBG) {
+                            Log.d(TAG, "ServiceCallbacks.onConnect...");
+                            dump();
+                        }
+                        mServiceBinder.connect(mContext.getPackageName(), mRootHints,
+                                mServiceCallbacks);
+                    } catch (RemoteException ex) {
+                        // Connect failed, which isn't good. But the auto-reconnect on the service
+                        // will take over and we will come back. We will also get the
+                        // onServiceDisconnected, which has all the cleanup code. So let that do
+                        // it.
+                        Log.w(TAG, "RemoteException during connect for " + mServiceComponent);
+                        if (DBG) {
+                            Log.d(TAG, "ServiceCallbacks.onConnect...");
+                            dump();
+                        }
+                    }
+                }
+            });
+        }
+
+        @Override
+        public void onServiceDisconnected(final ComponentName name) {
+            postOrRun(new Runnable() {
+                @Override
+                public void run() {
+                    if (DBG) {
+                        Log.d(TAG, "MediaServiceConnection.onServiceDisconnected name=" + name
+                                + " this=" + this + " mServiceConnection=" + mServiceConnection);
+                        dump();
+                    }
+
+                    // Make sure we are still the current connection, and that they haven't called
+                    // disconnect().
+                    if (!isCurrent("onServiceDisconnected")) {
+                        return;
+                    }
+
+                    // Clear out what we set in onServiceConnected
+                    mServiceBinder = null;
+                    mServiceCallbacks = null;
+
+                    // And tell the app that it's suspended.
+                    mState = CONNECT_STATE_SUSPENDED;
+                    mCallback.onConnectionSuspended();
+                }
+            });
+        }
+
+        private void postOrRun(Runnable r) {
+            if (Thread.currentThread() == mHandler.getLooper().getThread()) {
+                r.run();
+            } else {
+                mHandler.post(r);
+            }
+        }
+
+        /**
+         * Return true if this is the current ServiceConnection. Also logs if it's not.
+         */
+        private boolean isCurrent(String funcName) {
+            if (mServiceConnection != this || mState == CONNECT_STATE_DISCONNECTING
+                    || mState == CONNECT_STATE_DISCONNECTED) {
+                if (mState != CONNECT_STATE_DISCONNECTING && mState != CONNECT_STATE_DISCONNECTED) {
+                    // Check mState, because otherwise this log is noisy.
+                    Log.i(TAG, funcName + " for " + mServiceComponent + " with mServiceConnection="
+                            + mServiceConnection + " this=" + this);
+                }
+                return false;
+            }
+            return true;
+        }
+    }
+
+    /**
+     * Callbacks from the service.
+     */
+    private static class ServiceCallbacks extends IMediaBrowserServiceCallbacks.Stub {
+        private WeakReference<MediaBrowser> mMediaBrowser;
+
+        public ServiceCallbacks(MediaBrowser mediaBrowser) {
+            mMediaBrowser = new WeakReference<MediaBrowser>(mediaBrowser);
+        }
+
+        /**
+         * The other side has acknowledged our connection. The parameters to this function
+         * are the initial data as requested.
+         */
+        @Override
+        public void onConnect(String root, MediaSession.Token session,
+                final Bundle extras) {
+            MediaBrowser mediaBrowser = mMediaBrowser.get();
+            if (mediaBrowser != null) {
+                mediaBrowser.onServiceConnected(this, root, session, extras);
+            }
+        }
+
+        /**
+         * The other side does not like us. Tell the app via onConnectionFailed.
+         */
+        @Override
+        public void onConnectFailed() {
+            MediaBrowser mediaBrowser = mMediaBrowser.get();
+            if (mediaBrowser != null) {
+                mediaBrowser.onConnectionFailed(this);
+            }
+        }
+
+        @Override
+        public void onLoadChildren(String parentId, ParceledListSlice list) {
+            onLoadChildrenWithOptions(parentId, list, null);
+        }
+
+        @Override
+        public void onLoadChildrenWithOptions(String parentId, ParceledListSlice list,
+                final Bundle options) {
+            MediaBrowser mediaBrowser = mMediaBrowser.get();
+            if (mediaBrowser != null) {
+                mediaBrowser.onLoadChildren(this, parentId, list, options);
+            }
+        }
+    }
+
+    private static class Subscription {
+        private final List<SubscriptionCallback> mCallbacks;
+        private final List<Bundle> mOptionsList;
+
+        public Subscription() {
+            mCallbacks = new ArrayList<>();
+            mOptionsList = new ArrayList<>();
+        }
+
+        public boolean isEmpty() {
+            return mCallbacks.isEmpty();
+        }
+
+        public List<Bundle> getOptionsList() {
+            return mOptionsList;
+        }
+
+        public List<SubscriptionCallback> getCallbacks() {
+            return mCallbacks;
+        }
+
+        public SubscriptionCallback getCallback(Context context, Bundle options) {
+            if (options != null) {
+                options.setClassLoader(context.getClassLoader());
+            }
+            for (int i = 0; i < mOptionsList.size(); ++i) {
+                if (MediaBrowserUtils.areSameOptions(mOptionsList.get(i), options)) {
+                    return mCallbacks.get(i);
+                }
+            }
+            return null;
+        }
+
+        public void putCallback(Context context, Bundle options, SubscriptionCallback callback) {
+            if (options != null) {
+                options.setClassLoader(context.getClassLoader());
+            }
+            for (int i = 0; i < mOptionsList.size(); ++i) {
+                if (MediaBrowserUtils.areSameOptions(mOptionsList.get(i), options)) {
+                    mCallbacks.set(i, callback);
+                    return;
+                }
+            }
+            mCallbacks.add(callback);
+            mOptionsList.add(options);
+        }
+    }
+}
diff --git a/packages/MediaComponents/apex/java/android/media/browse/MediaBrowserUtils.java b/packages/MediaComponents/apex/java/android/media/browse/MediaBrowserUtils.java
new file mode 100644
index 0000000..2943e60
--- /dev/null
+++ b/packages/MediaComponents/apex/java/android/media/browse/MediaBrowserUtils.java
@@ -0,0 +1,72 @@
+/*
+ * Copyright (C) 2016 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package android.media.browse;
+
+import android.os.Bundle;
+
+/**
+ * @hide
+ */
+public class MediaBrowserUtils {
+    public static boolean areSameOptions(Bundle options1, Bundle options2) {
+        if (options1 == options2) {
+            return true;
+        } else if (options1 == null) {
+            return options2.getInt(MediaBrowser.EXTRA_PAGE, -1) == -1
+                    && options2.getInt(MediaBrowser.EXTRA_PAGE_SIZE, -1) == -1;
+        } else if (options2 == null) {
+            return options1.getInt(MediaBrowser.EXTRA_PAGE, -1) == -1
+                    && options1.getInt(MediaBrowser.EXTRA_PAGE_SIZE, -1) == -1;
+        } else {
+            return options1.getInt(MediaBrowser.EXTRA_PAGE, -1)
+                    == options2.getInt(MediaBrowser.EXTRA_PAGE, -1)
+                    && options1.getInt(MediaBrowser.EXTRA_PAGE_SIZE, -1)
+                    == options2.getInt(MediaBrowser.EXTRA_PAGE_SIZE, -1);
+        }
+    }
+
+    public static boolean hasDuplicatedItems(Bundle options1, Bundle options2) {
+        int page1 = options1 == null ? -1 : options1.getInt(MediaBrowser.EXTRA_PAGE, -1);
+        int page2 = options2 == null ? -1 : options2.getInt(MediaBrowser.EXTRA_PAGE, -1);
+        int pageSize1 = options1 == null ? -1 : options1.getInt(MediaBrowser.EXTRA_PAGE_SIZE, -1);
+        int pageSize2 = options2 == null ? -1 : options2.getInt(MediaBrowser.EXTRA_PAGE_SIZE, -1);
+
+        int startIndex1, startIndex2, endIndex1, endIndex2;
+        if (page1 == -1 || pageSize1 == -1) {
+            startIndex1 = 0;
+            endIndex1 = Integer.MAX_VALUE;
+        } else {
+            startIndex1 = pageSize1 * page1;
+            endIndex1 = startIndex1 + pageSize1 - 1;
+        }
+
+        if (page2 == -1 || pageSize2 == -1) {
+            startIndex2 = 0;
+            endIndex2 = Integer.MAX_VALUE;
+        } else {
+            startIndex2 = pageSize2 * page2;
+            endIndex2 = startIndex2 + pageSize2 - 1;
+        }
+
+        if (startIndex1 <= startIndex2 && startIndex2 <= endIndex1) {
+            return true;
+        } else if (startIndex1 <= endIndex2 && endIndex2 <= endIndex1) {
+            return true;
+        }
+        return false;
+    }
+}
diff --git a/packages/MediaComponents/apex/java/android/media/session/IActiveSessionsListener.aidl b/packages/MediaComponents/apex/java/android/media/session/IActiveSessionsListener.aidl
new file mode 100644
index 0000000..4b9e4bd
--- /dev/null
+++ b/packages/MediaComponents/apex/java/android/media/session/IActiveSessionsListener.aidl
@@ -0,0 +1,26 @@
+/* Copyright (C) 2014 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package android.media.session;
+
+import android.media.session.MediaSession;
+
+/**
+ * Listens for changes to the list of active sessions.
+ * @hide
+ */
+oneway interface IActiveSessionsListener {
+    void onActiveSessionsChanged(in List<MediaSession.Token> sessions);
+}
diff --git a/packages/MediaComponents/apex/java/android/media/session/ICallback.aidl b/packages/MediaComponents/apex/java/android/media/session/ICallback.aidl
new file mode 100644
index 0000000..322bffa
--- /dev/null
+++ b/packages/MediaComponents/apex/java/android/media/session/ICallback.aidl
@@ -0,0 +1,35 @@
+/* Copyright (C) 2016 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package android.media.session;
+
+import android.app.PendingIntent;
+import android.content.ComponentName;
+import android.media.session.MediaSession;
+import android.view.KeyEvent;
+
+/**
+ * @hide
+ */
+oneway interface ICallback {
+    void onMediaKeyEventDispatchedToMediaSession(in KeyEvent event,
+            in MediaSession.Token sessionToken);
+    void onMediaKeyEventDispatchedToMediaButtonReceiver(in KeyEvent event,
+            in ComponentName mediaButtonReceiver);
+
+    void onAddressedPlayerChangedToMediaSession(in MediaSession.Token sessionToken);
+    void onAddressedPlayerChangedToMediaButtonReceiver(in ComponentName mediaButtonReceiver);
+}
+
diff --git a/packages/MediaComponents/apex/java/android/media/session/IOnMediaKeyListener.aidl b/packages/MediaComponents/apex/java/android/media/session/IOnMediaKeyListener.aidl
new file mode 100644
index 0000000..aa98ea3
--- /dev/null
+++ b/packages/MediaComponents/apex/java/android/media/session/IOnMediaKeyListener.aidl
@@ -0,0 +1,28 @@
+/* Copyright (C) 2016 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package android.media.session;
+
+import android.os.ResultReceiver;
+import android.view.KeyEvent;
+
+/**
+ * Listener to handle media key.
+ * @hide
+ */
+oneway interface IOnMediaKeyListener {
+    void onMediaKey(in KeyEvent event, in ResultReceiver result);
+}
+
diff --git a/packages/MediaComponents/apex/java/android/media/session/IOnVolumeKeyLongPressListener.aidl b/packages/MediaComponents/apex/java/android/media/session/IOnVolumeKeyLongPressListener.aidl
new file mode 100644
index 0000000..07b8347
--- /dev/null
+++ b/packages/MediaComponents/apex/java/android/media/session/IOnVolumeKeyLongPressListener.aidl
@@ -0,0 +1,27 @@
+/* Copyright (C) 2016 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package android.media.session;
+
+import android.view.KeyEvent;
+
+/**
+ * Listener to handle volume key long-press.
+ * @hide
+ */
+oneway interface IOnVolumeKeyLongPressListener {
+    void onVolumeKeyLongPress(in KeyEvent event);
+}
+
diff --git a/packages/MediaComponents/apex/java/android/media/session/ISession.aidl b/packages/MediaComponents/apex/java/android/media/session/ISession.aidl
new file mode 100644
index 0000000..bd0019f
--- /dev/null
+++ b/packages/MediaComponents/apex/java/android/media/session/ISession.aidl
@@ -0,0 +1,53 @@
+/* Copyright (C) 2014 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package android.media.session;
+
+import android.app.PendingIntent;
+import android.content.pm.ParceledListSlice;
+import android.media.AudioAttributes;
+import android.media.MediaMetadata;
+import android.media.session.ISessionController;
+import android.media.session.PlaybackState;
+import android.media.session.MediaSession;
+import android.os.Bundle;
+import android.os.ResultReceiver;
+
+/**
+ * Interface to a MediaSession in the system.
+ * @hide
+ */
+interface ISession {
+    void sendEvent(String event, in Bundle data);
+    ISessionController getController();
+    void setFlags(int flags);
+    void setActive(boolean active);
+    void setMediaButtonReceiver(in PendingIntent mbr);
+    void setLaunchPendingIntent(in PendingIntent pi);
+    void destroy();
+
+    // These commands are for the TransportPerformer
+    void setMetadata(in MediaMetadata metadata);
+    void setPlaybackState(in PlaybackState state);
+    void setQueue(in ParceledListSlice queue);
+    void setQueueTitle(CharSequence title);
+    void setExtras(in Bundle extras);
+    void setRatingType(int type);
+
+    // These commands relate to volume handling
+    void setPlaybackToLocal(in AudioAttributes attributes);
+    void setPlaybackToRemote(int control, int max);
+    void setCurrentVolume(int currentVolume);
+}
diff --git a/packages/MediaComponents/apex/java/android/media/session/ISessionCallback.aidl b/packages/MediaComponents/apex/java/android/media/session/ISessionCallback.aidl
new file mode 100644
index 0000000..626338d
--- /dev/null
+++ b/packages/MediaComponents/apex/java/android/media/session/ISessionCallback.aidl
@@ -0,0 +1,71 @@
+/* Copyright (C) 2014 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package android.media.session;
+
+import android.content.Intent;
+import android.media.Rating;
+import android.media.session.ISessionControllerCallback;
+import android.net.Uri;
+import android.os.Bundle;
+import android.os.ResultReceiver;
+
+/**
+ * @hide
+ */
+oneway interface ISessionCallback {
+    void onCommand(String packageName, int pid, int uid, ISessionControllerCallback caller,
+            String command, in Bundle args, in ResultReceiver cb);
+    void onMediaButton(String packageName, int pid, int uid, in Intent mediaButtonIntent,
+            int sequenceNumber, in ResultReceiver cb);
+    void onMediaButtonFromController(String packageName, int pid, int uid,
+            ISessionControllerCallback caller, in Intent mediaButtonIntent);
+
+    // These callbacks are for the TransportPerformer
+    void onPrepare(String packageName, int pid, int uid, ISessionControllerCallback caller);
+    void onPrepareFromMediaId(String packageName, int pid, int uid,
+            ISessionControllerCallback caller, String mediaId, in Bundle extras);
+    void onPrepareFromSearch(String packageName, int pid, int uid,
+            ISessionControllerCallback caller, String query, in Bundle extras);
+    void onPrepareFromUri(String packageName, int pid, int uid, ISessionControllerCallback caller,
+            in Uri uri, in Bundle extras);
+    void onPlay(String packageName, int pid, int uid, ISessionControllerCallback caller);
+    void onPlayFromMediaId(String packageName, int pid, int uid, ISessionControllerCallback caller,
+            String mediaId, in Bundle extras);
+    void onPlayFromSearch(String packageName, int pid, int uid, ISessionControllerCallback caller,
+            String query, in Bundle extras);
+    void onPlayFromUri(String packageName, int pid, int uid, ISessionControllerCallback caller,
+            in Uri uri, in Bundle extras);
+    void onSkipToTrack(String packageName, int pid, int uid, ISessionControllerCallback caller,
+            long id);
+    void onPause(String packageName, int pid, int uid, ISessionControllerCallback caller);
+    void onStop(String packageName, int pid, int uid, ISessionControllerCallback caller);
+    void onNext(String packageName, int pid, int uid, ISessionControllerCallback caller);
+    void onPrevious(String packageName, int pid, int uid, ISessionControllerCallback caller);
+    void onFastForward(String packageName, int pid, int uid, ISessionControllerCallback caller);
+    void onRewind(String packageName, int pid, int uid, ISessionControllerCallback caller);
+    void onSeekTo(String packageName, int pid, int uid, ISessionControllerCallback caller,
+            long pos);
+    void onRate(String packageName, int pid, int uid, ISessionControllerCallback caller,
+            in Rating rating);
+    void onCustomAction(String packageName, int pid, int uid, ISessionControllerCallback caller,
+            String action, in Bundle args);
+
+    // These callbacks are for volume handling
+    void onAdjustVolume(String packageName, int pid, int uid, ISessionControllerCallback caller,
+            int direction);
+    void onSetVolumeTo(String packageName, int pid, int uid,
+            ISessionControllerCallback caller, int value);
+}
diff --git a/packages/MediaComponents/apex/java/android/media/session/ISessionController.aidl b/packages/MediaComponents/apex/java/android/media/session/ISessionController.aidl
new file mode 100644
index 0000000..861a8ce
--- /dev/null
+++ b/packages/MediaComponents/apex/java/android/media/session/ISessionController.aidl
@@ -0,0 +1,88 @@
+/* Copyright (C) 2014 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package android.media.session;
+
+import android.app.PendingIntent;
+import android.content.Intent;
+import android.content.pm.ParceledListSlice;
+import android.media.MediaMetadata;
+import android.media.Rating;
+import android.media.session.ISessionControllerCallback;
+import android.media.session.MediaSession;
+import android.media.session.ParcelableVolumeInfo;
+import android.media.session.PlaybackState;
+import android.net.Uri;
+import android.os.Bundle;
+import android.os.ResultReceiver;
+import android.view.KeyEvent;
+
+import java.util.List;
+
+/**
+ * Interface to MediaSessionRecord in the system.
+ * @hide
+ */
+interface ISessionController {
+    void sendCommand(String packageName, ISessionControllerCallback caller,
+            String command, in Bundle args, in ResultReceiver cb);
+    boolean sendMediaButton(String packageName, ISessionControllerCallback caller,
+            boolean asSystemService, in KeyEvent mediaButton);
+    void registerCallbackListener(String packageName, ISessionControllerCallback cb);
+    void unregisterCallbackListener(ISessionControllerCallback cb);
+    boolean isTransportControlEnabled();
+    String getPackageName();
+    String getTag();
+    PendingIntent getLaunchPendingIntent();
+    long getFlags();
+    ParcelableVolumeInfo getVolumeAttributes();
+    void adjustVolume(String packageName, ISessionControllerCallback caller,
+            boolean asSystemService, int direction, int flags);
+    void setVolumeTo(String packageName, ISessionControllerCallback caller,
+            int value, int flags);
+
+    // These commands are for the TransportControls
+    void prepare(String packageName, ISessionControllerCallback caller);
+    void prepareFromMediaId(String packageName, ISessionControllerCallback caller,
+            String mediaId, in Bundle extras);
+    void prepareFromSearch(String packageName, ISessionControllerCallback caller,
+            String string, in Bundle extras);
+    void prepareFromUri(String packageName, ISessionControllerCallback caller,
+            in Uri uri, in Bundle extras);
+    void play(String packageName, ISessionControllerCallback caller);
+    void playFromMediaId(String packageName, ISessionControllerCallback caller,
+            String mediaId, in Bundle extras);
+    void playFromSearch(String packageName, ISessionControllerCallback caller,
+            String string, in Bundle extras);
+    void playFromUri(String packageName, ISessionControllerCallback caller,
+            in Uri uri, in Bundle extras);
+    void skipToQueueItem(String packageName, ISessionControllerCallback caller, long id);
+    void pause(String packageName, ISessionControllerCallback caller);
+    void stop(String packageName, ISessionControllerCallback caller);
+    void next(String packageName, ISessionControllerCallback caller);
+    void previous(String packageName, ISessionControllerCallback caller);
+    void fastForward(String packageName, ISessionControllerCallback caller);
+    void rewind(String packageName, ISessionControllerCallback caller);
+    void seekTo(String packageName, ISessionControllerCallback caller, long pos);
+    void rate(String packageName, ISessionControllerCallback caller, in Rating rating);
+    void sendCustomAction(String packageName, ISessionControllerCallback caller,
+            String action, in Bundle args);
+    MediaMetadata getMetadata();
+    PlaybackState getPlaybackState();
+    ParceledListSlice getQueue();
+    CharSequence getQueueTitle();
+    Bundle getExtras();
+    int getRatingType();
+}
diff --git a/packages/MediaComponents/apex/java/android/media/session/ISessionControllerCallback.aidl b/packages/MediaComponents/apex/java/android/media/session/ISessionControllerCallback.aidl
new file mode 100644
index 0000000..cf31767
--- /dev/null
+++ b/packages/MediaComponents/apex/java/android/media/session/ISessionControllerCallback.aidl
@@ -0,0 +1,39 @@
+/* Copyright (C) 2014 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package android.media.session;
+
+import android.content.pm.ParceledListSlice;
+import android.media.MediaMetadata;
+import android.media.session.ParcelableVolumeInfo;
+import android.media.session.PlaybackState;
+import android.media.session.MediaSession;
+import android.os.Bundle;
+
+/**
+ * @hide
+ */
+oneway interface ISessionControllerCallback {
+    void onEvent(String event, in Bundle extras);
+    void onSessionDestroyed();
+
+    // These callbacks are for the TransportController
+    void onPlaybackStateChanged(in PlaybackState state);
+    void onMetadataChanged(in MediaMetadata metadata);
+    void onQueueChanged(in ParceledListSlice queue);
+    void onQueueTitleChanged(CharSequence title);
+    void onExtrasChanged(in Bundle extras);
+    void onVolumeInfoChanged(in ParcelableVolumeInfo info);
+}
diff --git a/packages/MediaComponents/apex/java/android/media/session/ISessionManager.aidl b/packages/MediaComponents/apex/java/android/media/session/ISessionManager.aidl
new file mode 100644
index 0000000..3578c16
--- /dev/null
+++ b/packages/MediaComponents/apex/java/android/media/session/ISessionManager.aidl
@@ -0,0 +1,66 @@
+/* Copyright (C) 2014 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package android.media.session;
+
+import android.content.ComponentName;
+import android.media.IRemoteVolumeController;
+import android.media.ISessionTokensListener;
+import android.media.session.IActiveSessionsListener;
+import android.media.session.ICallback;
+import android.media.session.IOnMediaKeyListener;
+import android.media.session.IOnVolumeKeyLongPressListener;
+import android.media.session.ISession;
+import android.media.session.ISessionCallback;
+import android.os.Bundle;
+import android.view.KeyEvent;
+
+/**
+ * Interface to the MediaSessionManagerService
+ * @hide
+ */
+interface ISessionManager {
+    ISession createSession(String packageName, in ISessionCallback cb, String tag, int userId);
+    List<IBinder> getSessions(in ComponentName compName, int userId);
+    void dispatchMediaKeyEvent(String packageName, boolean asSystemService, in KeyEvent keyEvent,
+            boolean needWakeLock);
+    void dispatchVolumeKeyEvent(String packageName, boolean asSystemService, in KeyEvent keyEvent,
+            int stream, boolean musicOnly);
+    void dispatchAdjustVolume(String packageName, int suggestedStream, int delta, int flags);
+    void addSessionsListener(in IActiveSessionsListener listener, in ComponentName compName,
+            int userId);
+    void removeSessionsListener(in IActiveSessionsListener listener);
+
+    // This is for the system volume UI only
+    void setRemoteVolumeController(in IRemoteVolumeController rvc);
+
+    // For PhoneWindowManager to precheck media keys
+    boolean isGlobalPriorityActive();
+
+    void setCallback(in ICallback callback);
+    void setOnVolumeKeyLongPressListener(in IOnVolumeKeyLongPressListener listener);
+    void setOnMediaKeyListener(in IOnMediaKeyListener listener);
+
+    // MediaSession2
+    boolean isTrusted(String controllerPackageName, int controllerPid, int controllerUid);
+    boolean createSession2(in Bundle sessionToken);
+    void destroySession2(in Bundle sessionToken);
+    List<Bundle> getSessionTokens(boolean activeSessionOnly, boolean sessionServiceOnly,
+            String packageName);
+
+    void addSessionTokensListener(in ISessionTokensListener listener, int userId,
+            String packageName);
+    void removeSessionTokensListener(in ISessionTokensListener listener, String packageName);
+}
diff --git a/packages/MediaComponents/apex/java/android/media/session/MediaController.java b/packages/MediaComponents/apex/java/android/media/session/MediaController.java
new file mode 100644
index 0000000..c4b82c3
--- /dev/null
+++ b/packages/MediaComponents/apex/java/android/media/session/MediaController.java
@@ -0,0 +1,1187 @@
+/*
+ * Copyright (C) 2014 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package android.media.session;
+
+import android.annotation.NonNull;
+import android.annotation.Nullable;
+import android.annotation.UnsupportedAppUsage;
+import android.app.PendingIntent;
+import android.content.Context;
+import android.content.pm.ParceledListSlice;
+import android.media.AudioAttributes;
+import android.media.AudioManager;
+import android.media.MediaMetadata;
+import android.media.Rating;
+import android.media.VolumeProvider;
+import android.net.Uri;
+import android.os.Bundle;
+import android.os.Handler;
+import android.os.Looper;
+import android.os.Message;
+import android.os.RemoteException;
+import android.os.ResultReceiver;
+import android.text.TextUtils;
+import android.util.Log;
+import android.view.KeyEvent;
+
+import java.lang.ref.WeakReference;
+import java.util.ArrayList;
+import java.util.List;
+
+/**
+ * Allows an app to interact with an ongoing media session. Media buttons and
+ * other commands can be sent to the session. A callback may be registered to
+ * receive updates from the session, such as metadata and play state changes.
+ * <p>
+ * A MediaController can be created through {@link MediaSessionManager} if you
+ * hold the "android.permission.MEDIA_CONTENT_CONTROL" permission or are an
+ * enabled notification listener or by getting a {@link MediaSession.Token}
+ * directly from the session owner.
+ * <p>
+ * MediaController objects are thread-safe.
+ */
+public final class MediaController {
+    private static final String TAG = "MediaController";
+
+    private static final int MSG_EVENT = 1;
+    private static final int MSG_UPDATE_PLAYBACK_STATE = 2;
+    private static final int MSG_UPDATE_METADATA = 3;
+    private static final int MSG_UPDATE_VOLUME = 4;
+    private static final int MSG_UPDATE_QUEUE = 5;
+    private static final int MSG_UPDATE_QUEUE_TITLE = 6;
+    private static final int MSG_UPDATE_EXTRAS = 7;
+    private static final int MSG_DESTROYED = 8;
+
+    private final ISessionController mSessionBinder;
+
+    private final MediaSession.Token mToken;
+    private final Context mContext;
+    private final CallbackStub mCbStub = new CallbackStub(this);
+    private final ArrayList<MessageHandler> mCallbacks = new ArrayList<MessageHandler>();
+    private final Object mLock = new Object();
+
+    private boolean mCbRegistered = false;
+    private String mPackageName;
+    private String mTag;
+
+    private final TransportControls mTransportControls;
+
+    /**
+     * Call for creating a MediaController directly from a binder. Should only
+     * be used by framework code.
+     *
+     * @hide
+     */
+    public MediaController(Context context, ISessionController sessionBinder) {
+        if (sessionBinder == null) {
+            throw new IllegalArgumentException("Session token cannot be null");
+        }
+        if (context == null) {
+            throw new IllegalArgumentException("Context cannot be null");
+        }
+        mSessionBinder = sessionBinder;
+        mTransportControls = new TransportControls();
+        mToken = new MediaSession.Token(sessionBinder);
+        mContext = context;
+    }
+
+    /**
+     * Create a new MediaController from a session's token.
+     *
+     * @param context The caller's context.
+     * @param token The token for the session.
+     */
+    public MediaController(@NonNull Context context, @NonNull MediaSession.Token token) {
+        this(context, token.getBinder());
+    }
+
+    /**
+     * Get a {@link TransportControls} instance to send transport actions to
+     * the associated session.
+     *
+     * @return A transport controls instance.
+     */
+    public @NonNull TransportControls getTransportControls() {
+        return mTransportControls;
+    }
+
+    /**
+     * Send the specified media button event to the session. Only media keys can
+     * be sent by this method, other keys will be ignored.
+     *
+     * @param keyEvent The media button event to dispatch.
+     * @return true if the event was sent to the session, false otherwise.
+     */
+    public boolean dispatchMediaButtonEvent(@NonNull KeyEvent keyEvent) {
+        return dispatchMediaButtonEventInternal(false, keyEvent);
+    }
+
+    /**
+     * Dispatches the media button event as system service to the session.
+     * <p>
+     * Should be only called by the {@link com.android.internal.policy.PhoneWindow} when the
+     * foreground activity didn't consume the key from the hardware devices.
+     *
+     * @param keyEvent media key event
+     * @return {@code true} if the event was sent to the session, {@code false} otherwise
+     * @hide
+     */
+    public boolean dispatchMediaButtonEventAsSystemService(@NonNull KeyEvent keyEvent) {
+        return dispatchMediaButtonEventInternal(true, keyEvent);
+    }
+
+    private boolean dispatchMediaButtonEventInternal(boolean asSystemService,
+            @NonNull KeyEvent keyEvent) {
+        if (keyEvent == null) {
+            throw new IllegalArgumentException("KeyEvent may not be null");
+        }
+        if (!KeyEvent.isMediaKey(keyEvent.getKeyCode())) {
+            return false;
+        }
+        try {
+            return mSessionBinder.sendMediaButton(mContext.getOpPackageName(), mCbStub,
+                    asSystemService, keyEvent);
+        } catch (RemoteException e) {
+            // System is dead. =(
+        }
+        return false;
+    }
+
+    /**
+     * Dispatches the volume button event as system service to the session.
+     * <p>
+     * Should be only called by the {@link com.android.internal.policy.PhoneWindow} when the
+     * foreground activity didn't consume the key from the hardware devices.
+     *
+     * @param keyEvent volume key event
+     * @hide
+     */
+    public void dispatchVolumeButtonEventAsSystemService(@NonNull KeyEvent keyEvent) {
+        switch (keyEvent.getAction()) {
+            case KeyEvent.ACTION_DOWN: {
+                int direction = 0;
+                switch (keyEvent.getKeyCode()) {
+                    case KeyEvent.KEYCODE_VOLUME_UP:
+                        direction = AudioManager.ADJUST_RAISE;
+                        break;
+                    case KeyEvent.KEYCODE_VOLUME_DOWN:
+                        direction = AudioManager.ADJUST_LOWER;
+                        break;
+                    case KeyEvent.KEYCODE_VOLUME_MUTE:
+                        direction = AudioManager.ADJUST_TOGGLE_MUTE;
+                        break;
+                }
+                try {
+                    mSessionBinder.adjustVolume(mContext.getOpPackageName(), mCbStub, true,
+                            direction, AudioManager.FLAG_SHOW_UI);
+                } catch (RemoteException e) {
+                    Log.wtf(TAG, "Error calling adjustVolumeBy", e);
+                }
+            }
+
+            case KeyEvent.ACTION_UP: {
+                final int flags = AudioManager.FLAG_PLAY_SOUND | AudioManager.FLAG_VIBRATE
+                        | AudioManager.FLAG_FROM_KEY;
+                try {
+                    mSessionBinder.adjustVolume(mContext.getOpPackageName(), mCbStub, true, 0,
+                            flags);
+                } catch (RemoteException e) {
+                    Log.wtf(TAG, "Error calling adjustVolumeBy", e);
+                }
+            }
+        }
+    }
+
+    /**
+     * Get the current playback state for this session.
+     *
+     * @return The current PlaybackState or null
+     */
+    public @Nullable PlaybackState getPlaybackState() {
+        try {
+            return mSessionBinder.getPlaybackState();
+        } catch (RemoteException e) {
+            Log.wtf(TAG, "Error calling getPlaybackState.", e);
+            return null;
+        }
+    }
+
+    /**
+     * Get the current metadata for this session.
+     *
+     * @return The current MediaMetadata or null.
+     */
+    public @Nullable MediaMetadata getMetadata() {
+        try {
+            return mSessionBinder.getMetadata();
+        } catch (RemoteException e) {
+            Log.wtf(TAG, "Error calling getMetadata.", e);
+            return null;
+        }
+    }
+
+    /**
+     * Get the current play queue for this session if one is set. If you only
+     * care about the current item {@link #getMetadata()} should be used.
+     *
+     * @return The current play queue or null.
+     */
+    public @Nullable List<MediaSession.QueueItem> getQueue() {
+        try {
+            ParceledListSlice queue = mSessionBinder.getQueue();
+            if (queue != null) {
+                return queue.getList();
+            }
+        } catch (RemoteException e) {
+            Log.wtf(TAG, "Error calling getQueue.", e);
+        }
+        return null;
+    }
+
+    /**
+     * Get the queue title for this session.
+     */
+    public @Nullable CharSequence getQueueTitle() {
+        try {
+            return mSessionBinder.getQueueTitle();
+        } catch (RemoteException e) {
+            Log.wtf(TAG, "Error calling getQueueTitle", e);
+        }
+        return null;
+    }
+
+    /**
+     * Get the extras for this session.
+     */
+    public @Nullable Bundle getExtras() {
+        try {
+            return mSessionBinder.getExtras();
+        } catch (RemoteException e) {
+            Log.wtf(TAG, "Error calling getExtras", e);
+        }
+        return null;
+    }
+
+    /**
+     * Get the rating type supported by the session. One of:
+     * <ul>
+     * <li>{@link Rating#RATING_NONE}</li>
+     * <li>{@link Rating#RATING_HEART}</li>
+     * <li>{@link Rating#RATING_THUMB_UP_DOWN}</li>
+     * <li>{@link Rating#RATING_3_STARS}</li>
+     * <li>{@link Rating#RATING_4_STARS}</li>
+     * <li>{@link Rating#RATING_5_STARS}</li>
+     * <li>{@link Rating#RATING_PERCENTAGE}</li>
+     * </ul>
+     *
+     * @return The supported rating type
+     */
+    public int getRatingType() {
+        try {
+            return mSessionBinder.getRatingType();
+        } catch (RemoteException e) {
+            Log.wtf(TAG, "Error calling getRatingType.", e);
+            return Rating.RATING_NONE;
+        }
+    }
+
+    /**
+     * Get the flags for this session. Flags are defined in {@link MediaSession}.
+     *
+     * @return The current set of flags for the session.
+     */
+    public @MediaSession.SessionFlags long getFlags() {
+        try {
+            return mSessionBinder.getFlags();
+        } catch (RemoteException e) {
+            Log.wtf(TAG, "Error calling getFlags.", e);
+        }
+        return 0;
+    }
+
+    /**
+     * Get the current playback info for this session.
+     *
+     * @return The current playback info or null.
+     */
+    public @Nullable PlaybackInfo getPlaybackInfo() {
+        try {
+            ParcelableVolumeInfo result = mSessionBinder.getVolumeAttributes();
+            return new PlaybackInfo(result.volumeType, result.audioAttrs, result.controlType,
+                    result.maxVolume, result.currentVolume);
+
+        } catch (RemoteException e) {
+            Log.wtf(TAG, "Error calling getAudioInfo.", e);
+        }
+        return null;
+    }
+
+    /**
+     * Get an intent for launching UI associated with this session if one
+     * exists.
+     *
+     * @return A {@link PendingIntent} to launch UI or null.
+     */
+    public @Nullable PendingIntent getSessionActivity() {
+        try {
+            return mSessionBinder.getLaunchPendingIntent();
+        } catch (RemoteException e) {
+            Log.wtf(TAG, "Error calling getPendingIntent.", e);
+        }
+        return null;
+    }
+
+    /**
+     * Get the token for the session this is connected to.
+     *
+     * @return The token for the connected session.
+     */
+    public @NonNull MediaSession.Token getSessionToken() {
+        return mToken;
+    }
+
+    /**
+     * Set the volume of the output this session is playing on. The command will
+     * be ignored if it does not support
+     * {@link VolumeProvider#VOLUME_CONTROL_ABSOLUTE}. The flags in
+     * {@link AudioManager} may be used to affect the handling.
+     *
+     * @see #getPlaybackInfo()
+     * @param value The value to set it to, between 0 and the reported max.
+     * @param flags Flags from {@link AudioManager} to include with the volume
+     *            request.
+     */
+    public void setVolumeTo(int value, int flags) {
+        try {
+            mSessionBinder.setVolumeTo(mContext.getOpPackageName(), mCbStub, value, flags);
+        } catch (RemoteException e) {
+            Log.wtf(TAG, "Error calling setVolumeTo.", e);
+        }
+    }
+
+    /**
+     * Adjust the volume of the output this session is playing on. The direction
+     * must be one of {@link AudioManager#ADJUST_LOWER},
+     * {@link AudioManager#ADJUST_RAISE}, or {@link AudioManager#ADJUST_SAME}.
+     * The command will be ignored if the session does not support
+     * {@link VolumeProvider#VOLUME_CONTROL_RELATIVE} or
+     * {@link VolumeProvider#VOLUME_CONTROL_ABSOLUTE}. The flags in
+     * {@link AudioManager} may be used to affect the handling.
+     *
+     * @see #getPlaybackInfo()
+     * @param direction The direction to adjust the volume in.
+     * @param flags Any flags to pass with the command.
+     */
+    public void adjustVolume(int direction, int flags) {
+        try {
+            mSessionBinder.adjustVolume(mContext.getOpPackageName(), mCbStub, false, direction,
+                    flags);
+        } catch (RemoteException e) {
+            Log.wtf(TAG, "Error calling adjustVolumeBy.", e);
+        }
+    }
+
+    /**
+     * Registers a callback to receive updates from the Session. Updates will be
+     * posted on the caller's thread.
+     *
+     * @param callback The callback object, must not be null.
+     */
+    public void registerCallback(@NonNull Callback callback) {
+        registerCallback(callback, null);
+    }
+
+    /**
+     * Registers a callback to receive updates from the session. Updates will be
+     * posted on the specified handler's thread.
+     *
+     * @param callback The callback object, must not be null.
+     * @param handler The handler to post updates on. If null the callers thread
+     *            will be used.
+     */
+    public void registerCallback(@NonNull Callback callback, @Nullable Handler handler) {
+        if (callback == null) {
+            throw new IllegalArgumentException("callback must not be null");
+        }
+        if (handler == null) {
+            handler = new Handler();
+        }
+        synchronized (mLock) {
+            addCallbackLocked(callback, handler);
+        }
+    }
+
+    /**
+     * Unregisters the specified callback. If an update has already been posted
+     * you may still receive it after calling this method.
+     *
+     * @param callback The callback to remove.
+     */
+    public void unregisterCallback(@NonNull Callback callback) {
+        if (callback == null) {
+            throw new IllegalArgumentException("callback must not be null");
+        }
+        synchronized (mLock) {
+            removeCallbackLocked(callback);
+        }
+    }
+
+    /**
+     * Sends a generic command to the session. It is up to the session creator
+     * to decide what commands and parameters they will support. As such,
+     * commands should only be sent to sessions that the controller owns.
+     *
+     * @param command The command to send
+     * @param args Any parameters to include with the command
+     * @param cb The callback to receive the result on
+     */
+    public void sendCommand(@NonNull String command, @Nullable Bundle args,
+            @Nullable ResultReceiver cb) {
+        if (TextUtils.isEmpty(command)) {
+            throw new IllegalArgumentException("command cannot be null or empty");
+        }
+        try {
+            mSessionBinder.sendCommand(mContext.getOpPackageName(), mCbStub, command, args, cb);
+        } catch (RemoteException e) {
+            Log.d(TAG, "Dead object in sendCommand.", e);
+        }
+    }
+
+    /**
+     * Get the session owner's package name.
+     *
+     * @return The package name of of the session owner.
+     */
+    public String getPackageName() {
+        if (mPackageName == null) {
+            try {
+                mPackageName = mSessionBinder.getPackageName();
+            } catch (RemoteException e) {
+                Log.d(TAG, "Dead object in getPackageName.", e);
+            }
+        }
+        return mPackageName;
+    }
+
+    /**
+     * Get the session's tag for debugging purposes.
+     *
+     * @return The session's tag.
+     * @hide
+     */
+    public String getTag() {
+        if (mTag == null) {
+            try {
+                mTag = mSessionBinder.getTag();
+            } catch (RemoteException e) {
+                Log.d(TAG, "Dead object in getTag.", e);
+            }
+        }
+        return mTag;
+    }
+
+    /*
+     * @hide
+     */
+    ISessionController getSessionBinder() {
+        return mSessionBinder;
+    }
+
+    /**
+     * @hide
+     */
+    @UnsupportedAppUsage
+    public boolean controlsSameSession(MediaController other) {
+        if (other == null) return false;
+        return mSessionBinder.asBinder() == other.getSessionBinder().asBinder();
+    }
+
+    private void addCallbackLocked(Callback cb, Handler handler) {
+        if (getHandlerForCallbackLocked(cb) != null) {
+            Log.w(TAG, "Callback is already added, ignoring");
+            return;
+        }
+        MessageHandler holder = new MessageHandler(handler.getLooper(), cb);
+        mCallbacks.add(holder);
+        holder.mRegistered = true;
+
+        if (!mCbRegistered) {
+            try {
+                mSessionBinder.registerCallbackListener(mContext.getOpPackageName(), mCbStub);
+                mCbRegistered = true;
+            } catch (RemoteException e) {
+                Log.e(TAG, "Dead object in registerCallback", e);
+            }
+        }
+    }
+
+    private boolean removeCallbackLocked(Callback cb) {
+        boolean success = false;
+        for (int i = mCallbacks.size() - 1; i >= 0; i--) {
+            MessageHandler handler = mCallbacks.get(i);
+            if (cb == handler.mCallback) {
+                mCallbacks.remove(i);
+                success = true;
+                handler.mRegistered = false;
+            }
+        }
+        if (mCbRegistered && mCallbacks.size() == 0) {
+            try {
+                mSessionBinder.unregisterCallbackListener(mCbStub);
+            } catch (RemoteException e) {
+                Log.e(TAG, "Dead object in removeCallbackLocked");
+            }
+            mCbRegistered = false;
+        }
+        return success;
+    }
+
+    private MessageHandler getHandlerForCallbackLocked(Callback cb) {
+        if (cb == null) {
+            throw new IllegalArgumentException("Callback cannot be null");
+        }
+        for (int i = mCallbacks.size() - 1; i >= 0; i--) {
+            MessageHandler handler = mCallbacks.get(i);
+            if (cb == handler.mCallback) {
+                return handler;
+            }
+        }
+        return null;
+    }
+
+    private final void postMessage(int what, Object obj, Bundle data) {
+        synchronized (mLock) {
+            for (int i = mCallbacks.size() - 1; i >= 0; i--) {
+                mCallbacks.get(i).post(what, obj, data);
+            }
+        }
+    }
+
+    /**
+     * Callback for receiving updates from the session. A Callback can be
+     * registered using {@link #registerCallback}.
+     */
+    public static abstract class Callback {
+        /**
+         * Override to handle the session being destroyed. The session is no
+         * longer valid after this call and calls to it will be ignored.
+         */
+        public void onSessionDestroyed() {
+        }
+
+        /**
+         * Override to handle custom events sent by the session owner without a
+         * specified interface. Controllers should only handle these for
+         * sessions they own.
+         *
+         * @param event The event from the session.
+         * @param extras Optional parameters for the event, may be null.
+         */
+        public void onSessionEvent(@NonNull String event, @Nullable Bundle extras) {
+        }
+
+        /**
+         * Override to handle changes in playback state.
+         *
+         * @param state The new playback state of the session
+         */
+        public void onPlaybackStateChanged(@Nullable PlaybackState state) {
+        }
+
+        /**
+         * Override to handle changes to the current metadata.
+         *
+         * @param metadata The current metadata for the session or null if none.
+         * @see MediaMetadata
+         */
+        public void onMetadataChanged(@Nullable MediaMetadata metadata) {
+        }
+
+        /**
+         * Override to handle changes to items in the queue.
+         *
+         * @param queue A list of items in the current play queue. It should
+         *            include the currently playing item as well as previous and
+         *            upcoming items if applicable.
+         * @see MediaSession.QueueItem
+         */
+        public void onQueueChanged(@Nullable List<MediaSession.QueueItem> queue) {
+        }
+
+        /**
+         * Override to handle changes to the queue title.
+         *
+         * @param title The title that should be displayed along with the play queue such as
+         *              "Now Playing". May be null if there is no such title.
+         */
+        public void onQueueTitleChanged(@Nullable CharSequence title) {
+        }
+
+        /**
+         * Override to handle changes to the {@link MediaSession} extras.
+         *
+         * @param extras The extras that can include other information associated with the
+         *               {@link MediaSession}.
+         */
+        public void onExtrasChanged(@Nullable Bundle extras) {
+        }
+
+        /**
+         * Override to handle changes to the audio info.
+         *
+         * @param info The current audio info for this session.
+         */
+        public void onAudioInfoChanged(PlaybackInfo info) {
+        }
+    }
+
+    /**
+     * Interface for controlling media playback on a session. This allows an app
+     * to send media transport commands to the session.
+     */
+    public final class TransportControls {
+        private static final String TAG = "TransportController";
+
+        private TransportControls() {
+        }
+
+        /**
+         * Request that the player prepare its playback. In other words, other sessions can continue
+         * to play during the preparation of this session. This method can be used to speed up the
+         * start of the playback. Once the preparation is done, the session will change its playback
+         * state to {@link PlaybackState#STATE_PAUSED}. Afterwards, {@link #play} can be called to
+         * start playback.
+         */
+        public void prepare() {
+            try {
+                mSessionBinder.prepare(mContext.getOpPackageName(), mCbStub);
+            } catch (RemoteException e) {
+                Log.wtf(TAG, "Error calling prepare.", e);
+            }
+        }
+
+        /**
+         * Request that the player prepare playback for a specific media id. In other words, other
+         * sessions can continue to play during the preparation of this session. This method can be
+         * used to speed up the start of the playback. Once the preparation is done, the session
+         * will change its playback state to {@link PlaybackState#STATE_PAUSED}. Afterwards,
+         * {@link #play} can be called to start playback. If the preparation is not needed,
+         * {@link #playFromMediaId} can be directly called without this method.
+         *
+         * @param mediaId The id of the requested media.
+         * @param extras Optional extras that can include extra information about the media item
+         *               to be prepared.
+         */
+        public void prepareFromMediaId(String mediaId, Bundle extras) {
+            if (TextUtils.isEmpty(mediaId)) {
+                throw new IllegalArgumentException(
+                        "You must specify a non-empty String for prepareFromMediaId.");
+            }
+            try {
+                mSessionBinder.prepareFromMediaId(mContext.getOpPackageName(), mCbStub, mediaId,
+                        extras);
+            } catch (RemoteException e) {
+                Log.wtf(TAG, "Error calling prepare(" + mediaId + ").", e);
+            }
+        }
+
+        /**
+         * Request that the player prepare playback for a specific search query. An empty or null
+         * query should be treated as a request to prepare any music. In other words, other sessions
+         * can continue to play during the preparation of this session. This method can be used to
+         * speed up the start of the playback. Once the preparation is done, the session will
+         * change its playback state to {@link PlaybackState#STATE_PAUSED}. Afterwards,
+         * {@link #play} can be called to start playback. If the preparation is not needed,
+         * {@link #playFromSearch} can be directly called without this method.
+         *
+         * @param query The search query.
+         * @param extras Optional extras that can include extra information
+         *               about the query.
+         */
+        public void prepareFromSearch(String query, Bundle extras) {
+            if (query == null) {
+                // This is to remain compatible with
+                // INTENT_ACTION_MEDIA_PLAY_FROM_SEARCH
+                query = "";
+            }
+            try {
+                mSessionBinder.prepareFromSearch(mContext.getOpPackageName(), mCbStub, query,
+                        extras);
+            } catch (RemoteException e) {
+                Log.wtf(TAG, "Error calling prepare(" + query + ").", e);
+            }
+        }
+
+        /**
+         * Request that the player prepare playback for a specific {@link Uri}. In other words,
+         * other sessions can continue to play during the preparation of this session. This method
+         * can be used to speed up the start of the playback. Once the preparation is done, the
+         * session will change its playback state to {@link PlaybackState#STATE_PAUSED}. Afterwards,
+         * {@link #play} can be called to start playback. If the preparation is not needed,
+         * {@link #playFromUri} can be directly called without this method.
+         *
+         * @param uri The URI of the requested media.
+         * @param extras Optional extras that can include extra information about the media item
+         *               to be prepared.
+         */
+        public void prepareFromUri(Uri uri, Bundle extras) {
+            if (uri == null || Uri.EMPTY.equals(uri)) {
+                throw new IllegalArgumentException(
+                        "You must specify a non-empty Uri for prepareFromUri.");
+            }
+            try {
+                mSessionBinder.prepareFromUri(mContext.getOpPackageName(), mCbStub, uri, extras);
+            } catch (RemoteException e) {
+                Log.wtf(TAG, "Error calling prepare(" + uri + ").", e);
+            }
+        }
+
+        /**
+         * Request that the player start its playback at its current position.
+         */
+        public void play() {
+            try {
+                mSessionBinder.play(mContext.getOpPackageName(), mCbStub);
+            } catch (RemoteException e) {
+                Log.wtf(TAG, "Error calling play.", e);
+            }
+        }
+
+        /**
+         * Request that the player start playback for a specific media id.
+         *
+         * @param mediaId The id of the requested media.
+         * @param extras Optional extras that can include extra information about the media item
+         *               to be played.
+         */
+        public void playFromMediaId(String mediaId, Bundle extras) {
+            if (TextUtils.isEmpty(mediaId)) {
+                throw new IllegalArgumentException(
+                        "You must specify a non-empty String for playFromMediaId.");
+            }
+            try {
+                mSessionBinder.playFromMediaId(mContext.getOpPackageName(), mCbStub, mediaId,
+                        extras);
+            } catch (RemoteException e) {
+                Log.wtf(TAG, "Error calling play(" + mediaId + ").", e);
+            }
+        }
+
+        /**
+         * Request that the player start playback for a specific search query.
+         * An empty or null query should be treated as a request to play any
+         * music.
+         *
+         * @param query The search query.
+         * @param extras Optional extras that can include extra information
+         *               about the query.
+         */
+        public void playFromSearch(String query, Bundle extras) {
+            if (query == null) {
+                // This is to remain compatible with
+                // INTENT_ACTION_MEDIA_PLAY_FROM_SEARCH
+                query = "";
+            }
+            try {
+                mSessionBinder.playFromSearch(mContext.getOpPackageName(), mCbStub, query, extras);
+            } catch (RemoteException e) {
+                Log.wtf(TAG, "Error calling play(" + query + ").", e);
+            }
+        }
+
+        /**
+         * Request that the player start playback for a specific {@link Uri}.
+         *
+         * @param uri The URI of the requested media.
+         * @param extras Optional extras that can include extra information about the media item
+         *               to be played.
+         */
+        public void playFromUri(Uri uri, Bundle extras) {
+            if (uri == null || Uri.EMPTY.equals(uri)) {
+                throw new IllegalArgumentException(
+                        "You must specify a non-empty Uri for playFromUri.");
+            }
+            try {
+                mSessionBinder.playFromUri(mContext.getOpPackageName(), mCbStub, uri, extras);
+            } catch (RemoteException e) {
+                Log.wtf(TAG, "Error calling play(" + uri + ").", e);
+            }
+        }
+
+        /**
+         * Play an item with a specific id in the play queue. If you specify an
+         * id that is not in the play queue, the behavior is undefined.
+         */
+        public void skipToQueueItem(long id) {
+            try {
+                mSessionBinder.skipToQueueItem(mContext.getOpPackageName(), mCbStub, id);
+            } catch (RemoteException e) {
+                Log.wtf(TAG, "Error calling skipToItem(" + id + ").", e);
+            }
+        }
+
+        /**
+         * Request that the player pause its playback and stay at its current
+         * position.
+         */
+        public void pause() {
+            try {
+                mSessionBinder.pause(mContext.getOpPackageName(), mCbStub);
+            } catch (RemoteException e) {
+                Log.wtf(TAG, "Error calling pause.", e);
+            }
+        }
+
+        /**
+         * Request that the player stop its playback; it may clear its state in
+         * whatever way is appropriate.
+         */
+        public void stop() {
+            try {
+                mSessionBinder.stop(mContext.getOpPackageName(), mCbStub);
+            } catch (RemoteException e) {
+                Log.wtf(TAG, "Error calling stop.", e);
+            }
+        }
+
+        /**
+         * Move to a new location in the media stream.
+         *
+         * @param pos Position to move to, in milliseconds.
+         */
+        public void seekTo(long pos) {
+            try {
+                mSessionBinder.seekTo(mContext.getOpPackageName(), mCbStub, pos);
+            } catch (RemoteException e) {
+                Log.wtf(TAG, "Error calling seekTo.", e);
+            }
+        }
+
+        /**
+         * Start fast forwarding. If playback is already fast forwarding this
+         * may increase the rate.
+         */
+        public void fastForward() {
+            try {
+                mSessionBinder.fastForward(mContext.getOpPackageName(), mCbStub);
+            } catch (RemoteException e) {
+                Log.wtf(TAG, "Error calling fastForward.", e);
+            }
+        }
+
+        /**
+         * Skip to the next item.
+         */
+        public void skipToNext() {
+            try {
+                mSessionBinder.next(mContext.getOpPackageName(), mCbStub);
+            } catch (RemoteException e) {
+                Log.wtf(TAG, "Error calling next.", e);
+            }
+        }
+
+        /**
+         * Start rewinding. If playback is already rewinding this may increase
+         * the rate.
+         */
+        public void rewind() {
+            try {
+                mSessionBinder.rewind(mContext.getOpPackageName(), mCbStub);
+            } catch (RemoteException e) {
+                Log.wtf(TAG, "Error calling rewind.", e);
+            }
+        }
+
+        /**
+         * Skip to the previous item.
+         */
+        public void skipToPrevious() {
+            try {
+                mSessionBinder.previous(mContext.getOpPackageName(), mCbStub);
+            } catch (RemoteException e) {
+                Log.wtf(TAG, "Error calling previous.", e);
+            }
+        }
+
+        /**
+         * Rate the current content. This will cause the rating to be set for
+         * the current user. The Rating type must match the type returned by
+         * {@link #getRatingType()}.
+         *
+         * @param rating The rating to set for the current content
+         */
+        public void setRating(Rating rating) {
+            try {
+                mSessionBinder.rate(mContext.getOpPackageName(), mCbStub, rating);
+            } catch (RemoteException e) {
+                Log.wtf(TAG, "Error calling rate.", e);
+            }
+        }
+
+        /**
+         * Send a custom action back for the {@link MediaSession} to perform.
+         *
+         * @param customAction The action to perform.
+         * @param args Optional arguments to supply to the {@link MediaSession} for this
+         *             custom action.
+         */
+        public void sendCustomAction(@NonNull PlaybackState.CustomAction customAction,
+                @Nullable Bundle args) {
+            if (customAction == null) {
+                throw new IllegalArgumentException("CustomAction cannot be null.");
+            }
+            sendCustomAction(customAction.getAction(), args);
+        }
+
+        /**
+         * Send the id and args from a custom action back for the {@link MediaSession} to perform.
+         *
+         * @see #sendCustomAction(PlaybackState.CustomAction action, Bundle args)
+         * @param action The action identifier of the {@link PlaybackState.CustomAction} as
+         *               specified by the {@link MediaSession}.
+         * @param args Optional arguments to supply to the {@link MediaSession} for this
+         *             custom action.
+         */
+        public void sendCustomAction(@NonNull String action, @Nullable Bundle args) {
+            if (TextUtils.isEmpty(action)) {
+                throw new IllegalArgumentException("CustomAction cannot be null.");
+            }
+            try {
+                mSessionBinder.sendCustomAction(mContext.getOpPackageName(), mCbStub, action, args);
+            } catch (RemoteException e) {
+                Log.d(TAG, "Dead object in sendCustomAction.", e);
+            }
+        }
+    }
+
+    /**
+     * Holds information about the current playback and how audio is handled for
+     * this session.
+     */
+    public static final class PlaybackInfo {
+        /**
+         * The session uses remote playback.
+         */
+        public static final int PLAYBACK_TYPE_REMOTE = 2;
+        /**
+         * The session uses local playback.
+         */
+        public static final int PLAYBACK_TYPE_LOCAL = 1;
+
+        private final int mVolumeType;
+        private final int mVolumeControl;
+        private final int mMaxVolume;
+        private final int mCurrentVolume;
+        private final AudioAttributes mAudioAttrs;
+
+        /**
+         * @hide
+         */
+        public PlaybackInfo(int type, AudioAttributes attrs, int control, int max, int current) {
+            mVolumeType = type;
+            mAudioAttrs = attrs;
+            mVolumeControl = control;
+            mMaxVolume = max;
+            mCurrentVolume = current;
+        }
+
+        /**
+         * Get the type of playback which affects volume handling. One of:
+         * <ul>
+         * <li>{@link #PLAYBACK_TYPE_LOCAL}</li>
+         * <li>{@link #PLAYBACK_TYPE_REMOTE}</li>
+         * </ul>
+         *
+         * @return The type of playback this session is using.
+         */
+        public int getPlaybackType() {
+            return mVolumeType;
+        }
+
+        /**
+         * Get the audio attributes for this session. The attributes will affect
+         * volume handling for the session. When the volume type is
+         * {@link PlaybackInfo#PLAYBACK_TYPE_REMOTE} these may be ignored by the
+         * remote volume handler.
+         *
+         * @return The attributes for this session.
+         */
+        public AudioAttributes getAudioAttributes() {
+            return mAudioAttrs;
+        }
+
+        /**
+         * Get the type of volume control that can be used. One of:
+         * <ul>
+         * <li>{@link VolumeProvider#VOLUME_CONTROL_ABSOLUTE}</li>
+         * <li>{@link VolumeProvider#VOLUME_CONTROL_RELATIVE}</li>
+         * <li>{@link VolumeProvider#VOLUME_CONTROL_FIXED}</li>
+         * </ul>
+         *
+         * @return The type of volume control that may be used with this
+         *         session.
+         */
+        public int getVolumeControl() {
+            return mVolumeControl;
+        }
+
+        /**
+         * Get the maximum volume that may be set for this session.
+         *
+         * @return The maximum allowed volume where this session is playing.
+         */
+        public int getMaxVolume() {
+            return mMaxVolume;
+        }
+
+        /**
+         * Get the current volume for this session.
+         *
+         * @return The current volume where this session is playing.
+         */
+        public int getCurrentVolume() {
+            return mCurrentVolume;
+        }
+    }
+
+    private final static class CallbackStub extends ISessionControllerCallback.Stub {
+        private final WeakReference<MediaController> mController;
+
+        public CallbackStub(MediaController controller) {
+            mController = new WeakReference<MediaController>(controller);
+        }
+
+        @Override
+        public void onSessionDestroyed() {
+            MediaController controller = mController.get();
+            if (controller != null) {
+                controller.postMessage(MSG_DESTROYED, null, null);
+            }
+        }
+
+        @Override
+        public void onEvent(String event, Bundle extras) {
+            MediaController controller = mController.get();
+            if (controller != null) {
+                controller.postMessage(MSG_EVENT, event, extras);
+            }
+        }
+
+        @Override
+        public void onPlaybackStateChanged(PlaybackState state) {
+            MediaController controller = mController.get();
+            if (controller != null) {
+                controller.postMessage(MSG_UPDATE_PLAYBACK_STATE, state, null);
+            }
+        }
+
+        @Override
+        public void onMetadataChanged(MediaMetadata metadata) {
+            MediaController controller = mController.get();
+            if (controller != null) {
+                controller.postMessage(MSG_UPDATE_METADATA, metadata, null);
+            }
+        }
+
+        @Override
+        public void onQueueChanged(ParceledListSlice parceledQueue) {
+            List<MediaSession.QueueItem> queue = parceledQueue == null ? null : parceledQueue
+                    .getList();
+            MediaController controller = mController.get();
+            if (controller != null) {
+                controller.postMessage(MSG_UPDATE_QUEUE, queue, null);
+            }
+        }
+
+        @Override
+        public void onQueueTitleChanged(CharSequence title) {
+            MediaController controller = mController.get();
+            if (controller != null) {
+                controller.postMessage(MSG_UPDATE_QUEUE_TITLE, title, null);
+            }
+        }
+
+        @Override
+        public void onExtrasChanged(Bundle extras) {
+            MediaController controller = mController.get();
+            if (controller != null) {
+                controller.postMessage(MSG_UPDATE_EXTRAS, extras, null);
+            }
+        }
+
+        @Override
+        public void onVolumeInfoChanged(ParcelableVolumeInfo pvi) {
+            MediaController controller = mController.get();
+            if (controller != null) {
+                PlaybackInfo info = new PlaybackInfo(pvi.volumeType, pvi.audioAttrs,
+                        pvi.controlType, pvi.maxVolume, pvi.currentVolume);
+                controller.postMessage(MSG_UPDATE_VOLUME, info, null);
+            }
+        }
+
+    }
+
+    private final static class MessageHandler extends Handler {
+        private final MediaController.Callback mCallback;
+        private boolean mRegistered = false;
+
+        public MessageHandler(Looper looper, MediaController.Callback cb) {
+            super(looper, null, true);
+            mCallback = cb;
+        }
+
+        @Override
+        public void handleMessage(Message msg) {
+            if (!mRegistered) {
+                return;
+            }
+            switch (msg.what) {
+                case MSG_EVENT:
+                    mCallback.onSessionEvent((String) msg.obj, msg.getData());
+                    break;
+                case MSG_UPDATE_PLAYBACK_STATE:
+                    mCallback.onPlaybackStateChanged((PlaybackState) msg.obj);
+                    break;
+                case MSG_UPDATE_METADATA:
+                    mCallback.onMetadataChanged((MediaMetadata) msg.obj);
+                    break;
+                case MSG_UPDATE_QUEUE:
+                    mCallback.onQueueChanged((List<MediaSession.QueueItem>) msg.obj);
+                    break;
+                case MSG_UPDATE_QUEUE_TITLE:
+                    mCallback.onQueueTitleChanged((CharSequence) msg.obj);
+                    break;
+                case MSG_UPDATE_EXTRAS:
+                    mCallback.onExtrasChanged((Bundle) msg.obj);
+                    break;
+                case MSG_UPDATE_VOLUME:
+                    mCallback.onAudioInfoChanged((PlaybackInfo) msg.obj);
+                    break;
+                case MSG_DESTROYED:
+                    mCallback.onSessionDestroyed();
+                    break;
+            }
+        }
+
+        public void post(int what, Object obj, Bundle data) {
+            Message msg = obtainMessage(what, obj);
+            msg.setData(data);
+            msg.sendToTarget();
+        }
+    }
+
+}
diff --git a/packages/MediaComponents/apex/java/android/media/session/MediaSession.aidl b/packages/MediaComponents/apex/java/android/media/session/MediaSession.aidl
new file mode 100644
index 0000000..f657cef
--- /dev/null
+++ b/packages/MediaComponents/apex/java/android/media/session/MediaSession.aidl
@@ -0,0 +1,19 @@
+/* Copyright 2014, The Android Open Source Project
+**
+** Licensed under the Apache License, Version 2.0 (the "License");
+** you may not use this file except in compliance with the License.
+** You may obtain a copy of the License at
+**
+**     http://www.apache.org/licenses/LICENSE-2.0
+**
+** Unless required by applicable law or agreed to in writing, software
+** distributed under the License is distributed on an "AS IS" BASIS,
+** WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+** See the License for the specific language governing permissions and
+** limitations under the License.
+*/
+
+package android.media.session;
+
+parcelable MediaSession.Token;
+parcelable MediaSession.QueueItem;
\ No newline at end of file
diff --git a/packages/MediaComponents/apex/java/android/media/session/MediaSession.java b/packages/MediaComponents/apex/java/android/media/session/MediaSession.java
new file mode 100644
index 0000000..d43cd30
--- /dev/null
+++ b/packages/MediaComponents/apex/java/android/media/session/MediaSession.java
@@ -0,0 +1,1554 @@
+/*
+ * Copyright (C) 2014 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package android.media.session;
+
+import android.annotation.IntDef;
+import android.annotation.NonNull;
+import android.annotation.Nullable;
+import android.annotation.UnsupportedAppUsage;
+import android.app.Activity;
+import android.app.PendingIntent;
+import android.content.Context;
+import android.content.Intent;
+import android.content.pm.ParceledListSlice;
+import android.media.AudioAttributes;
+import android.media.MediaDescription;
+import android.media.MediaMetadata;
+import android.media.Rating;
+import android.media.VolumeProvider;
+import android.net.Uri;
+import android.os.Bundle;
+import android.os.Handler;
+import android.os.Looper;
+import android.os.Message;
+import android.os.Parcel;
+import android.os.Parcelable;
+import android.os.RemoteException;
+import android.os.ResultReceiver;
+import android.os.UserHandle;
+import android.media.session.MediaSessionManager.RemoteUserInfo;
+import android.service.media.MediaBrowserService;
+import android.text.TextUtils;
+import android.util.Log;
+import android.util.Pair;
+import android.view.KeyEvent;
+import android.view.ViewConfiguration;
+
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.ref.WeakReference;
+import java.util.List;
+import java.util.Objects;
+
+/**
+ * Allows interaction with media controllers, volume keys, media buttons, and
+ * transport controls.
+ * <p>
+ * A MediaSession should be created when an app wants to publish media playback
+ * information or handle media keys. In general an app only needs one session
+ * for all playback, though multiple sessions can be created to provide finer
+ * grain controls of media.
+ * <p>
+ * Once a session is created the owner of the session may pass its
+ * {@link #getSessionToken() session token} to other processes to allow them to
+ * create a {@link MediaController} to interact with the session.
+ * <p>
+ * To receive commands, media keys, and other events a {@link Callback} must be
+ * set with {@link #setCallback(Callback)} and {@link #setActive(boolean)
+ * setActive(true)} must be called.
+ * <p>
+ * When an app is finished performing playback it must call {@link #release()}
+ * to clean up the session and notify any controllers.
+ * <p>
+ * MediaSession objects are thread safe.
+ */
+public final class MediaSession {
+    private static final String TAG = "MediaSession";
+
+    /**
+     * Set this flag on the session to indicate that it can handle media button
+     * events.
+     * @deprecated This flag is no longer used. All media sessions are expected to handle media
+     * button events now.
+     */
+    @Deprecated
+    public static final int FLAG_HANDLES_MEDIA_BUTTONS = 1 << 0;
+
+    /**
+     * Set this flag on the session to indicate that it handles transport
+     * control commands through its {@link Callback}.
+     * @deprecated This flag is no longer used. All media sessions are expected to handle transport
+     * controls now.
+     */
+    @Deprecated
+    public static final int FLAG_HANDLES_TRANSPORT_CONTROLS = 1 << 1;
+
+    /**
+     * System only flag for a session that needs to have priority over all other
+     * sessions. This flag ensures this session will receive media button events
+     * regardless of the current ordering in the system.
+     *
+     * @hide
+     */
+    public static final int FLAG_EXCLUSIVE_GLOBAL_PRIORITY = 1 << 16;
+
+    /**
+     * @hide
+     */
+    public static final int INVALID_UID = -1;
+
+    /**
+     * @hide
+     */
+    public static final int INVALID_PID = -1;
+
+    /** @hide */
+    @Retention(RetentionPolicy.SOURCE)
+    @IntDef(flag = true, value = {
+            FLAG_HANDLES_MEDIA_BUTTONS,
+            FLAG_HANDLES_TRANSPORT_CONTROLS,
+            FLAG_EXCLUSIVE_GLOBAL_PRIORITY })
+    public @interface SessionFlags { }
+
+    private final Object mLock = new Object();
+    private final int mMaxBitmapSize;
+
+    private final MediaSession.Token mSessionToken;
+    private final MediaController mController;
+    private final ISession mBinder;
+    private final CallbackStub mCbStub;
+
+    // Do not change the name of mCallback. Support lib accesses this by using reflection.
+    @UnsupportedAppUsage
+    private CallbackMessageHandler mCallback;
+    private VolumeProvider mVolumeProvider;
+    private PlaybackState mPlaybackState;
+
+    private boolean mActive = false;
+
+    /**
+     * Creates a new session. The session will automatically be registered with
+     * the system but will not be published until {@link #setActive(boolean)
+     * setActive(true)} is called. You must call {@link #release()} when
+     * finished with the session.
+     *
+     * @param context The context to use to create the session.
+     * @param tag A short name for debugging purposes.
+     */
+    public MediaSession(@NonNull Context context, @NonNull String tag) {
+        this(context, tag, UserHandle.myUserId());
+    }
+
+    /**
+     * Creates a new session as the specified user. To create a session as a
+     * user other than your own you must hold the
+     * {@link android.Manifest.permission#INTERACT_ACROSS_USERS_FULL}
+     * permission.
+     *
+     * @param context The context to use to create the session.
+     * @param tag A short name for debugging purposes.
+     * @param userId The user id to create the session as.
+     * @hide
+     */
+    public MediaSession(@NonNull Context context, @NonNull String tag, int userId) {
+        if (context == null) {
+            throw new IllegalArgumentException("context cannot be null.");
+        }
+        if (TextUtils.isEmpty(tag)) {
+            throw new IllegalArgumentException("tag cannot be null or empty");
+        }
+        mMaxBitmapSize = context.getResources().getDimensionPixelSize(
+                com.android.internal.R.dimen.config_mediaMetadataBitmapMaxSize);
+        mCbStub = new CallbackStub(this);
+        MediaSessionManager manager = (MediaSessionManager) context
+                .getSystemService(Context.MEDIA_SESSION_SERVICE);
+        try {
+            mBinder = manager.createSession(mCbStub, tag, userId);
+            mSessionToken = new Token(mBinder.getController());
+            mController = new MediaController(context, mSessionToken);
+        } catch (RemoteException e) {
+            throw new RuntimeException("Remote error creating session.", e);
+        }
+    }
+
+    /**
+     * Set the callback to receive updates for the MediaSession. This includes
+     * media button events and transport controls. The caller's thread will be
+     * used to post updates.
+     * <p>
+     * Set the callback to null to stop receiving updates.
+     *
+     * @param callback The callback object
+     */
+    public void setCallback(@Nullable Callback callback) {
+        setCallback(callback, null);
+    }
+
+    /**
+     * Set the callback to receive updates for the MediaSession. This includes
+     * media button events and transport controls.
+     * <p>
+     * Set the callback to null to stop receiving updates.
+     *
+     * @param callback The callback to receive updates on.
+     * @param handler The handler that events should be posted on.
+     */
+    public void setCallback(@Nullable Callback callback, @Nullable Handler handler) {
+        synchronized (mLock) {
+            if (mCallback != null) {
+                // We're updating the callback, clear the session from the old one.
+                mCallback.mCallback.mSession = null;
+                mCallback.removeCallbacksAndMessages(null);
+            }
+            if (callback == null) {
+                mCallback = null;
+                return;
+            }
+            if (handler == null) {
+                handler = new Handler();
+            }
+            callback.mSession = this;
+            CallbackMessageHandler msgHandler = new CallbackMessageHandler(handler.getLooper(),
+                    callback);
+            mCallback = msgHandler;
+        }
+    }
+
+    /**
+     * Set an intent for launching UI for this Session. This can be used as a
+     * quick link to an ongoing media screen. The intent should be for an
+     * activity that may be started using {@link Activity#startActivity(Intent)}.
+     *
+     * @param pi The intent to launch to show UI for this Session.
+     */
+    public void setSessionActivity(@Nullable PendingIntent pi) {
+        try {
+            mBinder.setLaunchPendingIntent(pi);
+        } catch (RemoteException e) {
+            Log.wtf(TAG, "Failure in setLaunchPendingIntent.", e);
+        }
+    }
+
+    /**
+     * Set a pending intent for your media button receiver to allow restarting
+     * playback after the session has been stopped. If your app is started in
+     * this way an {@link Intent#ACTION_MEDIA_BUTTON} intent will be sent via
+     * the pending intent.
+     *
+     * @param mbr The {@link PendingIntent} to send the media button event to.
+     */
+    public void setMediaButtonReceiver(@Nullable PendingIntent mbr) {
+        try {
+            mBinder.setMediaButtonReceiver(mbr);
+        } catch (RemoteException e) {
+            Log.wtf(TAG, "Failure in setMediaButtonReceiver.", e);
+        }
+    }
+
+    /**
+     * Set any flags for the session.
+     *
+     * @param flags The flags to set for this session.
+     */
+    public void setFlags(@SessionFlags int flags) {
+        try {
+            mBinder.setFlags(flags);
+        } catch (RemoteException e) {
+            Log.wtf(TAG, "Failure in setFlags.", e);
+        }
+    }
+
+    /**
+     * Set the attributes for this session's audio. This will affect the
+     * system's volume handling for this session. If
+     * {@link #setPlaybackToRemote} was previously called it will stop receiving
+     * volume commands and the system will begin sending volume changes to the
+     * appropriate stream.
+     * <p>
+     * By default sessions use attributes for media.
+     *
+     * @param attributes The {@link AudioAttributes} for this session's audio.
+     */
+    public void setPlaybackToLocal(AudioAttributes attributes) {
+        if (attributes == null) {
+            throw new IllegalArgumentException("Attributes cannot be null for local playback.");
+        }
+        try {
+            mBinder.setPlaybackToLocal(attributes);
+        } catch (RemoteException e) {
+            Log.wtf(TAG, "Failure in setPlaybackToLocal.", e);
+        }
+    }
+
+    /**
+     * Configure this session to use remote volume handling. This must be called
+     * to receive volume button events, otherwise the system will adjust the
+     * appropriate stream volume for this session. If
+     * {@link #setPlaybackToLocal} was previously called the system will stop
+     * handling volume changes for this session and pass them to the volume
+     * provider instead.
+     *
+     * @param volumeProvider The provider that will handle volume changes. May
+     *            not be null.
+     */
+    public void setPlaybackToRemote(@NonNull VolumeProvider volumeProvider) {
+        if (volumeProvider == null) {
+            throw new IllegalArgumentException("volumeProvider may not be null!");
+        }
+        synchronized (mLock) {
+            mVolumeProvider = volumeProvider;
+        }
+        volumeProvider.setCallback(new VolumeProvider.Callback() {
+            @Override
+            public void onVolumeChanged(VolumeProvider volumeProvider) {
+                notifyRemoteVolumeChanged(volumeProvider);
+            }
+        });
+
+        try {
+            mBinder.setPlaybackToRemote(volumeProvider.getVolumeControl(),
+                    volumeProvider.getMaxVolume());
+            mBinder.setCurrentVolume(volumeProvider.getCurrentVolume());
+        } catch (RemoteException e) {
+            Log.wtf(TAG, "Failure in setPlaybackToRemote.", e);
+        }
+    }
+
+    /**
+     * Set if this session is currently active and ready to receive commands. If
+     * set to false your session's controller may not be discoverable. You must
+     * set the session to active before it can start receiving media button
+     * events or transport commands.
+     *
+     * @param active Whether this session is active or not.
+     */
+    public void setActive(boolean active) {
+        if (mActive == active) {
+            return;
+        }
+        try {
+            mBinder.setActive(active);
+            mActive = active;
+        } catch (RemoteException e) {
+            Log.wtf(TAG, "Failure in setActive.", e);
+        }
+    }
+
+    /**
+     * Get the current active state of this session.
+     *
+     * @return True if the session is active, false otherwise.
+     */
+    public boolean isActive() {
+        return mActive;
+    }
+
+    /**
+     * Send a proprietary event to all MediaControllers listening to this
+     * Session. It's up to the Controller/Session owner to determine the meaning
+     * of any events.
+     *
+     * @param event The name of the event to send
+     * @param extras Any extras included with the event
+     */
+    public void sendSessionEvent(@NonNull String event, @Nullable Bundle extras) {
+        if (TextUtils.isEmpty(event)) {
+            throw new IllegalArgumentException("event cannot be null or empty");
+        }
+        try {
+            mBinder.sendEvent(event, extras);
+        } catch (RemoteException e) {
+            Log.wtf(TAG, "Error sending event", e);
+        }
+    }
+
+    /**
+     * This must be called when an app has finished performing playback. If
+     * playback is expected to start again shortly the session can be left open,
+     * but it must be released if your activity or service is being destroyed.
+     */
+    public void release() {
+        try {
+            mBinder.destroy();
+        } catch (RemoteException e) {
+            Log.wtf(TAG, "Error releasing session: ", e);
+        }
+    }
+
+    /**
+     * Retrieve a token object that can be used by apps to create a
+     * {@link MediaController} for interacting with this session. The owner of
+     * the session is responsible for deciding how to distribute these tokens.
+     *
+     * @return A token that can be used to create a MediaController for this
+     *         session
+     */
+    public @NonNull Token getSessionToken() {
+        return mSessionToken;
+    }
+
+    /**
+     * Get a controller for this session. This is a convenience method to avoid
+     * having to cache your own controller in process.
+     *
+     * @return A controller for this session.
+     */
+    public @NonNull MediaController getController() {
+        return mController;
+    }
+
+    /**
+     * Update the current playback state.
+     *
+     * @param state The current state of playback
+     */
+    public void setPlaybackState(@Nullable PlaybackState state) {
+        mPlaybackState = state;
+        try {
+            mBinder.setPlaybackState(state);
+        } catch (RemoteException e) {
+            Log.wtf(TAG, "Dead object in setPlaybackState.", e);
+        }
+    }
+
+    /**
+     * Update the current metadata. New metadata can be created using
+     * {@link android.media.MediaMetadata.Builder}. This operation may take time proportional to
+     * the size of the bitmap to replace large bitmaps with a scaled down copy.
+     *
+     * @param metadata The new metadata
+     * @see android.media.MediaMetadata.Builder#putBitmap
+     */
+    public void setMetadata(@Nullable MediaMetadata metadata) {
+        if (metadata != null) {
+            metadata = (new MediaMetadata.Builder(metadata, mMaxBitmapSize)).build();
+        }
+        try {
+            mBinder.setMetadata(metadata);
+        } catch (RemoteException e) {
+            Log.wtf(TAG, "Dead object in setPlaybackState.", e);
+        }
+    }
+
+    /**
+     * Update the list of items in the play queue. It is an ordered list and
+     * should contain the current item, and previous or upcoming items if they
+     * exist. Specify null if there is no current play queue.
+     * <p>
+     * The queue should be of reasonable size. If the play queue is unbounded
+     * within your app, it is better to send a reasonable amount in a sliding
+     * window instead.
+     *
+     * @param queue A list of items in the play queue.
+     */
+    public void setQueue(@Nullable List<QueueItem> queue) {
+        try {
+            mBinder.setQueue(queue == null ? null : new ParceledListSlice<QueueItem>(queue));
+        } catch (RemoteException e) {
+            Log.wtf("Dead object in setQueue.", e);
+        }
+    }
+
+    /**
+     * Set the title of the play queue. The UI should display this title along
+     * with the play queue itself.
+     * e.g. "Play Queue", "Now Playing", or an album name.
+     *
+     * @param title The title of the play queue.
+     */
+    public void setQueueTitle(@Nullable CharSequence title) {
+        try {
+            mBinder.setQueueTitle(title);
+        } catch (RemoteException e) {
+            Log.wtf("Dead object in setQueueTitle.", e);
+        }
+    }
+
+    /**
+     * Set the style of rating used by this session. Apps trying to set the
+     * rating should use this style. Must be one of the following:
+     * <ul>
+     * <li>{@link Rating#RATING_NONE}</li>
+     * <li>{@link Rating#RATING_3_STARS}</li>
+     * <li>{@link Rating#RATING_4_STARS}</li>
+     * <li>{@link Rating#RATING_5_STARS}</li>
+     * <li>{@link Rating#RATING_HEART}</li>
+     * <li>{@link Rating#RATING_PERCENTAGE}</li>
+     * <li>{@link Rating#RATING_THUMB_UP_DOWN}</li>
+     * </ul>
+     */
+    public void setRatingType(@Rating.Style int type) {
+        try {
+            mBinder.setRatingType(type);
+        } catch (RemoteException e) {
+            Log.e(TAG, "Error in setRatingType.", e);
+        }
+    }
+
+    /**
+     * Set some extras that can be associated with the {@link MediaSession}. No assumptions should
+     * be made as to how a {@link MediaController} will handle these extras.
+     * Keys should be fully qualified (e.g. com.example.MY_EXTRA) to avoid conflicts.
+     *
+     * @param extras The extras associated with the {@link MediaSession}.
+     */
+    public void setExtras(@Nullable Bundle extras) {
+        try {
+            mBinder.setExtras(extras);
+        } catch (RemoteException e) {
+            Log.wtf("Dead object in setExtras.", e);
+        }
+    }
+
+    /**
+     * Gets the controller information who sent the current request.
+     * <p>
+     * Note: This is only valid while in a request callback, such as {@link Callback#onPlay}.
+     *
+     * @throws IllegalStateException If this method is called outside of {@link Callback} methods.
+     * @see MediaSessionManager#isTrustedForMediaControl(RemoteUserInfo)
+     */
+    public final @NonNull RemoteUserInfo getCurrentControllerInfo() {
+        if (mCallback == null || mCallback.mCurrentControllerInfo == null) {
+            throw new IllegalStateException(
+                    "This should be called inside of MediaSession.Callback methods");
+        }
+        return mCallback.mCurrentControllerInfo;
+    }
+
+    /**
+     * Notify the system that the remote volume changed.
+     *
+     * @param provider The provider that is handling volume changes.
+     * @hide
+     */
+    public void notifyRemoteVolumeChanged(VolumeProvider provider) {
+        synchronized (mLock) {
+            if (provider == null || provider != mVolumeProvider) {
+                Log.w(TAG, "Received update from stale volume provider");
+                return;
+            }
+        }
+        try {
+            mBinder.setCurrentVolume(provider.getCurrentVolume());
+        } catch (RemoteException e) {
+            Log.e(TAG, "Error in notifyVolumeChanged", e);
+        }
+    }
+
+    /**
+     * Returns the name of the package that sent the last media button, transport control, or
+     * command from controllers and the system. This is only valid while in a request callback, such
+     * as {@link Callback#onPlay}.
+     *
+     * @hide
+     */
+    @UnsupportedAppUsage
+    public String getCallingPackage() {
+        if (mCallback != null && mCallback.mCurrentControllerInfo != null) {
+            return mCallback.mCurrentControllerInfo.getPackageName();
+        }
+        return null;
+    }
+
+    private void dispatchPrepare(RemoteUserInfo caller) {
+        postToCallback(caller, CallbackMessageHandler.MSG_PREPARE, null, null);
+    }
+
+    private void dispatchPrepareFromMediaId(RemoteUserInfo caller, String mediaId, Bundle extras) {
+        postToCallback(caller, CallbackMessageHandler.MSG_PREPARE_MEDIA_ID, mediaId, extras);
+    }
+
+    private void dispatchPrepareFromSearch(RemoteUserInfo caller, String query, Bundle extras) {
+        postToCallback(caller, CallbackMessageHandler.MSG_PREPARE_SEARCH, query, extras);
+    }
+
+    private void dispatchPrepareFromUri(RemoteUserInfo caller, Uri uri, Bundle extras) {
+        postToCallback(caller, CallbackMessageHandler.MSG_PREPARE_URI, uri, extras);
+    }
+
+    private void dispatchPlay(RemoteUserInfo caller) {
+        postToCallback(caller, CallbackMessageHandler.MSG_PLAY, null, null);
+    }
+
+    private void dispatchPlayFromMediaId(RemoteUserInfo caller, String mediaId, Bundle extras) {
+        postToCallback(caller, CallbackMessageHandler.MSG_PLAY_MEDIA_ID, mediaId, extras);
+    }
+
+    private void dispatchPlayFromSearch(RemoteUserInfo caller, String query, Bundle extras) {
+        postToCallback(caller, CallbackMessageHandler.MSG_PLAY_SEARCH, query, extras);
+    }
+
+    private void dispatchPlayFromUri(RemoteUserInfo caller, Uri uri, Bundle extras) {
+        postToCallback(caller, CallbackMessageHandler.MSG_PLAY_URI, uri, extras);
+    }
+
+    private void dispatchSkipToItem(RemoteUserInfo caller, long id) {
+        postToCallback(caller, CallbackMessageHandler.MSG_SKIP_TO_ITEM, id, null);
+    }
+
+    private void dispatchPause(RemoteUserInfo caller) {
+        postToCallback(caller, CallbackMessageHandler.MSG_PAUSE, null, null);
+    }
+
+    private void dispatchStop(RemoteUserInfo caller) {
+        postToCallback(caller, CallbackMessageHandler.MSG_STOP, null, null);
+    }
+
+    private void dispatchNext(RemoteUserInfo caller) {
+        postToCallback(caller, CallbackMessageHandler.MSG_NEXT, null, null);
+    }
+
+    private void dispatchPrevious(RemoteUserInfo caller) {
+        postToCallback(caller, CallbackMessageHandler.MSG_PREVIOUS, null, null);
+    }
+
+    private void dispatchFastForward(RemoteUserInfo caller) {
+        postToCallback(caller, CallbackMessageHandler.MSG_FAST_FORWARD, null, null);
+    }
+
+    private void dispatchRewind(RemoteUserInfo caller) {
+        postToCallback(caller, CallbackMessageHandler.MSG_REWIND, null, null);
+    }
+
+    private void dispatchSeekTo(RemoteUserInfo caller, long pos) {
+        postToCallback(caller, CallbackMessageHandler.MSG_SEEK_TO, pos, null);
+    }
+
+    private void dispatchRate(RemoteUserInfo caller, Rating rating) {
+        postToCallback(caller, CallbackMessageHandler.MSG_RATE, rating, null);
+    }
+
+    private void dispatchCustomAction(RemoteUserInfo caller, String action, Bundle args) {
+        postToCallback(caller, CallbackMessageHandler.MSG_CUSTOM_ACTION, action, args);
+    }
+
+    private void dispatchMediaButton(RemoteUserInfo caller, Intent mediaButtonIntent) {
+        postToCallback(caller, CallbackMessageHandler.MSG_MEDIA_BUTTON, mediaButtonIntent, null);
+    }
+
+    private void dispatchMediaButtonDelayed(RemoteUserInfo info, Intent mediaButtonIntent,
+            long delay) {
+        postToCallbackDelayed(info, CallbackMessageHandler.MSG_PLAY_PAUSE_KEY_DOUBLE_TAP_TIMEOUT,
+                mediaButtonIntent, null, delay);
+    }
+
+    private void dispatchAdjustVolume(RemoteUserInfo caller, int direction) {
+        postToCallback(caller, CallbackMessageHandler.MSG_ADJUST_VOLUME, direction, null);
+    }
+
+    private void dispatchSetVolumeTo(RemoteUserInfo caller, int volume) {
+        postToCallback(caller, CallbackMessageHandler.MSG_SET_VOLUME, volume, null);
+    }
+
+    private void dispatchCommand(RemoteUserInfo caller, String command, Bundle args,
+            ResultReceiver resultCb) {
+        Command cmd = new Command(command, args, resultCb);
+        postToCallback(caller, CallbackMessageHandler.MSG_COMMAND, cmd, null);
+    }
+
+    private void postToCallback(RemoteUserInfo caller, int what, Object obj, Bundle data) {
+        postToCallbackDelayed(caller, what, obj, data, 0);
+    }
+
+    private void postToCallbackDelayed(RemoteUserInfo caller, int what, Object obj, Bundle data,
+            long delay) {
+        synchronized (mLock) {
+            if (mCallback != null) {
+                mCallback.post(caller, what, obj, data, delay);
+            }
+        }
+    }
+
+    /**
+     * Return true if this is considered an active playback state.
+     *
+     * @hide
+     */
+    public static boolean isActiveState(int state) {
+        switch (state) {
+            case PlaybackState.STATE_FAST_FORWARDING:
+            case PlaybackState.STATE_REWINDING:
+            case PlaybackState.STATE_SKIPPING_TO_PREVIOUS:
+            case PlaybackState.STATE_SKIPPING_TO_NEXT:
+            case PlaybackState.STATE_BUFFERING:
+            case PlaybackState.STATE_CONNECTING:
+            case PlaybackState.STATE_PLAYING:
+                return true;
+        }
+        return false;
+    }
+
+    /**
+     * Represents an ongoing session. This may be passed to apps by the session
+     * owner to allow them to create a {@link MediaController} to communicate with
+     * the session.
+     */
+    public static final class Token implements Parcelable {
+
+        private ISessionController mBinder;
+
+        /**
+         * @hide
+         */
+        public Token(ISessionController binder) {
+            mBinder = binder;
+        }
+
+        @Override
+        public int describeContents() {
+            return 0;
+        }
+
+        @Override
+        public void writeToParcel(Parcel dest, int flags) {
+            dest.writeStrongBinder(mBinder.asBinder());
+        }
+
+        @Override
+        public int hashCode() {
+            final int prime = 31;
+            int result = 1;
+            result = prime * result + ((mBinder == null) ? 0 : mBinder.asBinder().hashCode());
+            return result;
+        }
+
+        @Override
+        public boolean equals(Object obj) {
+            if (this == obj)
+                return true;
+            if (obj == null)
+                return false;
+            if (getClass() != obj.getClass())
+                return false;
+            Token other = (Token) obj;
+            if (mBinder == null) {
+                if (other.mBinder != null)
+                    return false;
+            } else if (!mBinder.asBinder().equals(other.mBinder.asBinder()))
+                return false;
+            return true;
+        }
+
+        ISessionController getBinder() {
+            return mBinder;
+        }
+
+        public static final Parcelable.Creator<Token> CREATOR
+                = new Parcelable.Creator<Token>() {
+            @Override
+            public Token createFromParcel(Parcel in) {
+                return new Token(ISessionController.Stub.asInterface(in.readStrongBinder()));
+            }
+
+            @Override
+            public Token[] newArray(int size) {
+                return new Token[size];
+            }
+        };
+    }
+
+    /**
+     * Receives media buttons, transport controls, and commands from controllers
+     * and the system. A callback may be set using {@link #setCallback}.
+     */
+    public abstract static class Callback {
+
+        private MediaSession mSession;
+        private CallbackMessageHandler mHandler;
+        private boolean mMediaPlayPauseKeyPending;
+
+        public Callback() {
+        }
+
+        /**
+         * Called when a controller has sent a command to this session.
+         * The owner of the session may handle custom commands but is not
+         * required to.
+         *
+         * @param command The command name.
+         * @param args Optional parameters for the command, may be null.
+         * @param cb A result receiver to which a result may be sent by the command, may be null.
+         */
+        public void onCommand(@NonNull String command, @Nullable Bundle args,
+                @Nullable ResultReceiver cb) {
+        }
+
+        /**
+         * Called when a media button is pressed and this session has the
+         * highest priority or a controller sends a media button event to the
+         * session. The default behavior will call the relevant method if the
+         * action for it was set.
+         * <p>
+         * The intent will be of type {@link Intent#ACTION_MEDIA_BUTTON} with a
+         * KeyEvent in {@link Intent#EXTRA_KEY_EVENT}
+         *
+         * @param mediaButtonIntent an intent containing the KeyEvent as an
+         *            extra
+         * @return True if the event was handled, false otherwise.
+         */
+        public boolean onMediaButtonEvent(@NonNull Intent mediaButtonIntent) {
+            if (mSession != null && mHandler != null
+                    && Intent.ACTION_MEDIA_BUTTON.equals(mediaButtonIntent.getAction())) {
+                KeyEvent ke = mediaButtonIntent.getParcelableExtra(Intent.EXTRA_KEY_EVENT);
+                if (ke != null && ke.getAction() == KeyEvent.ACTION_DOWN) {
+                    PlaybackState state = mSession.mPlaybackState;
+                    long validActions = state == null ? 0 : state.getActions();
+                    switch (ke.getKeyCode()) {
+                        case KeyEvent.KEYCODE_MEDIA_PLAY_PAUSE:
+                        case KeyEvent.KEYCODE_HEADSETHOOK:
+                            if (ke.getRepeatCount() > 0) {
+                                // Consider long-press as a single tap.
+                                handleMediaPlayPauseKeySingleTapIfPending();
+                            } else if (mMediaPlayPauseKeyPending) {
+                                // Consider double tap as the next.
+                                mHandler.removeMessages(CallbackMessageHandler
+                                        .MSG_PLAY_PAUSE_KEY_DOUBLE_TAP_TIMEOUT);
+                                mMediaPlayPauseKeyPending = false;
+                                if ((validActions & PlaybackState.ACTION_SKIP_TO_NEXT) != 0) {
+                                    onSkipToNext();
+                                }
+                            } else {
+                                mMediaPlayPauseKeyPending = true;
+                                mSession.dispatchMediaButtonDelayed(
+                                        mSession.getCurrentControllerInfo(),
+                                        mediaButtonIntent, ViewConfiguration.getDoubleTapTimeout());
+                            }
+                            return true;
+                        default:
+                            // If another key is pressed within double tap timeout, consider the
+                            // pending play/pause as a single tap to handle media keys in order.
+                            handleMediaPlayPauseKeySingleTapIfPending();
+                            break;
+                    }
+
+                    switch (ke.getKeyCode()) {
+                        case KeyEvent.KEYCODE_MEDIA_PLAY:
+                            if ((validActions & PlaybackState.ACTION_PLAY) != 0) {
+                                onPlay();
+                                return true;
+                            }
+                            break;
+                        case KeyEvent.KEYCODE_MEDIA_PAUSE:
+                            if ((validActions & PlaybackState.ACTION_PAUSE) != 0) {
+                                onPause();
+                                return true;
+                            }
+                            break;
+                        case KeyEvent.KEYCODE_MEDIA_NEXT:
+                            if ((validActions & PlaybackState.ACTION_SKIP_TO_NEXT) != 0) {
+                                onSkipToNext();
+                                return true;
+                            }
+                            break;
+                        case KeyEvent.KEYCODE_MEDIA_PREVIOUS:
+                            if ((validActions & PlaybackState.ACTION_SKIP_TO_PREVIOUS) != 0) {
+                                onSkipToPrevious();
+                                return true;
+                            }
+                            break;
+                        case KeyEvent.KEYCODE_MEDIA_STOP:
+                            if ((validActions & PlaybackState.ACTION_STOP) != 0) {
+                                onStop();
+                                return true;
+                            }
+                            break;
+                        case KeyEvent.KEYCODE_MEDIA_FAST_FORWARD:
+                            if ((validActions & PlaybackState.ACTION_FAST_FORWARD) != 0) {
+                                onFastForward();
+                                return true;
+                            }
+                            break;
+                        case KeyEvent.KEYCODE_MEDIA_REWIND:
+                            if ((validActions & PlaybackState.ACTION_REWIND) != 0) {
+                                onRewind();
+                                return true;
+                            }
+                            break;
+                    }
+                }
+            }
+            return false;
+        }
+
+        private void handleMediaPlayPauseKeySingleTapIfPending() {
+            if (!mMediaPlayPauseKeyPending) {
+                return;
+            }
+            mMediaPlayPauseKeyPending = false;
+            mHandler.removeMessages(CallbackMessageHandler.MSG_PLAY_PAUSE_KEY_DOUBLE_TAP_TIMEOUT);
+            PlaybackState state = mSession.mPlaybackState;
+            long validActions = state == null ? 0 : state.getActions();
+            boolean isPlaying = state != null
+                    && state.getState() == PlaybackState.STATE_PLAYING;
+            boolean canPlay = (validActions & (PlaybackState.ACTION_PLAY_PAUSE
+                        | PlaybackState.ACTION_PLAY)) != 0;
+            boolean canPause = (validActions & (PlaybackState.ACTION_PLAY_PAUSE
+                        | PlaybackState.ACTION_PAUSE)) != 0;
+            if (isPlaying && canPause) {
+                onPause();
+            } else if (!isPlaying && canPlay) {
+                onPlay();
+            }
+        }
+
+        /**
+         * Override to handle requests to prepare playback. During the preparation, a session should
+         * not hold audio focus in order to allow other sessions play seamlessly. The state of
+         * playback should be updated to {@link PlaybackState#STATE_PAUSED} after the preparation is
+         * done.
+         */
+        public void onPrepare() {
+        }
+
+        /**
+         * Override to handle requests to prepare for playing a specific mediaId that was provided
+         * by your app's {@link MediaBrowserService}. During the preparation, a session should not
+         * hold audio focus in order to allow other sessions play seamlessly. The state of playback
+         * should be updated to {@link PlaybackState#STATE_PAUSED} after the preparation is done.
+         * The playback of the prepared content should start in the implementation of
+         * {@link #onPlay}. Override {@link #onPlayFromMediaId} to handle requests for starting
+         * playback without preparation.
+         */
+        public void onPrepareFromMediaId(String mediaId, Bundle extras) {
+        }
+
+        /**
+         * Override to handle requests to prepare playback from a search query. An empty query
+         * indicates that the app may prepare any music. The implementation should attempt to make a
+         * smart choice about what to play. During the preparation, a session should not hold audio
+         * focus in order to allow other sessions play seamlessly. The state of playback should be
+         * updated to {@link PlaybackState#STATE_PAUSED} after the preparation is done. The playback
+         * of the prepared content should start in the implementation of {@link #onPlay}. Override
+         * {@link #onPlayFromSearch} to handle requests for starting playback without preparation.
+         */
+        public void onPrepareFromSearch(String query, Bundle extras) {
+        }
+
+        /**
+         * Override to handle requests to prepare a specific media item represented by a URI.
+         * During the preparation, a session should not hold audio focus in order to allow
+         * other sessions play seamlessly. The state of playback should be updated to
+         * {@link PlaybackState#STATE_PAUSED} after the preparation is done.
+         * The playback of the prepared content should start in the implementation of
+         * {@link #onPlay}. Override {@link #onPlayFromUri} to handle requests
+         * for starting playback without preparation.
+         */
+        public void onPrepareFromUri(Uri uri, Bundle extras) {
+        }
+
+        /**
+         * Override to handle requests to begin playback.
+         */
+        public void onPlay() {
+        }
+
+        /**
+         * Override to handle requests to begin playback from a search query. An
+         * empty query indicates that the app may play any music. The
+         * implementation should attempt to make a smart choice about what to
+         * play.
+         */
+        public void onPlayFromSearch(String query, Bundle extras) {
+        }
+
+        /**
+         * Override to handle requests to play a specific mediaId that was
+         * provided by your app's {@link MediaBrowserService}.
+         */
+        public void onPlayFromMediaId(String mediaId, Bundle extras) {
+        }
+
+        /**
+         * Override to handle requests to play a specific media item represented by a URI.
+         */
+        public void onPlayFromUri(Uri uri, Bundle extras) {
+        }
+
+        /**
+         * Override to handle requests to play an item with a given id from the
+         * play queue.
+         */
+        public void onSkipToQueueItem(long id) {
+        }
+
+        /**
+         * Override to handle requests to pause playback.
+         */
+        public void onPause() {
+        }
+
+        /**
+         * Override to handle requests to skip to the next media item.
+         */
+        public void onSkipToNext() {
+        }
+
+        /**
+         * Override to handle requests to skip to the previous media item.
+         */
+        public void onSkipToPrevious() {
+        }
+
+        /**
+         * Override to handle requests to fast forward.
+         */
+        public void onFastForward() {
+        }
+
+        /**
+         * Override to handle requests to rewind.
+         */
+        public void onRewind() {
+        }
+
+        /**
+         * Override to handle requests to stop playback.
+         */
+        public void onStop() {
+        }
+
+        /**
+         * Override to handle requests to seek to a specific position in ms.
+         *
+         * @param pos New position to move to, in milliseconds.
+         */
+        public void onSeekTo(long pos) {
+        }
+
+        /**
+         * Override to handle the item being rated.
+         *
+         * @param rating
+         */
+        public void onSetRating(@NonNull Rating rating) {
+        }
+
+        /**
+         * Called when a {@link MediaController} wants a {@link PlaybackState.CustomAction} to be
+         * performed.
+         *
+         * @param action The action that was originally sent in the
+         *               {@link PlaybackState.CustomAction}.
+         * @param extras Optional extras specified by the {@link MediaController}.
+         */
+        public void onCustomAction(@NonNull String action, @Nullable Bundle extras) {
+        }
+    }
+
+    /**
+     * @hide
+     */
+    public static class CallbackStub extends ISessionCallback.Stub {
+        private WeakReference<MediaSession> mMediaSession;
+
+        public CallbackStub(MediaSession session) {
+            mMediaSession = new WeakReference<>(session);
+        }
+
+        private static RemoteUserInfo createRemoteUserInfo(String packageName, int pid, int uid,
+                ISessionControllerCallback caller) {
+            return new RemoteUserInfo(packageName, pid, uid,
+                    caller != null ? caller.asBinder() : null);
+        }
+
+        @Override
+        public void onCommand(String packageName, int pid, int uid,
+                ISessionControllerCallback caller, String command, Bundle args, ResultReceiver cb) {
+            MediaSession session = mMediaSession.get();
+            if (session != null) {
+                session.dispatchCommand(createRemoteUserInfo(packageName, pid, uid, caller),
+                        command, args, cb);
+            }
+        }
+
+        @Override
+        public void onMediaButton(String packageName, int pid, int uid, Intent mediaButtonIntent,
+                int sequenceNumber, ResultReceiver cb) {
+            MediaSession session = mMediaSession.get();
+            try {
+                if (session != null) {
+                    session.dispatchMediaButton(createRemoteUserInfo(packageName, pid, uid, null),
+                            mediaButtonIntent);
+                }
+            } finally {
+                if (cb != null) {
+                    cb.send(sequenceNumber, null);
+                }
+            }
+        }
+
+        @Override
+        public void onMediaButtonFromController(String packageName, int pid, int uid,
+                ISessionControllerCallback caller, Intent mediaButtonIntent) {
+            MediaSession session = mMediaSession.get();
+            if (session != null) {
+                session.dispatchMediaButton(createRemoteUserInfo(packageName, pid, uid, caller),
+                        mediaButtonIntent);
+            }
+        }
+
+        @Override
+        public void onPrepare(String packageName, int pid, int uid,
+                ISessionControllerCallback caller) {
+            MediaSession session = mMediaSession.get();
+            if (session != null) {
+                session.dispatchPrepare(createRemoteUserInfo(packageName, pid, uid, caller));
+            }
+        }
+
+        @Override
+        public void onPrepareFromMediaId(String packageName, int pid, int uid,
+                ISessionControllerCallback caller, String mediaId,
+                Bundle extras) {
+            MediaSession session = mMediaSession.get();
+            if (session != null) {
+                session.dispatchPrepareFromMediaId(
+                        createRemoteUserInfo(packageName, pid, uid, caller), mediaId, extras);
+            }
+        }
+
+        @Override
+        public void onPrepareFromSearch(String packageName, int pid, int uid,
+                ISessionControllerCallback caller, String query,
+                Bundle extras) {
+            MediaSession session = mMediaSession.get();
+            if (session != null) {
+                session.dispatchPrepareFromSearch(
+                        createRemoteUserInfo(packageName, pid, uid, caller), query, extras);
+            }
+        }
+
+        @Override
+        public void onPrepareFromUri(String packageName, int pid, int uid,
+                ISessionControllerCallback caller, Uri uri, Bundle extras) {
+            MediaSession session = mMediaSession.get();
+            if (session != null) {
+                session.dispatchPrepareFromUri(createRemoteUserInfo(packageName, pid, uid, caller),
+                        uri, extras);
+            }
+        }
+
+        @Override
+        public void onPlay(String packageName, int pid, int uid,
+                ISessionControllerCallback caller) {
+            MediaSession session = mMediaSession.get();
+            if (session != null) {
+                session.dispatchPlay(createRemoteUserInfo(packageName, pid, uid, caller));
+            }
+        }
+
+        @Override
+        public void onPlayFromMediaId(String packageName, int pid, int uid,
+                ISessionControllerCallback caller, String mediaId,
+                Bundle extras) {
+            MediaSession session = mMediaSession.get();
+            if (session != null) {
+                session.dispatchPlayFromMediaId(createRemoteUserInfo(packageName, pid, uid, caller),
+                        mediaId, extras);
+            }
+        }
+
+        @Override
+        public void onPlayFromSearch(String packageName, int pid, int uid,
+                ISessionControllerCallback caller, String query,
+                Bundle extras) {
+            MediaSession session = mMediaSession.get();
+            if (session != null) {
+                session.dispatchPlayFromSearch(createRemoteUserInfo(packageName, pid, uid, caller),
+                        query, extras);
+            }
+        }
+
+        @Override
+        public void onPlayFromUri(String packageName, int pid, int uid,
+                ISessionControllerCallback caller, Uri uri, Bundle extras) {
+            MediaSession session = mMediaSession.get();
+            if (session != null) {
+                session.dispatchPlayFromUri(createRemoteUserInfo(packageName, pid, uid, caller),
+                        uri, extras);
+            }
+        }
+
+        @Override
+        public void onSkipToTrack(String packageName, int pid, int uid,
+                ISessionControllerCallback caller, long id) {
+            MediaSession session = mMediaSession.get();
+            if (session != null) {
+                session.dispatchSkipToItem(createRemoteUserInfo(packageName, pid, uid, caller), id);
+            }
+        }
+
+        @Override
+        public void onPause(String packageName, int pid, int uid,
+                ISessionControllerCallback caller) {
+            MediaSession session = mMediaSession.get();
+            if (session != null) {
+                session.dispatchPause(createRemoteUserInfo(packageName, pid, uid, caller));
+            }
+        }
+
+        @Override
+        public void onStop(String packageName, int pid, int uid,
+                ISessionControllerCallback caller) {
+            MediaSession session = mMediaSession.get();
+            if (session != null) {
+                session.dispatchStop(createRemoteUserInfo(packageName, pid, uid, caller));
+            }
+        }
+
+        @Override
+        public void onNext(String packageName, int pid, int uid,
+                ISessionControllerCallback caller) {
+            MediaSession session = mMediaSession.get();
+            if (session != null) {
+                session.dispatchNext(createRemoteUserInfo(packageName, pid, uid, caller));
+            }
+        }
+
+        @Override
+        public void onPrevious(String packageName, int pid, int uid,
+                ISessionControllerCallback caller) {
+            MediaSession session = mMediaSession.get();
+            if (session != null) {
+                session.dispatchPrevious(createRemoteUserInfo(packageName, pid, uid, caller));
+            }
+        }
+
+        @Override
+        public void onFastForward(String packageName, int pid, int uid,
+                ISessionControllerCallback caller) {
+            MediaSession session = mMediaSession.get();
+            if (session != null) {
+                session.dispatchFastForward(createRemoteUserInfo(packageName, pid, uid, caller));
+            }
+        }
+
+        @Override
+        public void onRewind(String packageName, int pid, int uid,
+                ISessionControllerCallback caller) {
+            MediaSession session = mMediaSession.get();
+            if (session != null) {
+                session.dispatchRewind(createRemoteUserInfo(packageName, pid, uid, caller));
+            }
+        }
+
+        @Override
+        public void onSeekTo(String packageName, int pid, int uid,
+                ISessionControllerCallback caller, long pos) {
+            MediaSession session = mMediaSession.get();
+            if (session != null) {
+                session.dispatchSeekTo(createRemoteUserInfo(packageName, pid, uid, caller), pos);
+            }
+        }
+
+        @Override
+        public void onRate(String packageName, int pid, int uid, ISessionControllerCallback caller,
+                Rating rating) {
+            MediaSession session = mMediaSession.get();
+            if (session != null) {
+                session.dispatchRate(createRemoteUserInfo(packageName, pid, uid, caller), rating);
+            }
+        }
+
+        @Override
+        public void onCustomAction(String packageName, int pid, int uid,
+                ISessionControllerCallback caller, String action, Bundle args) {
+            MediaSession session = mMediaSession.get();
+            if (session != null) {
+                session.dispatchCustomAction(createRemoteUserInfo(packageName, pid, uid, caller),
+                        action, args);
+            }
+        }
+
+        @Override
+        public void onAdjustVolume(String packageName, int pid, int uid,
+                ISessionControllerCallback caller, int direction) {
+            MediaSession session = mMediaSession.get();
+            if (session != null) {
+                session.dispatchAdjustVolume(createRemoteUserInfo(packageName, pid, uid, caller),
+                        direction);
+            }
+        }
+
+        @Override
+        public void onSetVolumeTo(String packageName, int pid, int uid,
+                ISessionControllerCallback caller, int value) {
+            MediaSession session = mMediaSession.get();
+            if (session != null) {
+                session.dispatchSetVolumeTo(createRemoteUserInfo(packageName, pid, uid, caller),
+                        value);
+            }
+        }
+    }
+
+    /**
+     * A single item that is part of the play queue. It contains a description
+     * of the item and its id in the queue.
+     */
+    public static final class QueueItem implements Parcelable {
+        /**
+         * This id is reserved. No items can be explicitly assigned this id.
+         */
+        public static final int UNKNOWN_ID = -1;
+
+        private final MediaDescription mDescription;
+        @UnsupportedAppUsage
+        private final long mId;
+
+        /**
+         * Create a new {@link MediaSession.QueueItem}.
+         *
+         * @param description The {@link MediaDescription} for this item.
+         * @param id An identifier for this item. It must be unique within the
+         *            play queue and cannot be {@link #UNKNOWN_ID}.
+         */
+        public QueueItem(MediaDescription description, long id) {
+            if (description == null) {
+                throw new IllegalArgumentException("Description cannot be null.");
+            }
+            if (id == UNKNOWN_ID) {
+                throw new IllegalArgumentException("Id cannot be QueueItem.UNKNOWN_ID");
+            }
+            mDescription = description;
+            mId = id;
+        }
+
+        private QueueItem(Parcel in) {
+            mDescription = MediaDescription.CREATOR.createFromParcel(in);
+            mId = in.readLong();
+        }
+
+        /**
+         * Get the description for this item.
+         */
+        public MediaDescription getDescription() {
+            return mDescription;
+        }
+
+        /**
+         * Get the queue id for this item.
+         */
+        public long getQueueId() {
+            return mId;
+        }
+
+        @Override
+        public void writeToParcel(Parcel dest, int flags) {
+            mDescription.writeToParcel(dest, flags);
+            dest.writeLong(mId);
+        }
+
+        @Override
+        public int describeContents() {
+            return 0;
+        }
+
+        public static final Creator<MediaSession.QueueItem> CREATOR =
+                new Creator<MediaSession.QueueItem>() {
+
+            @Override
+            public MediaSession.QueueItem createFromParcel(Parcel p) {
+                return new MediaSession.QueueItem(p);
+            }
+
+            @Override
+            public MediaSession.QueueItem[] newArray(int size) {
+                return new MediaSession.QueueItem[size];
+            }
+        };
+
+        @Override
+        public String toString() {
+            return "MediaSession.QueueItem {" +
+                    "Description=" + mDescription +
+                    ", Id=" + mId + " }";
+        }
+
+        @Override
+        public boolean equals(Object o) {
+            if (o == null) {
+                return false;
+            }
+
+            if (!(o instanceof QueueItem)) {
+                return false;
+            }
+
+            final QueueItem item = (QueueItem) o;
+            if (mId != item.mId) {
+                return false;
+            }
+
+            if (!Objects.equals(mDescription, item.mDescription)) {
+                return false;
+            }
+
+            return true;
+        }
+    }
+
+    private static final class Command {
+        public final String command;
+        public final Bundle extras;
+        public final ResultReceiver stub;
+
+        public Command(String command, Bundle extras, ResultReceiver stub) {
+            this.command = command;
+            this.extras = extras;
+            this.stub = stub;
+        }
+    }
+
+    private class CallbackMessageHandler extends Handler {
+        private static final int MSG_COMMAND = 1;
+        private static final int MSG_MEDIA_BUTTON = 2;
+        private static final int MSG_PREPARE = 3;
+        private static final int MSG_PREPARE_MEDIA_ID = 4;
+        private static final int MSG_PREPARE_SEARCH = 5;
+        private static final int MSG_PREPARE_URI = 6;
+        private static final int MSG_PLAY = 7;
+        private static final int MSG_PLAY_MEDIA_ID = 8;
+        private static final int MSG_PLAY_SEARCH = 9;
+        private static final int MSG_PLAY_URI = 10;
+        private static final int MSG_SKIP_TO_ITEM = 11;
+        private static final int MSG_PAUSE = 12;
+        private static final int MSG_STOP = 13;
+        private static final int MSG_NEXT = 14;
+        private static final int MSG_PREVIOUS = 15;
+        private static final int MSG_FAST_FORWARD = 16;
+        private static final int MSG_REWIND = 17;
+        private static final int MSG_SEEK_TO = 18;
+        private static final int MSG_RATE = 19;
+        private static final int MSG_CUSTOM_ACTION = 20;
+        private static final int MSG_ADJUST_VOLUME = 21;
+        private static final int MSG_SET_VOLUME = 22;
+        private static final int MSG_PLAY_PAUSE_KEY_DOUBLE_TAP_TIMEOUT = 23;
+
+        private MediaSession.Callback mCallback;
+        private RemoteUserInfo mCurrentControllerInfo;
+
+        public CallbackMessageHandler(Looper looper, MediaSession.Callback callback) {
+            super(looper, null, true);
+            mCallback = callback;
+            mCallback.mHandler = this;
+        }
+
+        public void post(RemoteUserInfo caller, int what, Object obj, Bundle data, long delayMs) {
+            Pair<RemoteUserInfo, Object> objWithCaller = Pair.create(caller, obj);
+            Message msg = obtainMessage(what, objWithCaller);
+            msg.setData(data);
+            if (delayMs > 0) {
+                sendMessageDelayed(msg, delayMs);
+            } else {
+                sendMessage(msg);
+            }
+        }
+
+        @Override
+        public void handleMessage(Message msg) {
+            mCurrentControllerInfo = ((Pair<RemoteUserInfo, Object>) msg.obj).first;
+
+            VolumeProvider vp;
+            Object obj = ((Pair<RemoteUserInfo, Object>) msg.obj).second;
+
+            switch (msg.what) {
+                case MSG_COMMAND:
+                    Command cmd = (Command) obj;
+                    mCallback.onCommand(cmd.command, cmd.extras, cmd.stub);
+                    break;
+                case MSG_MEDIA_BUTTON:
+                    mCallback.onMediaButtonEvent((Intent) obj);
+                    break;
+                case MSG_PREPARE:
+                    mCallback.onPrepare();
+                    break;
+                case MSG_PREPARE_MEDIA_ID:
+                    mCallback.onPrepareFromMediaId((String) obj, msg.getData());
+                    break;
+                case MSG_PREPARE_SEARCH:
+                    mCallback.onPrepareFromSearch((String) obj, msg.getData());
+                    break;
+                case MSG_PREPARE_URI:
+                    mCallback.onPrepareFromUri((Uri) obj, msg.getData());
+                    break;
+                case MSG_PLAY:
+                    mCallback.onPlay();
+                    break;
+                case MSG_PLAY_MEDIA_ID:
+                    mCallback.onPlayFromMediaId((String) obj, msg.getData());
+                    break;
+                case MSG_PLAY_SEARCH:
+                    mCallback.onPlayFromSearch((String) obj, msg.getData());
+                    break;
+                case MSG_PLAY_URI:
+                    mCallback.onPlayFromUri((Uri) obj, msg.getData());
+                    break;
+                case MSG_SKIP_TO_ITEM:
+                    mCallback.onSkipToQueueItem((Long) obj);
+                    break;
+                case MSG_PAUSE:
+                    mCallback.onPause();
+                    break;
+                case MSG_STOP:
+                    mCallback.onStop();
+                    break;
+                case MSG_NEXT:
+                    mCallback.onSkipToNext();
+                    break;
+                case MSG_PREVIOUS:
+                    mCallback.onSkipToPrevious();
+                    break;
+                case MSG_FAST_FORWARD:
+                    mCallback.onFastForward();
+                    break;
+                case MSG_REWIND:
+                    mCallback.onRewind();
+                    break;
+                case MSG_SEEK_TO:
+                    mCallback.onSeekTo((Long) obj);
+                    break;
+                case MSG_RATE:
+                    mCallback.onSetRating((Rating) obj);
+                    break;
+                case MSG_CUSTOM_ACTION:
+                    mCallback.onCustomAction((String) obj, msg.getData());
+                    break;
+                case MSG_ADJUST_VOLUME:
+                    synchronized (mLock) {
+                        vp = mVolumeProvider;
+                    }
+                    if (vp != null) {
+                        vp.onAdjustVolume((int) obj);
+                    }
+                    break;
+                case MSG_SET_VOLUME:
+                    synchronized (mLock) {
+                        vp = mVolumeProvider;
+                    }
+                    if (vp != null) {
+                        vp.onSetVolumeTo((int) obj);
+                    }
+                    break;
+                case MSG_PLAY_PAUSE_KEY_DOUBLE_TAP_TIMEOUT:
+                    mCallback.handleMediaPlayPauseKeySingleTapIfPending();
+                    break;
+            }
+            mCurrentControllerInfo = null;
+        }
+    }
+}
diff --git a/packages/MediaComponents/apex/java/android/media/session/ParcelableVolumeInfo.aidl b/packages/MediaComponents/apex/java/android/media/session/ParcelableVolumeInfo.aidl
new file mode 100644
index 0000000..c4250f0
--- /dev/null
+++ b/packages/MediaComponents/apex/java/android/media/session/ParcelableVolumeInfo.aidl
@@ -0,0 +1,18 @@
+/* Copyright 2014, The Android Open Source Project
+**
+** Licensed under the Apache License, Version 2.0 (the "License");
+** you may not use this file except in compliance with the License.
+** You may obtain a copy of the License at
+**
+**     http://www.apache.org/licenses/LICENSE-2.0
+**
+** Unless required by applicable law or agreed to in writing, software
+** distributed under the License is distributed on an "AS IS" BASIS,
+** WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+** See the License for the specific language governing permissions and
+** limitations under the License.
+*/
+
+package android.media.session;
+
+parcelable ParcelableVolumeInfo;
diff --git a/packages/MediaComponents/apex/java/android/media/session/ParcelableVolumeInfo.java b/packages/MediaComponents/apex/java/android/media/session/ParcelableVolumeInfo.java
new file mode 100644
index 0000000..f59c975
--- /dev/null
+++ b/packages/MediaComponents/apex/java/android/media/session/ParcelableVolumeInfo.java
@@ -0,0 +1,80 @@
+/* Copyright 2014, The Android Open Source Project
+ **
+ ** Licensed under the Apache License, Version 2.0 (the "License");
+ ** you may not use this file except in compliance with the License.
+ ** You may obtain a copy of the License at
+ **
+ **     http://www.apache.org/licenses/LICENSE-2.0
+ **
+ ** Unless required by applicable law or agreed to in writing, software
+ ** distributed under the License is distributed on an "AS IS" BASIS,
+ ** WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ ** See the License for the specific language governing permissions and
+ ** limitations under the License.
+ */
+
+package android.media.session;
+
+import android.media.AudioAttributes;
+import android.os.Parcel;
+import android.os.Parcelable;
+
+/**
+ * Convenience class for passing information about the audio configuration of a
+ * session. The public implementation is {@link MediaController.PlaybackInfo}.
+ *
+ * @hide
+ */
+public class ParcelableVolumeInfo implements Parcelable {
+    public int volumeType;
+    public AudioAttributes audioAttrs;
+    public int controlType;
+    public int maxVolume;
+    public int currentVolume;
+
+    public ParcelableVolumeInfo(int volumeType, AudioAttributes audioAttrs, int controlType,
+            int maxVolume,
+            int currentVolume) {
+        this.volumeType = volumeType;
+        this.audioAttrs = audioAttrs;
+        this.controlType = controlType;
+        this.maxVolume = maxVolume;
+        this.currentVolume = currentVolume;
+    }
+
+    public ParcelableVolumeInfo(Parcel from) {
+        volumeType = from.readInt();
+        controlType = from.readInt();
+        maxVolume = from.readInt();
+        currentVolume = from.readInt();
+        audioAttrs = AudioAttributes.CREATOR.createFromParcel(from);
+    }
+
+    @Override
+    public int describeContents() {
+        return 0;
+    }
+
+    @Override
+    public void writeToParcel(Parcel dest, int flags) {
+        dest.writeInt(volumeType);
+        dest.writeInt(controlType);
+        dest.writeInt(maxVolume);
+        dest.writeInt(currentVolume);
+        audioAttrs.writeToParcel(dest, flags);
+    }
+
+
+    public static final Parcelable.Creator<ParcelableVolumeInfo> CREATOR
+            = new Parcelable.Creator<ParcelableVolumeInfo>() {
+        @Override
+        public ParcelableVolumeInfo createFromParcel(Parcel in) {
+            return new ParcelableVolumeInfo(in);
+        }
+
+        @Override
+        public ParcelableVolumeInfo[] newArray(int size) {
+            return new ParcelableVolumeInfo[size];
+        }
+    };
+}
diff --git a/packages/MediaComponents/apex/java/android/media/session/PlaybackState.aidl b/packages/MediaComponents/apex/java/android/media/session/PlaybackState.aidl
new file mode 100644
index 0000000..0876ebd
--- /dev/null
+++ b/packages/MediaComponents/apex/java/android/media/session/PlaybackState.aidl
@@ -0,0 +1,18 @@
+/* Copyright 2014, The Android Open Source Project
+**
+** Licensed under the Apache License, Version 2.0 (the "License");
+** you may not use this file except in compliance with the License.
+** You may obtain a copy of the License at
+**
+**     http://www.apache.org/licenses/LICENSE-2.0
+**
+** Unless required by applicable law or agreed to in writing, software
+** distributed under the License is distributed on an "AS IS" BASIS,
+** WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+** See the License for the specific language governing permissions and
+** limitations under the License.
+*/
+
+package android.media.session;
+
+parcelable PlaybackState;
diff --git a/packages/MediaComponents/apex/java/android/media/session/PlaybackState.java b/packages/MediaComponents/apex/java/android/media/session/PlaybackState.java
new file mode 100644
index 0000000..17d16b8
--- /dev/null
+++ b/packages/MediaComponents/apex/java/android/media/session/PlaybackState.java
@@ -0,0 +1,1079 @@
+/*
+ * Copyright (C) 2014 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package android.media.session;
+
+import android.annotation.DrawableRes;
+import android.annotation.IntDef;
+import android.annotation.LongDef;
+import android.annotation.Nullable;
+import android.media.RemoteControlClient;
+import android.os.Bundle;
+import android.os.Parcel;
+import android.os.Parcelable;
+import android.os.SystemClock;
+import android.text.TextUtils;
+import java.util.ArrayList;
+import java.util.List;
+
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+
+/**
+ * Playback state for a {@link MediaSession}. This includes a state like
+ * {@link PlaybackState#STATE_PLAYING}, the current playback position,
+ * and the current control capabilities.
+ */
+public final class PlaybackState implements Parcelable {
+    private static final String TAG = "PlaybackState";
+
+    /**
+     * @hide
+     */
+    @LongDef(flag=true, value={ACTION_STOP, ACTION_PAUSE, ACTION_PLAY, ACTION_REWIND,
+            ACTION_SKIP_TO_PREVIOUS, ACTION_SKIP_TO_NEXT, ACTION_FAST_FORWARD, ACTION_SET_RATING,
+            ACTION_SEEK_TO, ACTION_PLAY_PAUSE, ACTION_PLAY_FROM_MEDIA_ID, ACTION_PLAY_FROM_SEARCH,
+            ACTION_SKIP_TO_QUEUE_ITEM, ACTION_PLAY_FROM_URI, ACTION_PREPARE,
+            ACTION_PREPARE_FROM_MEDIA_ID, ACTION_PREPARE_FROM_SEARCH, ACTION_PREPARE_FROM_URI})
+    @Retention(RetentionPolicy.SOURCE)
+    public @interface Actions {}
+
+    /**
+     * Indicates this session supports the stop command.
+     *
+     * @see Builder#setActions(long)
+     */
+    public static final long ACTION_STOP = 1 << 0;
+
+    /**
+     * Indicates this session supports the pause command.
+     *
+     * @see Builder#setActions(long)
+     */
+    public static final long ACTION_PAUSE = 1 << 1;
+
+    /**
+     * Indicates this session supports the play command.
+     *
+     * @see Builder#setActions(long)
+     */
+    public static final long ACTION_PLAY = 1 << 2;
+
+    /**
+     * Indicates this session supports the rewind command.
+     *
+     * @see Builder#setActions(long)
+     */
+    public static final long ACTION_REWIND = 1 << 3;
+
+    /**
+     * Indicates this session supports the previous command.
+     *
+     * @see Builder#setActions(long)
+     */
+    public static final long ACTION_SKIP_TO_PREVIOUS = 1 << 4;
+
+    /**
+     * Indicates this session supports the next command.
+     *
+     * @see Builder#setActions(long)
+     */
+    public static final long ACTION_SKIP_TO_NEXT = 1 << 5;
+
+    /**
+     * Indicates this session supports the fast forward command.
+     *
+     * @see Builder#setActions(long)
+     */
+    public static final long ACTION_FAST_FORWARD = 1 << 6;
+
+    /**
+     * Indicates this session supports the set rating command.
+     *
+     * @see Builder#setActions(long)
+     */
+    public static final long ACTION_SET_RATING = 1 << 7;
+
+    /**
+     * Indicates this session supports the seek to command.
+     *
+     * @see Builder#setActions(long)
+     */
+    public static final long ACTION_SEEK_TO = 1 << 8;
+
+    /**
+     * Indicates this session supports the play/pause toggle command.
+     *
+     * @see Builder#setActions(long)
+     */
+    public static final long ACTION_PLAY_PAUSE = 1 << 9;
+
+    /**
+     * Indicates this session supports the play from media id command.
+     *
+     * @see Builder#setActions(long)
+     */
+    public static final long ACTION_PLAY_FROM_MEDIA_ID = 1 << 10;
+
+    /**
+     * Indicates this session supports the play from search command.
+     *
+     * @see Builder#setActions(long)
+     */
+    public static final long ACTION_PLAY_FROM_SEARCH = 1 << 11;
+
+    /**
+     * Indicates this session supports the skip to queue item command.
+     *
+     * @see Builder#setActions(long)
+     */
+    public static final long ACTION_SKIP_TO_QUEUE_ITEM = 1 << 12;
+
+    /**
+     * Indicates this session supports the play from URI command.
+     *
+     * @see Builder#setActions(long)
+     */
+    public static final long ACTION_PLAY_FROM_URI = 1 << 13;
+
+    /**
+     * Indicates this session supports the prepare command.
+     *
+     * @see Builder#setActions(long)
+     */
+    public static final long ACTION_PREPARE = 1 << 14;
+
+    /**
+     * Indicates this session supports the prepare from media id command.
+     *
+     * @see Builder#setActions(long)
+     */
+    public static final long ACTION_PREPARE_FROM_MEDIA_ID = 1 << 15;
+
+    /**
+     * Indicates this session supports the prepare from search command.
+     *
+     * @see Builder#setActions(long)
+     */
+    public static final long ACTION_PREPARE_FROM_SEARCH = 1 << 16;
+
+    /**
+     * Indicates this session supports the prepare from URI command.
+     *
+     * @see Builder#setActions(long)
+     */
+    public static final long ACTION_PREPARE_FROM_URI = 1 << 17;
+
+    /**
+     * @hide
+     */
+    @IntDef({STATE_NONE, STATE_STOPPED, STATE_PAUSED, STATE_PLAYING, STATE_FAST_FORWARDING,
+            STATE_REWINDING, STATE_BUFFERING, STATE_ERROR, STATE_CONNECTING,
+            STATE_SKIPPING_TO_PREVIOUS, STATE_SKIPPING_TO_NEXT, STATE_SKIPPING_TO_QUEUE_ITEM})
+    @Retention(RetentionPolicy.SOURCE)
+    public @interface State {}
+
+    /**
+     * This is the default playback state and indicates that no media has been
+     * added yet, or the performer has been reset and has no content to play.
+     *
+     * @see Builder#setState(int, long, float)
+     * @see Builder#setState(int, long, float, long)
+     */
+    public final static int STATE_NONE = 0;
+
+    /**
+     * State indicating this item is currently stopped.
+     *
+     * @see Builder#setState
+     */
+    public final static int STATE_STOPPED = 1;
+
+    /**
+     * State indicating this item is currently paused.
+     *
+     * @see Builder#setState
+     */
+    public final static int STATE_PAUSED = 2;
+
+    /**
+     * State indicating this item is currently playing.
+     *
+     * @see Builder#setState
+     */
+    public final static int STATE_PLAYING = 3;
+
+    /**
+     * State indicating this item is currently fast forwarding.
+     *
+     * @see Builder#setState
+     */
+    public final static int STATE_FAST_FORWARDING = 4;
+
+    /**
+     * State indicating this item is currently rewinding.
+     *
+     * @see Builder#setState
+     */
+    public final static int STATE_REWINDING = 5;
+
+    /**
+     * State indicating this item is currently buffering and will begin playing
+     * when enough data has buffered.
+     *
+     * @see Builder#setState
+     */
+    public final static int STATE_BUFFERING = 6;
+
+    /**
+     * State indicating this item is currently in an error state. The error
+     * message should also be set when entering this state.
+     *
+     * @see Builder#setState
+     */
+    public final static int STATE_ERROR = 7;
+
+    /**
+     * State indicating the class doing playback is currently connecting to a
+     * new destination.  Depending on the implementation you may return to the previous
+     * state when the connection finishes or enter {@link #STATE_NONE}.
+     * If the connection failed {@link #STATE_ERROR} should be used.
+     *
+     * @see Builder#setState
+     */
+    public final static int STATE_CONNECTING = 8;
+
+    /**
+     * State indicating the player is currently skipping to the previous item.
+     *
+     * @see Builder#setState
+     */
+    public final static int STATE_SKIPPING_TO_PREVIOUS = 9;
+
+    /**
+     * State indicating the player is currently skipping to the next item.
+     *
+     * @see Builder#setState
+     */
+    public final static int STATE_SKIPPING_TO_NEXT = 10;
+
+    /**
+     * State indicating the player is currently skipping to a specific item in
+     * the queue.
+     *
+     * @see Builder#setState
+     */
+    public final static int STATE_SKIPPING_TO_QUEUE_ITEM = 11;
+
+    /**
+     * Use this value for the position to indicate the position is not known.
+     */
+    public final static long PLAYBACK_POSITION_UNKNOWN = -1;
+
+    private final int mState;
+    private final long mPosition;
+    private final long mBufferedPosition;
+    private final float mSpeed;
+    private final long mActions;
+    private List<PlaybackState.CustomAction> mCustomActions;
+    private final CharSequence mErrorMessage;
+    private final long mUpdateTime;
+    private final long mActiveItemId;
+    private final Bundle mExtras;
+
+    private PlaybackState(int state, long position, long updateTime, float speed,
+            long bufferedPosition, long transportControls,
+            List<PlaybackState.CustomAction> customActions, long activeItemId,
+            CharSequence error, Bundle extras) {
+        mState = state;
+        mPosition = position;
+        mSpeed = speed;
+        mUpdateTime = updateTime;
+        mBufferedPosition = bufferedPosition;
+        mActions = transportControls;
+        mCustomActions = new ArrayList<>(customActions);
+        mActiveItemId = activeItemId;
+        mErrorMessage = error;
+        mExtras = extras;
+    }
+
+    private PlaybackState(Parcel in) {
+        mState = in.readInt();
+        mPosition = in.readLong();
+        mSpeed = in.readFloat();
+        mUpdateTime = in.readLong();
+        mBufferedPosition = in.readLong();
+        mActions = in.readLong();
+        mCustomActions = in.createTypedArrayList(CustomAction.CREATOR);
+        mActiveItemId = in.readLong();
+        mErrorMessage = in.readCharSequence();
+        mExtras = in.readBundle();
+    }
+
+    @Override
+    public String toString() {
+        StringBuilder bob = new StringBuilder("PlaybackState {");
+        bob.append("state=").append(mState);
+        bob.append(", position=").append(mPosition);
+        bob.append(", buffered position=").append(mBufferedPosition);
+        bob.append(", speed=").append(mSpeed);
+        bob.append(", updated=").append(mUpdateTime);
+        bob.append(", actions=").append(mActions);
+        bob.append(", custom actions=").append(mCustomActions);
+        bob.append(", active item id=").append(mActiveItemId);
+        bob.append(", error=").append(mErrorMessage);
+        bob.append("}");
+        return bob.toString();
+    }
+
+    @Override
+    public int describeContents() {
+        return 0;
+    }
+
+    @Override
+    public void writeToParcel(Parcel dest, int flags) {
+        dest.writeInt(mState);
+        dest.writeLong(mPosition);
+        dest.writeFloat(mSpeed);
+        dest.writeLong(mUpdateTime);
+        dest.writeLong(mBufferedPosition);
+        dest.writeLong(mActions);
+        dest.writeTypedList(mCustomActions);
+        dest.writeLong(mActiveItemId);
+        dest.writeCharSequence(mErrorMessage);
+        dest.writeBundle(mExtras);
+    }
+
+    /**
+     * Get the current state of playback. One of the following:
+     * <ul>
+     * <li> {@link PlaybackState#STATE_NONE}</li>
+     * <li> {@link PlaybackState#STATE_STOPPED}</li>
+     * <li> {@link PlaybackState#STATE_PLAYING}</li>
+     * <li> {@link PlaybackState#STATE_PAUSED}</li>
+     * <li> {@link PlaybackState#STATE_FAST_FORWARDING}</li>
+     * <li> {@link PlaybackState#STATE_REWINDING}</li>
+     * <li> {@link PlaybackState#STATE_BUFFERING}</li>
+     * <li> {@link PlaybackState#STATE_ERROR}</li>
+     * <li> {@link PlaybackState#STATE_CONNECTING}</li>
+     * <li> {@link PlaybackState#STATE_SKIPPING_TO_PREVIOUS}</li>
+     * <li> {@link PlaybackState#STATE_SKIPPING_TO_NEXT}</li>
+     * <li> {@link PlaybackState#STATE_SKIPPING_TO_QUEUE_ITEM}</li>
+     * </ul>
+     */
+    @State
+    public int getState() {
+        return mState;
+    }
+
+    /**
+     * Get the current playback position in ms.
+     */
+    public long getPosition() {
+        return mPosition;
+    }
+
+    /**
+     * Get the current buffered position in ms. This is the farthest playback
+     * point that can be reached from the current position using only buffered
+     * content.
+     */
+    public long getBufferedPosition() {
+        return mBufferedPosition;
+    }
+
+    /**
+     * Get the current playback speed as a multiple of normal playback. This
+     * should be negative when rewinding. A value of 1 means normal playback and
+     * 0 means paused.
+     *
+     * @return The current speed of playback.
+     */
+    public float getPlaybackSpeed() {
+        return mSpeed;
+    }
+
+    /**
+     * Get the current actions available on this session. This should use a
+     * bitmask of the available actions.
+     * <ul>
+     * <li> {@link PlaybackState#ACTION_SKIP_TO_PREVIOUS}</li>
+     * <li> {@link PlaybackState#ACTION_REWIND}</li>
+     * <li> {@link PlaybackState#ACTION_PLAY}</li>
+     * <li> {@link PlaybackState#ACTION_PAUSE}</li>
+     * <li> {@link PlaybackState#ACTION_STOP}</li>
+     * <li> {@link PlaybackState#ACTION_FAST_FORWARD}</li>
+     * <li> {@link PlaybackState#ACTION_SKIP_TO_NEXT}</li>
+     * <li> {@link PlaybackState#ACTION_SEEK_TO}</li>
+     * <li> {@link PlaybackState#ACTION_SET_RATING}</li>
+     * <li> {@link PlaybackState#ACTION_PLAY_PAUSE}</li>
+     * <li> {@link PlaybackState#ACTION_PLAY_FROM_MEDIA_ID}</li>
+     * <li> {@link PlaybackState#ACTION_PLAY_FROM_SEARCH}</li>
+     * <li> {@link PlaybackState#ACTION_SKIP_TO_QUEUE_ITEM}</li>
+     * <li> {@link PlaybackState#ACTION_PLAY_FROM_URI}</li>
+     * <li> {@link PlaybackState#ACTION_PREPARE}</li>
+     * <li> {@link PlaybackState#ACTION_PREPARE_FROM_MEDIA_ID}</li>
+     * <li> {@link PlaybackState#ACTION_PREPARE_FROM_SEARCH}</li>
+     * <li> {@link PlaybackState#ACTION_PREPARE_FROM_URI}</li>
+     * </ul>
+     */
+    @Actions
+    public long getActions() {
+        return mActions;
+    }
+
+    /**
+     * Get the list of custom actions.
+     */
+    public List<PlaybackState.CustomAction> getCustomActions() {
+        return mCustomActions;
+    }
+
+    /**
+     * Get a user readable error message. This should be set when the state is
+     * {@link PlaybackState#STATE_ERROR}.
+     */
+    public CharSequence getErrorMessage() {
+        return mErrorMessage;
+    }
+
+    /**
+     * Get the elapsed real time at which position was last updated. If the
+     * position has never been set this will return 0;
+     *
+     * @return The last time the position was updated.
+     */
+    public long getLastPositionUpdateTime() {
+        return mUpdateTime;
+    }
+
+    /**
+     * Get the id of the currently active item in the queue. If there is no
+     * queue or a queue is not supported by the session this will be
+     * {@link MediaSession.QueueItem#UNKNOWN_ID}.
+     *
+     * @return The id of the currently active item in the queue or
+     *         {@link MediaSession.QueueItem#UNKNOWN_ID}.
+     */
+    public long getActiveQueueItemId() {
+        return mActiveItemId;
+    }
+
+    /**
+     * Get any custom extras that were set on this playback state.
+     *
+     * @return The extras for this state or null.
+     */
+    public @Nullable Bundle getExtras() {
+        return mExtras;
+    }
+
+    /**
+     * Get the {@link PlaybackState} state for the given
+     * {@link RemoteControlClient} state.
+     *
+     * @param rccState The state used by {@link RemoteControlClient}.
+     * @return The equivalent state used by {@link PlaybackState}.
+     * @hide
+     */
+    public static int getStateFromRccState(int rccState) {
+        switch (rccState) {
+            case RemoteControlClient.PLAYSTATE_BUFFERING:
+                return STATE_BUFFERING;
+            case RemoteControlClient.PLAYSTATE_ERROR:
+                return STATE_ERROR;
+            case RemoteControlClient.PLAYSTATE_FAST_FORWARDING:
+                return STATE_FAST_FORWARDING;
+            case RemoteControlClient.PLAYSTATE_NONE:
+                return STATE_NONE;
+            case RemoteControlClient.PLAYSTATE_PAUSED:
+                return STATE_PAUSED;
+            case RemoteControlClient.PLAYSTATE_PLAYING:
+                return STATE_PLAYING;
+            case RemoteControlClient.PLAYSTATE_REWINDING:
+                return STATE_REWINDING;
+            case RemoteControlClient.PLAYSTATE_SKIPPING_BACKWARDS:
+                return STATE_SKIPPING_TO_PREVIOUS;
+            case RemoteControlClient.PLAYSTATE_SKIPPING_FORWARDS:
+                return STATE_SKIPPING_TO_NEXT;
+            case RemoteControlClient.PLAYSTATE_STOPPED:
+                return STATE_STOPPED;
+            default:
+                return -1;
+        }
+    }
+
+    /**
+     * Get the {@link RemoteControlClient} state for the given
+     * {@link PlaybackState} state.
+     *
+     * @param state The state used by {@link PlaybackState}.
+     * @return The equivalent state used by {@link RemoteControlClient}.
+     * @hide
+     */
+    public static int getRccStateFromState(int state) {
+        switch (state) {
+            case STATE_BUFFERING:
+                return RemoteControlClient.PLAYSTATE_BUFFERING;
+            case STATE_ERROR:
+                return RemoteControlClient.PLAYSTATE_ERROR;
+            case STATE_FAST_FORWARDING:
+                return RemoteControlClient.PLAYSTATE_FAST_FORWARDING;
+            case STATE_NONE:
+                return RemoteControlClient.PLAYSTATE_NONE;
+            case STATE_PAUSED:
+                return RemoteControlClient.PLAYSTATE_PAUSED;
+            case STATE_PLAYING:
+                return RemoteControlClient.PLAYSTATE_PLAYING;
+            case STATE_REWINDING:
+                return RemoteControlClient.PLAYSTATE_REWINDING;
+            case STATE_SKIPPING_TO_PREVIOUS:
+                return RemoteControlClient.PLAYSTATE_SKIPPING_BACKWARDS;
+            case STATE_SKIPPING_TO_NEXT:
+                return RemoteControlClient.PLAYSTATE_SKIPPING_FORWARDS;
+            case STATE_STOPPED:
+                return RemoteControlClient.PLAYSTATE_STOPPED;
+            default:
+                return -1;
+        }
+    }
+
+    /**
+     * @hide
+     */
+    public static long getActionsFromRccControlFlags(int rccFlags) {
+        long actions = 0;
+        long flag = 1;
+        while (flag <= rccFlags) {
+            if ((flag & rccFlags) != 0) {
+                actions |= getActionForRccFlag((int) flag);
+            }
+            flag = flag << 1;
+        }
+        return actions;
+    }
+
+    /**
+     * @hide
+     */
+    public static int getRccControlFlagsFromActions(long actions) {
+        int rccFlags = 0;
+        long action = 1;
+        while (action <= actions && action < Integer.MAX_VALUE) {
+            if ((action & actions) != 0) {
+                rccFlags |= getRccFlagForAction(action);
+            }
+            action = action << 1;
+        }
+        return rccFlags;
+    }
+
+    private static long getActionForRccFlag(int flag) {
+        switch (flag) {
+            case RemoteControlClient.FLAG_KEY_MEDIA_PREVIOUS:
+                return ACTION_SKIP_TO_PREVIOUS;
+            case RemoteControlClient.FLAG_KEY_MEDIA_REWIND:
+                return ACTION_REWIND;
+            case RemoteControlClient.FLAG_KEY_MEDIA_PLAY:
+                return ACTION_PLAY;
+            case RemoteControlClient.FLAG_KEY_MEDIA_PLAY_PAUSE:
+                return ACTION_PLAY_PAUSE;
+            case RemoteControlClient.FLAG_KEY_MEDIA_PAUSE:
+                return ACTION_PAUSE;
+            case RemoteControlClient.FLAG_KEY_MEDIA_STOP:
+                return ACTION_STOP;
+            case RemoteControlClient.FLAG_KEY_MEDIA_FAST_FORWARD:
+                return ACTION_FAST_FORWARD;
+            case RemoteControlClient.FLAG_KEY_MEDIA_NEXT:
+                return ACTION_SKIP_TO_NEXT;
+            case RemoteControlClient.FLAG_KEY_MEDIA_POSITION_UPDATE:
+                return ACTION_SEEK_TO;
+            case RemoteControlClient.FLAG_KEY_MEDIA_RATING:
+                return ACTION_SET_RATING;
+        }
+        return 0;
+    }
+
+    private static int getRccFlagForAction(long action) {
+        // We only care about the lower set of actions that can map to rcc
+        // flags.
+        int testAction = action < Integer.MAX_VALUE ? (int) action : 0;
+        switch (testAction) {
+            case (int) ACTION_SKIP_TO_PREVIOUS:
+                return RemoteControlClient.FLAG_KEY_MEDIA_PREVIOUS;
+            case (int) ACTION_REWIND:
+                return RemoteControlClient.FLAG_KEY_MEDIA_REWIND;
+            case (int) ACTION_PLAY:
+                return RemoteControlClient.FLAG_KEY_MEDIA_PLAY;
+            case (int) ACTION_PLAY_PAUSE:
+                return RemoteControlClient.FLAG_KEY_MEDIA_PLAY_PAUSE;
+            case (int) ACTION_PAUSE:
+                return RemoteControlClient.FLAG_KEY_MEDIA_PAUSE;
+            case (int) ACTION_STOP:
+                return RemoteControlClient.FLAG_KEY_MEDIA_STOP;
+            case (int) ACTION_FAST_FORWARD:
+                return RemoteControlClient.FLAG_KEY_MEDIA_FAST_FORWARD;
+            case (int) ACTION_SKIP_TO_NEXT:
+                return RemoteControlClient.FLAG_KEY_MEDIA_NEXT;
+            case (int) ACTION_SEEK_TO:
+                return RemoteControlClient.FLAG_KEY_MEDIA_POSITION_UPDATE;
+            case (int) ACTION_SET_RATING:
+                return RemoteControlClient.FLAG_KEY_MEDIA_RATING;
+        }
+        return 0;
+    }
+
+    public static final Parcelable.Creator<PlaybackState> CREATOR =
+            new Parcelable.Creator<PlaybackState>() {
+        @Override
+        public PlaybackState createFromParcel(Parcel in) {
+            return new PlaybackState(in);
+        }
+
+        @Override
+        public PlaybackState[] newArray(int size) {
+            return new PlaybackState[size];
+        }
+    };
+
+    /**
+     * {@link PlaybackState.CustomAction CustomActions} can be used to extend the capabilities of
+     * the standard transport controls by exposing app specific actions to
+     * {@link MediaController MediaControllers}.
+     */
+    public static final class CustomAction implements Parcelable {
+        private final String mAction;
+        private final CharSequence mName;
+        private final int mIcon;
+        private final Bundle mExtras;
+
+        /**
+         * Use {@link PlaybackState.CustomAction.Builder#build()}.
+         */
+        private CustomAction(String action, CharSequence name, int icon, Bundle extras) {
+            mAction = action;
+            mName = name;
+            mIcon = icon;
+            mExtras = extras;
+        }
+
+        private CustomAction(Parcel in) {
+            mAction = in.readString();
+            mName = TextUtils.CHAR_SEQUENCE_CREATOR.createFromParcel(in);
+            mIcon = in.readInt();
+            mExtras = in.readBundle();
+        }
+
+        @Override
+        public void writeToParcel(Parcel dest, int flags) {
+            dest.writeString(mAction);
+            TextUtils.writeToParcel(mName, dest, flags);
+            dest.writeInt(mIcon);
+            dest.writeBundle(mExtras);
+        }
+
+        @Override
+        public int describeContents() {
+            return 0;
+        }
+
+        public static final Parcelable.Creator<PlaybackState.CustomAction> CREATOR
+                = new Parcelable.Creator<PlaybackState.CustomAction>() {
+
+            @Override
+            public PlaybackState.CustomAction createFromParcel(Parcel p) {
+                return new PlaybackState.CustomAction(p);
+            }
+
+            @Override
+            public PlaybackState.CustomAction[] newArray(int size) {
+                return new PlaybackState.CustomAction[size];
+            }
+        };
+
+        /**
+         * Returns the action of the {@link CustomAction}.
+         *
+         * @return The action of the {@link CustomAction}.
+         */
+        public String getAction() {
+            return mAction;
+        }
+
+        /**
+         * Returns the display name of this action. e.g. "Favorite"
+         *
+         * @return The display name of this {@link CustomAction}.
+         */
+        public CharSequence getName() {
+            return mName;
+        }
+
+        /**
+         * Returns the resource id of the icon in the {@link MediaSession MediaSession's} package.
+         *
+         * @return The resource id of the icon in the {@link MediaSession MediaSession's} package.
+         */
+        public int getIcon() {
+            return mIcon;
+        }
+
+        /**
+         * Returns extras which provide additional application-specific information about the
+         * action, or null if none. These arguments are meant to be consumed by a
+         * {@link MediaController} if it knows how to handle them.
+         *
+         * @return Optional arguments for the {@link CustomAction}.
+         */
+        public Bundle getExtras() {
+            return mExtras;
+        }
+
+        @Override
+        public String toString() {
+            return "Action:" +
+                    "mName='" + mName +
+                    ", mIcon=" + mIcon +
+                    ", mExtras=" + mExtras;
+        }
+
+        /**
+         * Builder for {@link CustomAction} objects.
+         */
+        public static final class Builder {
+            private final String mAction;
+            private final CharSequence mName;
+            private final int mIcon;
+            private Bundle mExtras;
+
+            /**
+             * Creates a {@link CustomAction} builder with the id, name, and icon set.
+             *
+             * @param action The action of the {@link CustomAction}.
+             * @param name The display name of the {@link CustomAction}. This name will be displayed
+             *             along side the action if the UI supports it.
+             * @param icon The icon resource id of the {@link CustomAction}. This resource id
+             *             must be in the same package as the {@link MediaSession}. It will be
+             *             displayed with the custom action if the UI supports it.
+             */
+            public Builder(String action, CharSequence name, @DrawableRes int icon) {
+                if (TextUtils.isEmpty(action)) {
+                    throw new IllegalArgumentException(
+                            "You must specify an action to build a CustomAction.");
+                }
+                if (TextUtils.isEmpty(name)) {
+                    throw new IllegalArgumentException(
+                            "You must specify a name to build a CustomAction.");
+                }
+                if (icon == 0) {
+                    throw new IllegalArgumentException(
+                            "You must specify an icon resource id to build a CustomAction.");
+                }
+                mAction = action;
+                mName = name;
+                mIcon = icon;
+            }
+
+            /**
+             * Set optional extras for the {@link CustomAction}. These extras are meant to be
+             * consumed by a {@link MediaController} if it knows how to handle them.
+             * Keys should be fully qualified (e.g. "com.example.MY_ARG") to avoid collisions.
+             *
+             * @param extras Optional extras for the {@link CustomAction}.
+             * @return this.
+             */
+            public Builder setExtras(Bundle extras) {
+                mExtras = extras;
+                return this;
+            }
+
+            /**
+             * Build and return the {@link CustomAction} instance with the specified values.
+             *
+             * @return A new {@link CustomAction} instance.
+             */
+            public CustomAction build() {
+                return new CustomAction(mAction, mName, mIcon, mExtras);
+            }
+        }
+    }
+
+    /**
+     * Builder for {@link PlaybackState} objects.
+     */
+    public static final class Builder {
+        private final List<PlaybackState.CustomAction> mCustomActions = new ArrayList<>();
+
+        private int mState;
+        private long mPosition;
+        private long mBufferedPosition;
+        private float mSpeed;
+        private long mActions;
+        private CharSequence mErrorMessage;
+        private long mUpdateTime;
+        private long mActiveItemId = MediaSession.QueueItem.UNKNOWN_ID;
+        private Bundle mExtras;
+
+        /**
+         * Creates an initially empty state builder.
+         */
+        public Builder() {
+        }
+
+        /**
+         * Creates a builder with the same initial values as those in the from
+         * state.
+         *
+         * @param from The state to use for initializing the builder.
+         */
+        public Builder(PlaybackState from) {
+            if (from == null) {
+                return;
+            }
+            mState = from.mState;
+            mPosition = from.mPosition;
+            mBufferedPosition = from.mBufferedPosition;
+            mSpeed = from.mSpeed;
+            mActions = from.mActions;
+            if (from.mCustomActions != null) {
+                mCustomActions.addAll(from.mCustomActions);
+            }
+            mErrorMessage = from.mErrorMessage;
+            mUpdateTime = from.mUpdateTime;
+            mActiveItemId = from.mActiveItemId;
+            mExtras = from.mExtras;
+        }
+
+        /**
+         * Set the current state of playback.
+         * <p>
+         * The position must be in ms and indicates the current playback
+         * position within the item. If the position is unknown use
+         * {@link #PLAYBACK_POSITION_UNKNOWN}. When not using an unknown
+         * position the time at which the position was updated must be provided.
+         * It is okay to use {@link SystemClock#elapsedRealtime()} if the
+         * current position was just retrieved.
+         * <p>
+         * The speed is a multiple of normal playback and should be 0 when
+         * paused and negative when rewinding. Normal playback speed is 1.0.
+         * <p>
+         * The state must be one of the following:
+         * <ul>
+         * <li> {@link PlaybackState#STATE_NONE}</li>
+         * <li> {@link PlaybackState#STATE_STOPPED}</li>
+         * <li> {@link PlaybackState#STATE_PLAYING}</li>
+         * <li> {@link PlaybackState#STATE_PAUSED}</li>
+         * <li> {@link PlaybackState#STATE_FAST_FORWARDING}</li>
+         * <li> {@link PlaybackState#STATE_REWINDING}</li>
+         * <li> {@link PlaybackState#STATE_BUFFERING}</li>
+         * <li> {@link PlaybackState#STATE_ERROR}</li>
+         * <li> {@link PlaybackState#STATE_CONNECTING}</li>
+         * <li> {@link PlaybackState#STATE_SKIPPING_TO_PREVIOUS}</li>
+         * <li> {@link PlaybackState#STATE_SKIPPING_TO_NEXT}</li>
+         * <li> {@link PlaybackState#STATE_SKIPPING_TO_QUEUE_ITEM}</li>
+         * </ul>
+         *
+         * @param state The current state of playback.
+         * @param position The position in the current item in ms.
+         * @param playbackSpeed The current speed of playback as a multiple of
+         *            normal playback.
+         * @param updateTime The time in the {@link SystemClock#elapsedRealtime}
+         *            timebase that the position was updated at.
+         * @return this
+         */
+        public Builder setState(@State int state, long position, float playbackSpeed,
+                long updateTime) {
+            mState = state;
+            mPosition = position;
+            mUpdateTime = updateTime;
+            mSpeed = playbackSpeed;
+            return this;
+        }
+
+        /**
+         * Set the current state of playback.
+         * <p>
+         * The position must be in ms and indicates the current playback
+         * position within the item. If the position is unknown use
+         * {@link #PLAYBACK_POSITION_UNKNOWN}. The update time will be set to
+         * the current {@link SystemClock#elapsedRealtime()}.
+         * <p>
+         * The speed is a multiple of normal playback and should be 0 when
+         * paused and negative when rewinding. Normal playback speed is 1.0.
+         * <p>
+         * The state must be one of the following:
+         * <ul>
+         * <li> {@link PlaybackState#STATE_NONE}</li>
+         * <li> {@link PlaybackState#STATE_STOPPED}</li>
+         * <li> {@link PlaybackState#STATE_PLAYING}</li>
+         * <li> {@link PlaybackState#STATE_PAUSED}</li>
+         * <li> {@link PlaybackState#STATE_FAST_FORWARDING}</li>
+         * <li> {@link PlaybackState#STATE_REWINDING}</li>
+         * <li> {@link PlaybackState#STATE_BUFFERING}</li>
+         * <li> {@link PlaybackState#STATE_ERROR}</li>
+         * <li> {@link PlaybackState#STATE_CONNECTING}</li>
+         * <li> {@link PlaybackState#STATE_SKIPPING_TO_PREVIOUS}</li>
+         * <li> {@link PlaybackState#STATE_SKIPPING_TO_NEXT}</li>
+         * <li> {@link PlaybackState#STATE_SKIPPING_TO_QUEUE_ITEM}</li>
+         * </ul>
+         *
+         * @param state The current state of playback.
+         * @param position The position in the current item in ms.
+         * @param playbackSpeed The current speed of playback as a multiple of
+         *            normal playback.
+         * @return this
+         */
+        public Builder setState(@State int state, long position, float playbackSpeed) {
+            return setState(state, position, playbackSpeed, SystemClock.elapsedRealtime());
+        }
+
+        /**
+         * Set the current actions available on this session. This should use a
+         * bitmask of possible actions.
+         * <ul>
+         * <li> {@link PlaybackState#ACTION_SKIP_TO_PREVIOUS}</li>
+         * <li> {@link PlaybackState#ACTION_REWIND}</li>
+         * <li> {@link PlaybackState#ACTION_PLAY}</li>
+         * <li> {@link PlaybackState#ACTION_PAUSE}</li>
+         * <li> {@link PlaybackState#ACTION_STOP}</li>
+         * <li> {@link PlaybackState#ACTION_FAST_FORWARD}</li>
+         * <li> {@link PlaybackState#ACTION_SKIP_TO_NEXT}</li>
+         * <li> {@link PlaybackState#ACTION_SEEK_TO}</li>
+         * <li> {@link PlaybackState#ACTION_SET_RATING}</li>
+         * <li> {@link PlaybackState#ACTION_PLAY_PAUSE}</li>
+         * <li> {@link PlaybackState#ACTION_PLAY_FROM_MEDIA_ID}</li>
+         * <li> {@link PlaybackState#ACTION_PLAY_FROM_SEARCH}</li>
+         * <li> {@link PlaybackState#ACTION_SKIP_TO_QUEUE_ITEM}</li>
+         * <li> {@link PlaybackState#ACTION_PLAY_FROM_URI}</li>
+         * <li> {@link PlaybackState#ACTION_PREPARE}</li>
+         * <li> {@link PlaybackState#ACTION_PREPARE_FROM_MEDIA_ID}</li>
+         * <li> {@link PlaybackState#ACTION_PREPARE_FROM_SEARCH}</li>
+         * <li> {@link PlaybackState#ACTION_PREPARE_FROM_URI}</li>
+         * </ul>
+         *
+         * @param actions The set of actions allowed.
+         * @return this
+         */
+        public Builder setActions(@Actions long actions) {
+            mActions = actions;
+            return this;
+        }
+
+        /**
+         * Add a custom action to the playback state. Actions can be used to
+         * expose additional functionality to {@link MediaController
+         * MediaControllers} beyond what is offered by the standard transport
+         * controls.
+         * <p>
+         * e.g. start a radio station based on the current item or skip ahead by
+         * 30 seconds.
+         *
+         * @param action An identifier for this action. It can be sent back to
+         *            the {@link MediaSession} through
+         *            {@link MediaController.TransportControls#sendCustomAction(String, Bundle)}.
+         * @param name The display name for the action. If text is shown with
+         *            the action or used for accessibility, this is what should
+         *            be used.
+         * @param icon The resource action of the icon that should be displayed
+         *            for the action. The resource should be in the package of
+         *            the {@link MediaSession}.
+         * @return this
+         */
+        public Builder addCustomAction(String action, String name, int icon) {
+            return addCustomAction(new PlaybackState.CustomAction(action, name, icon, null));
+        }
+
+        /**
+         * Add a custom action to the playback state. Actions can be used to expose additional
+         * functionality to {@link MediaController MediaControllers} beyond what is offered by the
+         * standard transport controls.
+         * <p>
+         * An example of an action would be to start a radio station based on the current item
+         * or to skip ahead by 30 seconds.
+         *
+         * @param customAction The custom action to add to the {@link PlaybackState}.
+         * @return this
+         */
+        public Builder addCustomAction(PlaybackState.CustomAction customAction) {
+            if (customAction == null) {
+                throw new IllegalArgumentException(
+                        "You may not add a null CustomAction to PlaybackState.");
+            }
+            mCustomActions.add(customAction);
+            return this;
+        }
+
+        /**
+         * Set the current buffered position in ms. This is the farthest
+         * playback point that can be reached from the current position using
+         * only buffered content.
+         *
+         * @param bufferedPosition The position in ms that playback is buffered
+         *            to.
+         * @return this
+         */
+        public Builder setBufferedPosition(long bufferedPosition) {
+            mBufferedPosition = bufferedPosition;
+            return this;
+        }
+
+        /**
+         * Set the active item in the play queue by specifying its id. The
+         * default value is {@link MediaSession.QueueItem#UNKNOWN_ID}
+         *
+         * @param id The id of the active item.
+         * @return this
+         */
+        public Builder setActiveQueueItemId(long id) {
+            mActiveItemId = id;
+            return this;
+        }
+
+        /**
+         * Set a user readable error message. This should be set when the state
+         * is {@link PlaybackState#STATE_ERROR}.
+         *
+         * @param error The error message for display to the user.
+         * @return this
+         */
+        public Builder setErrorMessage(CharSequence error) {
+            mErrorMessage = error;
+            return this;
+        }
+
+        /**
+         * Set any custom extras to be included with the playback state.
+         *
+         * @param extras The extras to include.
+         * @return this
+         */
+        public Builder setExtras(Bundle extras) {
+            mExtras = extras;
+            return this;
+        }
+
+        /**
+         * Build and return the {@link PlaybackState} instance with these
+         * values.
+         *
+         * @return A new state instance.
+         */
+        public PlaybackState build() {
+            return new PlaybackState(mState, mPosition, mUpdateTime, mSpeed, mBufferedPosition,
+                    mActions, mCustomActions, mActiveItemId, mErrorMessage, mExtras);
+        }
+    }
+}
diff --git a/packages/MediaComponents/apex/java/android/service/media/IMediaBrowserService.aidl b/packages/MediaComponents/apex/java/android/service/media/IMediaBrowserService.aidl
new file mode 100644
index 0000000..84f41f6
--- /dev/null
+++ b/packages/MediaComponents/apex/java/android/service/media/IMediaBrowserService.aidl
@@ -0,0 +1,27 @@
+// Copyright 2014 Google Inc. All Rights Reserved.
+
+package android.service.media;
+
+import android.content.res.Configuration;
+import android.service.media.IMediaBrowserServiceCallbacks;
+import android.net.Uri;
+import android.os.Bundle;
+import android.os.ResultReceiver;
+
+/**
+ * Media API allows clients to browse through hierarchy of a user’s media collection,
+ * playback a specific media entry and interact with the now playing queue.
+ * @hide
+ */
+oneway interface IMediaBrowserService {
+    void connect(String pkg, in Bundle rootHints, IMediaBrowserServiceCallbacks callbacks);
+    void disconnect(IMediaBrowserServiceCallbacks callbacks);
+
+    void addSubscriptionDeprecated(String uri, IMediaBrowserServiceCallbacks callbacks);
+    void removeSubscriptionDeprecated(String uri, IMediaBrowserServiceCallbacks callbacks);
+
+    void getMediaItem(String uri, in ResultReceiver cb, IMediaBrowserServiceCallbacks callbacks);
+    void addSubscription(String uri, in IBinder token, in Bundle options,
+            IMediaBrowserServiceCallbacks callbacks);
+    void removeSubscription(String uri, in IBinder token, IMediaBrowserServiceCallbacks callbacks);
+}
diff --git a/packages/MediaComponents/apex/java/android/service/media/IMediaBrowserServiceCallbacks.aidl b/packages/MediaComponents/apex/java/android/service/media/IMediaBrowserServiceCallbacks.aidl
new file mode 100644
index 0000000..deeab1a
--- /dev/null
+++ b/packages/MediaComponents/apex/java/android/service/media/IMediaBrowserServiceCallbacks.aidl
@@ -0,0 +1,27 @@
+// Copyright 2014 Google Inc. All Rights Reserved.
+
+package android.service.media;
+
+import android.content.pm.ParceledListSlice;
+import android.graphics.Bitmap;
+import android.media.session.MediaSession;
+import android.os.Bundle;
+
+/**
+ * Media API allows clients to browse through hierarchy of a user’s media collection,
+ * playback a specific media entry and interact with the now playing queue.
+ * @hide
+ */
+oneway interface IMediaBrowserServiceCallbacks {
+    /**
+     * Invoked when the connected has been established.
+     * @param root The root media id for browsing.
+     * @param session The {@link MediaSession.Token media session token} that can be used to control
+     *         the playback of the media app.
+     * @param extra Extras returned by the media service.
+     */
+    void onConnect(String root, in MediaSession.Token session, in Bundle extras);
+    void onConnectFailed();
+    void onLoadChildren(String mediaId, in ParceledListSlice list);
+    void onLoadChildrenWithOptions(String mediaId, in ParceledListSlice list, in Bundle options);
+}
diff --git a/packages/MediaComponents/apex/java/android/service/media/MediaBrowserService.java b/packages/MediaComponents/apex/java/android/service/media/MediaBrowserService.java
new file mode 100644
index 0000000..2f2fbaf
--- /dev/null
+++ b/packages/MediaComponents/apex/java/android/service/media/MediaBrowserService.java
@@ -0,0 +1,864 @@
+/*
+ * Copyright (C) 2014 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package android.service.media;
+
+import android.annotation.IntDef;
+import android.annotation.NonNull;
+import android.annotation.Nullable;
+import android.annotation.SdkConstant;
+import android.annotation.SdkConstant.SdkConstantType;
+import android.annotation.UnsupportedAppUsage;
+import android.app.Service;
+import android.content.Intent;
+import android.content.pm.PackageManager;
+//import android.content.pm.ParceledListSlice;
+import android.media.browse.MediaBrowser;
+import android.media.browse.MediaBrowserUtils;
+import android.media.session.MediaSession;
+import android.os.Binder;
+import android.os.Bundle;
+import android.os.Handler;
+import android.media.session.MediaSessionManager;
+import android.media.session.MediaSessionManager.RemoteUserInfo;
+import android.os.IBinder;
+import android.os.RemoteException;
+import android.os.ResultReceiver;
+import android.service.media.IMediaBrowserService;
+import android.service.media.IMediaBrowserServiceCallbacks;
+import android.text.TextUtils;
+import android.util.ArrayMap;
+import android.util.Log;
+import android.util.Pair;
+
+import java.io.FileDescriptor;
+import java.io.PrintWriter;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.HashMap;
+import java.util.Iterator;
+import java.util.List;
+
+/**
+ * Base class for media browser services.
+ * <p>
+ * Media browser services enable applications to browse media content provided by an application
+ * and ask the application to start playing it. They may also be used to control content that
+ * is already playing by way of a {@link MediaSession}.
+ * </p>
+ *
+ * To extend this class, you must declare the service in your manifest file with
+ * an intent filter with the {@link #SERVICE_INTERFACE} action.
+ *
+ * For example:
+ * </p><pre>
+ * &lt;service android:name=".MyMediaBrowserService"
+ *          android:label="&#64;string/service_name" >
+ *     &lt;intent-filter>
+ *         &lt;action android:name="android.media.browse.MediaBrowserService" />
+ *     &lt;/intent-filter>
+ * &lt;/service>
+ * </pre>
+ *
+ */
+public abstract class MediaBrowserService extends Service {
+    private static final String TAG = "MediaBrowserService";
+    private static final boolean DBG = false;
+
+    /**
+     * The {@link Intent} that must be declared as handled by the service.
+     */
+    @SdkConstant(SdkConstantType.SERVICE_ACTION)
+    public static final String SERVICE_INTERFACE = "android.media.browse.MediaBrowserService";
+
+    /**
+     * A key for passing the MediaItem to the ResultReceiver in getItem.
+     * @hide
+     */
+    @UnsupportedAppUsage
+    public static final String KEY_MEDIA_ITEM = "media_item";
+
+    private static final int RESULT_FLAG_OPTION_NOT_HANDLED = 1 << 0;
+    private static final int RESULT_FLAG_ON_LOAD_ITEM_NOT_IMPLEMENTED = 1 << 1;
+
+    private static final int RESULT_ERROR = -1;
+    private static final int RESULT_OK = 0;
+
+    /** @hide */
+    @Retention(RetentionPolicy.SOURCE)
+    @IntDef(flag=true, value = { RESULT_FLAG_OPTION_NOT_HANDLED,
+            RESULT_FLAG_ON_LOAD_ITEM_NOT_IMPLEMENTED })
+    private @interface ResultFlags { }
+
+    private final ArrayMap<IBinder, ConnectionRecord> mConnections = new ArrayMap<>();
+    private ConnectionRecord mCurConnection;
+    private final Handler mHandler = new Handler();
+    private ServiceBinder mBinder;
+    MediaSession.Token mSession;
+
+    /**
+     * All the info about a connection.
+     */
+    private class ConnectionRecord implements IBinder.DeathRecipient {
+        String pkg;
+        int uid;
+        int pid;
+        Bundle rootHints;
+        IMediaBrowserServiceCallbacks callbacks;
+        BrowserRoot root;
+        HashMap<String, List<Pair<IBinder, Bundle>>> subscriptions = new HashMap<>();
+
+        @Override
+        public void binderDied() {
+            mHandler.post(new Runnable() {
+                @Override
+                public void run() {
+                    mConnections.remove(callbacks.asBinder());
+                }
+            });
+        }
+    }
+
+    /**
+     * Completion handler for asynchronous callback methods in {@link MediaBrowserService}.
+     * <p>
+     * Each of the methods that takes one of these to send the result must call
+     * {@link #sendResult} to respond to the caller with the given results. If those
+     * functions return without calling {@link #sendResult}, they must instead call
+     * {@link #detach} before returning, and then may call {@link #sendResult} when
+     * they are done. If more than one of those methods is called, an exception will
+     * be thrown.
+     *
+     * @see #onLoadChildren
+     * @see #onLoadItem
+     */
+    public class Result<T> {
+        private Object mDebug;
+        private boolean mDetachCalled;
+        private boolean mSendResultCalled;
+        @UnsupportedAppUsage
+        private int mFlags;
+
+        Result(Object debug) {
+            mDebug = debug;
+        }
+
+        /**
+         * Send the result back to the caller.
+         */
+        public void sendResult(T result) {
+            if (mSendResultCalled) {
+                throw new IllegalStateException("sendResult() called twice for: " + mDebug);
+            }
+            mSendResultCalled = true;
+            onResultSent(result, mFlags);
+        }
+
+        /**
+         * Detach this message from the current thread and allow the {@link #sendResult}
+         * call to happen later.
+         */
+        public void detach() {
+            if (mDetachCalled) {
+                throw new IllegalStateException("detach() called when detach() had already"
+                        + " been called for: " + mDebug);
+            }
+            if (mSendResultCalled) {
+                throw new IllegalStateException("detach() called when sendResult() had already"
+                        + " been called for: " + mDebug);
+            }
+            mDetachCalled = true;
+        }
+
+        boolean isDone() {
+            return mDetachCalled || mSendResultCalled;
+        }
+
+        void setFlags(@ResultFlags int flags) {
+            mFlags = flags;
+        }
+
+        /**
+         * Called when the result is sent, after assertions about not being called twice
+         * have happened.
+         */
+        void onResultSent(T result, @ResultFlags int flags) {
+        }
+    }
+
+    private class ServiceBinder extends IMediaBrowserService.Stub {
+        @Override
+        public void connect(final String pkg, final Bundle rootHints,
+                final IMediaBrowserServiceCallbacks callbacks) {
+
+            final int pid = Binder.getCallingPid();
+            final int uid = Binder.getCallingUid();
+            if (!isValidPackage(pkg, uid)) {
+                throw new IllegalArgumentException("Package/uid mismatch: uid=" + uid
+                        + " package=" + pkg);
+            }
+
+            mHandler.post(new Runnable() {
+                    @Override
+                    public void run() {
+                        final IBinder b = callbacks.asBinder();
+
+                        // Clear out the old subscriptions. We are getting new ones.
+                        mConnections.remove(b);
+
+                        final ConnectionRecord connection = new ConnectionRecord();
+                        connection.pkg = pkg;
+                        connection.pid = pid;
+                        connection.uid = uid;
+                        connection.rootHints = rootHints;
+                        connection.callbacks = callbacks;
+
+                        mCurConnection = connection;
+                        connection.root = MediaBrowserService.this.onGetRoot(pkg, uid, rootHints);
+                        mCurConnection = null;
+
+                        // If they didn't return something, don't allow this client.
+                        if (connection.root == null) {
+                            Log.i(TAG, "No root for client " + pkg + " from service "
+                                    + getClass().getName());
+                            try {
+                                callbacks.onConnectFailed();
+                            } catch (RemoteException ex) {
+                                Log.w(TAG, "Calling onConnectFailed() failed. Ignoring. "
+                                        + "pkg=" + pkg);
+                            }
+                        } else {
+                            try {
+                                mConnections.put(b, connection);
+                                b.linkToDeath(connection, 0);
+                                if (mSession != null) {
+                                    callbacks.onConnect(connection.root.getRootId(),
+                                            mSession, connection.root.getExtras());
+                                }
+                            } catch (RemoteException ex) {
+                                Log.w(TAG, "Calling onConnect() failed. Dropping client. "
+                                        + "pkg=" + pkg);
+                                mConnections.remove(b);
+                            }
+                        }
+                    }
+                });
+        }
+
+        @Override
+        public void disconnect(final IMediaBrowserServiceCallbacks callbacks) {
+            mHandler.post(new Runnable() {
+                    @Override
+                    public void run() {
+                        final IBinder b = callbacks.asBinder();
+
+                        // Clear out the old subscriptions. We are getting new ones.
+                        final ConnectionRecord old = mConnections.remove(b);
+                        if (old != null) {
+                            // TODO
+                            old.callbacks.asBinder().unlinkToDeath(old, 0);
+                        }
+                    }
+                });
+        }
+
+        @Override
+        public void addSubscriptionDeprecated(String id, IMediaBrowserServiceCallbacks callbacks) {
+            // do-nothing
+        }
+
+        @Override
+        public void addSubscription(final String id, final IBinder token, final Bundle options,
+                final IMediaBrowserServiceCallbacks callbacks) {
+            mHandler.post(new Runnable() {
+                    @Override
+                    public void run() {
+                        final IBinder b = callbacks.asBinder();
+
+                        // Get the record for the connection
+                        final ConnectionRecord connection = mConnections.get(b);
+                        if (connection == null) {
+                            Log.w(TAG, "addSubscription for callback that isn't registered id="
+                                + id);
+                            return;
+                        }
+
+                        MediaBrowserService.this.addSubscription(id, connection, token, options);
+                    }
+                });
+        }
+
+        @Override
+        public void removeSubscriptionDeprecated(String id, IMediaBrowserServiceCallbacks callbacks) {
+            // do-nothing
+        }
+
+        @Override
+        public void removeSubscription(final String id, final IBinder token,
+                final IMediaBrowserServiceCallbacks callbacks) {
+            mHandler.post(new Runnable() {
+                @Override
+                public void run() {
+                    final IBinder b = callbacks.asBinder();
+
+                    ConnectionRecord connection = mConnections.get(b);
+                    if (connection == null) {
+                        Log.w(TAG, "removeSubscription for callback that isn't registered id="
+                                + id);
+                        return;
+                    }
+                    if (!MediaBrowserService.this.removeSubscription(id, connection, token)) {
+                        Log.w(TAG, "removeSubscription called for " + id
+                                + " which is not subscribed");
+                    }
+                }
+            });
+        }
+
+        @Override
+        public void getMediaItem(final String mediaId, final ResultReceiver receiver,
+                final IMediaBrowserServiceCallbacks callbacks) {
+            mHandler.post(new Runnable() {
+                @Override
+                public void run() {
+                    final IBinder b = callbacks.asBinder();
+                    ConnectionRecord connection = mConnections.get(b);
+                    if (connection == null) {
+                        Log.w(TAG, "getMediaItem for callback that isn't registered id=" + mediaId);
+                        return;
+                    }
+                    performLoadItem(mediaId, connection, receiver);
+                }
+            });
+        }
+    }
+
+    @Override
+    public void onCreate() {
+        super.onCreate();
+        mBinder = new ServiceBinder();
+    }
+
+    @Override
+    public IBinder onBind(Intent intent) {
+        if (SERVICE_INTERFACE.equals(intent.getAction())) {
+            return mBinder;
+        }
+        return null;
+    }
+
+    @Override
+    public void dump(FileDescriptor fd, PrintWriter writer, String[] args) {
+    }
+
+    /**
+     * Called to get the root information for browsing by a particular client.
+     * <p>
+     * The implementation should verify that the client package has permission
+     * to access browse media information before returning the root id; it
+     * should return null if the client is not allowed to access this
+     * information.
+     * </p>
+     *
+     * @param clientPackageName The package name of the application which is
+     *            requesting access to browse media.
+     * @param clientUid The uid of the application which is requesting access to
+     *            browse media.
+     * @param rootHints An optional bundle of service-specific arguments to send
+     *            to the media browser service when connecting and retrieving the
+     *            root id for browsing, or null if none. The contents of this
+     *            bundle may affect the information returned when browsing.
+     * @return The {@link BrowserRoot} for accessing this app's content or null.
+     * @see BrowserRoot#EXTRA_RECENT
+     * @see BrowserRoot#EXTRA_OFFLINE
+     * @see BrowserRoot#EXTRA_SUGGESTED
+     */
+    public abstract @Nullable BrowserRoot onGetRoot(@NonNull String clientPackageName,
+            int clientUid, @Nullable Bundle rootHints);
+
+    /**
+     * Called to get information about the children of a media item.
+     * <p>
+     * Implementations must call {@link Result#sendResult result.sendResult}
+     * with the list of children. If loading the children will be an expensive
+     * operation that should be performed on another thread,
+     * {@link Result#detach result.detach} may be called before returning from
+     * this function, and then {@link Result#sendResult result.sendResult}
+     * called when the loading is complete.
+     * </p><p>
+     * In case the media item does not have any children, call {@link Result#sendResult}
+     * with an empty list. When the given {@code parentId} is invalid, implementations must
+     * call {@link Result#sendResult result.sendResult} with {@code null}, which will invoke
+     * {@link MediaBrowser.SubscriptionCallback#onError}.
+     * </p>
+     *
+     * @param parentId The id of the parent media item whose children are to be
+     *            queried.
+     * @param result The Result to send the list of children to.
+     */
+    public abstract void onLoadChildren(@NonNull String parentId,
+            @NonNull Result<List<MediaBrowser.MediaItem>> result);
+
+    /**
+     * Called to get information about the children of a media item.
+     * <p>
+     * Implementations must call {@link Result#sendResult result.sendResult}
+     * with the list of children. If loading the children will be an expensive
+     * operation that should be performed on another thread,
+     * {@link Result#detach result.detach} may be called before returning from
+     * this function, and then {@link Result#sendResult result.sendResult}
+     * called when the loading is complete.
+     * </p><p>
+     * In case the media item does not have any children, call {@link Result#sendResult}
+     * with an empty list. When the given {@code parentId} is invalid, implementations must
+     * call {@link Result#sendResult result.sendResult} with {@code null}, which will invoke
+     * {@link MediaBrowser.SubscriptionCallback#onError}.
+     * </p>
+     *
+     * @param parentId The id of the parent media item whose children are to be
+     *            queried.
+     * @param result The Result to send the list of children to.
+     * @param options The bundle of service-specific arguments sent from the media
+     *            browser. The information returned through the result should be
+     *            affected by the contents of this bundle.
+     */
+    public void onLoadChildren(@NonNull String parentId,
+            @NonNull Result<List<MediaBrowser.MediaItem>> result, @NonNull Bundle options) {
+        // To support backward compatibility, when the implementation of MediaBrowserService doesn't
+        // override onLoadChildren() with options, onLoadChildren() without options will be used
+        // instead, and the options will be applied in the implementation of result.onResultSent().
+        result.setFlags(RESULT_FLAG_OPTION_NOT_HANDLED);
+        onLoadChildren(parentId, result);
+    }
+
+    /**
+     * Called to get information about a specific media item.
+     * <p>
+     * Implementations must call {@link Result#sendResult result.sendResult}. If
+     * loading the item will be an expensive operation {@link Result#detach
+     * result.detach} may be called before returning from this function, and
+     * then {@link Result#sendResult result.sendResult} called when the item has
+     * been loaded.
+     * </p><p>
+     * When the given {@code itemId} is invalid, implementations must call
+     * {@link Result#sendResult result.sendResult} with {@code null}.
+     * </p><p>
+     * The default implementation will invoke {@link MediaBrowser.ItemCallback#onError}.
+     * </p>
+     *
+     * @param itemId The id for the specific
+     *            {@link android.media.browse.MediaBrowser.MediaItem}.
+     * @param result The Result to send the item to.
+     */
+    public void onLoadItem(String itemId, Result<MediaBrowser.MediaItem> result) {
+        result.setFlags(RESULT_FLAG_ON_LOAD_ITEM_NOT_IMPLEMENTED);
+        result.sendResult(null);
+    }
+
+    /**
+     * Call to set the media session.
+     * <p>
+     * This should be called as soon as possible during the service's startup.
+     * It may only be called once.
+     *
+     * @param token The token for the service's {@link MediaSession}.
+     */
+    public void setSessionToken(final MediaSession.Token token) {
+        if (token == null) {
+            throw new IllegalArgumentException("Session token may not be null.");
+        }
+        if (mSession != null) {
+            throw new IllegalStateException("The session token has already been set.");
+        }
+        mSession = token;
+        mHandler.post(new Runnable() {
+            @Override
+            public void run() {
+                Iterator<ConnectionRecord> iter = mConnections.values().iterator();
+                while (iter.hasNext()){
+                    ConnectionRecord connection = iter.next();
+                    try {
+                        connection.callbacks.onConnect(connection.root.getRootId(), token,
+                                connection.root.getExtras());
+                    } catch (RemoteException e) {
+                        Log.w(TAG, "Connection for " + connection.pkg + " is no longer valid.");
+                        iter.remove();
+                    }
+                }
+            }
+        });
+    }
+
+    /**
+     * Gets the session token, or null if it has not yet been created
+     * or if it has been destroyed.
+     */
+    public @Nullable MediaSession.Token getSessionToken() {
+        return mSession;
+    }
+
+    /**
+     * Gets the root hints sent from the currently connected {@link MediaBrowser}.
+     * The root hints are service-specific arguments included in an optional bundle sent to the
+     * media browser service when connecting and retrieving the root id for browsing, or null if
+     * none. The contents of this bundle may affect the information returned when browsing.
+     *
+     * @throws IllegalStateException If this method is called outside of {@link #onGetRoot} or
+     *             {@link #onLoadChildren} or {@link #onLoadItem}.
+     * @see MediaBrowserService.BrowserRoot#EXTRA_RECENT
+     * @see MediaBrowserService.BrowserRoot#EXTRA_OFFLINE
+     * @see MediaBrowserService.BrowserRoot#EXTRA_SUGGESTED
+     */
+    public final Bundle getBrowserRootHints() {
+        if (mCurConnection == null) {
+            throw new IllegalStateException("This should be called inside of onGetRoot or"
+                    + " onLoadChildren or onLoadItem methods");
+        }
+        return mCurConnection.rootHints == null ? null : new Bundle(mCurConnection.rootHints);
+    }
+
+    /**
+     * Gets the browser information who sent the current request.
+     *
+     * @throws IllegalStateException If this method is called outside of {@link #onGetRoot} or
+     *             {@link #onLoadChildren} or {@link #onLoadItem}.
+     * @see MediaSessionManager#isTrustedForMediaControl(RemoteUserInfo)
+     */
+    public final RemoteUserInfo getCurrentBrowserInfo() {
+        if (mCurConnection == null) {
+            throw new IllegalStateException("This should be called inside of onGetRoot or"
+                    + " onLoadChildren or onLoadItem methods");
+        }
+        //TODO(b/119752205): Resolve hidden API usage. 4-param constructor of RemoteUserInfo
+        /*
+        return new RemoteUserInfo(mCurConnection.pkg, mCurConnection.pid, mCurConnection.uid,
+                mCurConnection.callbacks.asBinder());
+        */
+        return new RemoteUserInfo(mCurConnection.pkg, mCurConnection.pid, mCurConnection.uid);
+    }
+
+    /**
+     * Notifies all connected media browsers that the children of
+     * the specified parent id have changed in some way.
+     * This will cause browsers to fetch subscribed content again.
+     *
+     * @param parentId The id of the parent media item whose
+     * children changed.
+     */
+    public void notifyChildrenChanged(@NonNull String parentId) {
+        notifyChildrenChangedInternal(parentId, null);
+    }
+
+    /**
+     * Notifies all connected media browsers that the children of
+     * the specified parent id have changed in some way.
+     * This will cause browsers to fetch subscribed content again.
+     *
+     * @param parentId The id of the parent media item whose
+     *            children changed.
+     * @param options The bundle of service-specific arguments to send
+     *            to the media browser. The contents of this bundle may
+     *            contain the information about the change.
+     */
+    public void notifyChildrenChanged(@NonNull String parentId, @NonNull Bundle options) {
+        if (options == null) {
+            throw new IllegalArgumentException("options cannot be null in notifyChildrenChanged");
+        }
+        notifyChildrenChangedInternal(parentId, options);
+    }
+
+    private void notifyChildrenChangedInternal(final String parentId, final Bundle options) {
+        if (parentId == null) {
+            throw new IllegalArgumentException("parentId cannot be null in notifyChildrenChanged");
+        }
+        mHandler.post(new Runnable() {
+            @Override
+            public void run() {
+                for (IBinder binder : mConnections.keySet()) {
+                    ConnectionRecord connection = mConnections.get(binder);
+                    List<Pair<IBinder, Bundle>> callbackList =
+                            connection.subscriptions.get(parentId);
+                    if (callbackList != null) {
+                        for (Pair<IBinder, Bundle> callback : callbackList) {
+                            if (MediaBrowserUtils.hasDuplicatedItems(options, callback.second)) {
+                                performLoadChildren(parentId, connection, callback.second);
+                            }
+                        }
+                    }
+                }
+            }
+        });
+    }
+
+    /**
+     * Return whether the given package is one of the ones that is owned by the uid.
+     */
+    private boolean isValidPackage(String pkg, int uid) {
+        if (pkg == null) {
+            return false;
+        }
+        final PackageManager pm = getPackageManager();
+        final String[] packages = pm.getPackagesForUid(uid);
+        final int N = packages.length;
+        for (int i=0; i<N; i++) {
+            if (packages[i].equals(pkg)) {
+                return true;
+            }
+        }
+        return false;
+    }
+
+    /**
+     * Save the subscription and if it is a new subscription send the results.
+     */
+    private void addSubscription(String id, ConnectionRecord connection, IBinder token,
+            Bundle options) {
+        // Save the subscription
+        List<Pair<IBinder, Bundle>> callbackList = connection.subscriptions.get(id);
+        if (callbackList == null) {
+            callbackList = new ArrayList<>();
+        }
+        for (Pair<IBinder, Bundle> callback : callbackList) {
+            if (token == callback.first
+                    && MediaBrowserUtils.areSameOptions(options, callback.second)) {
+                return;
+            }
+        }
+        callbackList.add(new Pair<>(token, options));
+        connection.subscriptions.put(id, callbackList);
+        // send the results
+        performLoadChildren(id, connection, options);
+    }
+
+    /**
+     * Remove the subscription.
+     */
+    private boolean removeSubscription(String id, ConnectionRecord connection, IBinder token) {
+        if (token == null) {
+            return connection.subscriptions.remove(id) != null;
+        }
+        boolean removed = false;
+        List<Pair<IBinder, Bundle>> callbackList = connection.subscriptions.get(id);
+        if (callbackList != null) {
+            Iterator<Pair<IBinder, Bundle>> iter = callbackList.iterator();
+            while (iter.hasNext()){
+                if (token == iter.next().first) {
+                    removed = true;
+                    iter.remove();
+                }
+            }
+            if (callbackList.size() == 0) {
+                connection.subscriptions.remove(id);
+            }
+        }
+        return removed;
+    }
+
+    /**
+     * Call onLoadChildren and then send the results back to the connection.
+     * <p>
+     * Callers must make sure that this connection is still connected.
+     */
+    private void performLoadChildren(final String parentId, final ConnectionRecord connection,
+            final Bundle options) {
+        final Result<List<MediaBrowser.MediaItem>> result
+                = new Result<List<MediaBrowser.MediaItem>>(parentId) {
+            @Override
+            void onResultSent(List<MediaBrowser.MediaItem> list, @ResultFlags int flag) {
+                if (mConnections.get(connection.callbacks.asBinder()) != connection) {
+                    if (DBG) {
+                        Log.d(TAG, "Not sending onLoadChildren result for connection that has"
+                                + " been disconnected. pkg=" + connection.pkg + " id=" + parentId);
+                    }
+                    return;
+                }
+
+                List<MediaBrowser.MediaItem> filteredList =
+                        (flag & RESULT_FLAG_OPTION_NOT_HANDLED) != 0
+                        ? applyOptions(list, options) : list;
+                //TODO:(b/119750807) Resolve hidden API usage ParceledListSlice.
+                /*
+                final ParceledListSlice<MediaBrowser.MediaItem> pls =
+                        filteredList == null ? null : new ParceledListSlice<>(filteredList);
+                try {
+                    connection.callbacks.onLoadChildrenWithOptions(parentId, pls, options);
+                } catch (RemoteException ex) {
+                    // The other side is in the process of crashing.
+                    Log.w(TAG, "Calling onLoadChildren() failed for id=" + parentId
+                            + " package=" + connection.pkg);
+                }
+                */
+            }
+        };
+
+        mCurConnection = connection;
+        if (options == null) {
+            onLoadChildren(parentId, result);
+        } else {
+            onLoadChildren(parentId, result, options);
+        }
+        mCurConnection = null;
+
+        if (!result.isDone()) {
+            throw new IllegalStateException("onLoadChildren must call detach() or sendResult()"
+                    + " before returning for package=" + connection.pkg + " id=" + parentId);
+        }
+    }
+
+    private List<MediaBrowser.MediaItem> applyOptions(List<MediaBrowser.MediaItem> list,
+            final Bundle options) {
+        if (list == null) {
+            return null;
+        }
+        int page = options.getInt(MediaBrowser.EXTRA_PAGE, -1);
+        int pageSize = options.getInt(MediaBrowser.EXTRA_PAGE_SIZE, -1);
+        if (page == -1 && pageSize == -1) {
+            return list;
+        }
+        int fromIndex = pageSize * page;
+        int toIndex = fromIndex + pageSize;
+        if (page < 0 || pageSize < 1 || fromIndex >= list.size()) {
+            return Collections.EMPTY_LIST;
+        }
+        if (toIndex > list.size()) {
+            toIndex = list.size();
+        }
+        return list.subList(fromIndex, toIndex);
+    }
+
+    private void performLoadItem(String itemId, final ConnectionRecord connection,
+            final ResultReceiver receiver) {
+        final Result<MediaBrowser.MediaItem> result =
+                new Result<MediaBrowser.MediaItem>(itemId) {
+            @Override
+            void onResultSent(MediaBrowser.MediaItem item, @ResultFlags int flag) {
+                if (mConnections.get(connection.callbacks.asBinder()) != connection) {
+                    if (DBG) {
+                        Log.d(TAG, "Not sending onLoadItem result for connection that has"
+                                + " been disconnected. pkg=" + connection.pkg + " id=" + itemId);
+                    }
+                    return;
+                }
+                if ((flag & RESULT_FLAG_ON_LOAD_ITEM_NOT_IMPLEMENTED) != 0) {
+                    receiver.send(RESULT_ERROR, null);
+                    return;
+                }
+                Bundle bundle = new Bundle();
+                bundle.putParcelable(KEY_MEDIA_ITEM, item);
+                receiver.send(RESULT_OK, bundle);
+            }
+        };
+
+        mCurConnection = connection;
+        onLoadItem(itemId, result);
+        mCurConnection = null;
+
+        if (!result.isDone()) {
+            throw new IllegalStateException("onLoadItem must call detach() or sendResult()"
+                    + " before returning for id=" + itemId);
+        }
+    }
+
+    /**
+     * Contains information that the browser service needs to send to the client
+     * when first connected.
+     */
+    public static final class BrowserRoot {
+        /**
+         * The lookup key for a boolean that indicates whether the browser service should return a
+         * browser root for recently played media items.
+         *
+         * <p>When creating a media browser for a given media browser service, this key can be
+         * supplied as a root hint for retrieving media items that are recently played.
+         * If the media browser service can provide such media items, the implementation must return
+         * the key in the root hint when {@link #onGetRoot(String, int, Bundle)} is called back.
+         *
+         * <p>The root hint may contain multiple keys.
+         *
+         * @see #EXTRA_OFFLINE
+         * @see #EXTRA_SUGGESTED
+         */
+        public static final String EXTRA_RECENT = "android.service.media.extra.RECENT";
+
+        /**
+         * The lookup key for a boolean that indicates whether the browser service should return a
+         * browser root for offline media items.
+         *
+         * <p>When creating a media browser for a given media browser service, this key can be
+         * supplied as a root hint for retrieving media items that are can be played without an
+         * internet connection.
+         * If the media browser service can provide such media items, the implementation must return
+         * the key in the root hint when {@link #onGetRoot(String, int, Bundle)} is called back.
+         *
+         * <p>The root hint may contain multiple keys.
+         *
+         * @see #EXTRA_RECENT
+         * @see #EXTRA_SUGGESTED
+         */
+        public static final String EXTRA_OFFLINE = "android.service.media.extra.OFFLINE";
+
+        /**
+         * The lookup key for a boolean that indicates whether the browser service should return a
+         * browser root for suggested media items.
+         *
+         * <p>When creating a media browser for a given media browser service, this key can be
+         * supplied as a root hint for retrieving the media items suggested by the media browser
+         * service. The list of media items passed in {@link android.media.browse.MediaBrowser.SubscriptionCallback#onChildrenLoaded(String, List)}
+         * is considered ordered by relevance, first being the top suggestion.
+         * If the media browser service can provide such media items, the implementation must return
+         * the key in the root hint when {@link #onGetRoot(String, int, Bundle)} is called back.
+         *
+         * <p>The root hint may contain multiple keys.
+         *
+         * @see #EXTRA_RECENT
+         * @see #EXTRA_OFFLINE
+         */
+        public static final String EXTRA_SUGGESTED = "android.service.media.extra.SUGGESTED";
+
+        final private String mRootId;
+        final private Bundle mExtras;
+
+        /**
+         * Constructs a browser root.
+         * @param rootId The root id for browsing.
+         * @param extras Any extras about the browser service.
+         */
+        public BrowserRoot(@NonNull String rootId, @Nullable Bundle extras) {
+            if (rootId == null) {
+                throw new IllegalArgumentException("The root id in BrowserRoot cannot be null. " +
+                        "Use null for BrowserRoot instead.");
+            }
+            mRootId = rootId;
+            mExtras = extras;
+        }
+
+        /**
+         * Gets the root id for browsing.
+         */
+        public String getRootId() {
+            return mRootId;
+        }
+
+        /**
+         * Gets any extras about the browser service.
+         */
+        public Bundle getExtras() {
+            return mExtras;
+        }
+    }
+}