Collapse common package (2/2)

Ran optimize imports on the project as well to re-order everything
which would have changed because of removing common.

Test: Built GoogleContacts, GoogleContactsTests, Contacts,
ContactsTests and ran unit tests.

Bug: 33252370
Change-Id: I881f0ba8b8fef002b6eeefa9a16b34f15b2fd2a9
diff --git a/src/com/android/contacts/ContactPhotoManager.java b/src/com/android/contacts/ContactPhotoManager.java
new file mode 100644
index 0000000..b43af19
--- /dev/null
+++ b/src/com/android/contacts/ContactPhotoManager.java
@@ -0,0 +1,1743 @@
+/*
+ * Copyright (C) 2010 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 com.android.contacts;
+
+import android.app.ActivityManager;
+import android.content.ComponentCallbacks2;
+import android.content.ContentResolver;
+import android.content.ContentUris;
+import android.content.Context;
+import android.content.res.Configuration;
+import android.content.res.Resources;
+import android.database.Cursor;
+import android.graphics.Bitmap;
+import android.graphics.Canvas;
+import android.graphics.Color;
+import android.graphics.Paint;
+import android.graphics.Paint.Style;
+import android.graphics.drawable.BitmapDrawable;
+import android.graphics.drawable.ColorDrawable;
+import android.graphics.drawable.Drawable;
+import android.graphics.drawable.TransitionDrawable;
+import android.media.ThumbnailUtils;
+import android.net.TrafficStats;
+import android.net.Uri;
+import android.net.Uri.Builder;
+import android.os.Handler;
+import android.os.Handler.Callback;
+import android.os.HandlerThread;
+import android.os.Message;
+import android.provider.ContactsContract;
+import android.provider.ContactsContract.Contacts;
+import android.provider.ContactsContract.Contacts.Photo;
+import android.provider.ContactsContract.Data;
+import android.provider.ContactsContract.Directory;
+import android.support.v4.graphics.drawable.RoundedBitmapDrawable;
+import android.support.v4.graphics.drawable.RoundedBitmapDrawableFactory;
+import android.text.TextUtils;
+import android.util.Log;
+import android.util.LruCache;
+import android.view.View;
+import android.view.ViewGroup;
+import android.widget.ImageView;
+
+import com.android.contacts.lettertiles.LetterTileDrawable;
+import com.android.contacts.util.BitmapUtil;
+import com.android.contacts.util.PermissionsUtil;
+import com.android.contacts.util.TrafficStatsTags;
+import com.android.contacts.util.UriUtils;
+import com.android.contactsbind.util.UserAgentGenerator;
+
+import com.google.common.annotations.VisibleForTesting;
+import com.google.common.collect.Lists;
+import com.google.common.collect.Sets;
+
+import java.io.ByteArrayOutputStream;
+import java.io.IOException;
+import java.io.InputStream;
+import java.lang.ref.Reference;
+import java.lang.ref.SoftReference;
+import java.net.HttpURLConnection;
+import java.net.URL;
+import java.util.Iterator;
+import java.util.List;
+import java.util.Map.Entry;
+import java.util.Set;
+import java.util.concurrent.ConcurrentHashMap;
+import java.util.concurrent.atomic.AtomicInteger;
+
+/**
+ * Asynchronously loads contact photos and maintains a cache of photos.
+ */
+public abstract class ContactPhotoManager implements ComponentCallbacks2 {
+    static final String TAG = "ContactPhotoManager";
+    static final boolean DEBUG = false; // Don't submit with true
+    static final boolean DEBUG_SIZES = false; // Don't submit with true
+
+    /** Contact type constants used for default letter images */
+    public static final int TYPE_PERSON = LetterTileDrawable.TYPE_PERSON;
+    public static final int TYPE_BUSINESS = LetterTileDrawable.TYPE_BUSINESS;
+    public static final int TYPE_VOICEMAIL = LetterTileDrawable.TYPE_VOICEMAIL;
+    public static final int TYPE_DEFAULT = LetterTileDrawable.TYPE_DEFAULT;
+
+    /** Scale and offset default constants used for default letter images */
+    public static final float SCALE_DEFAULT = 1.0f;
+    public static final float OFFSET_DEFAULT = 0.0f;
+
+    public static final boolean IS_CIRCULAR_DEFAULT = false;
+
+    /** Uri-related constants used for default letter images */
+    private static final String DISPLAY_NAME_PARAM_KEY = "display_name";
+    private static final String IDENTIFIER_PARAM_KEY = "identifier";
+    private static final String CONTACT_TYPE_PARAM_KEY = "contact_type";
+    private static final String SCALE_PARAM_KEY = "scale";
+    private static final String OFFSET_PARAM_KEY = "offset";
+    private static final String IS_CIRCULAR_PARAM_KEY = "is_circular";
+    private static final String DEFAULT_IMAGE_URI_SCHEME = "defaultimage";
+    private static final Uri DEFAULT_IMAGE_URI = Uri.parse(DEFAULT_IMAGE_URI_SCHEME + "://");
+
+    // Static field used to cache the default letter avatar drawable that is created
+    // using a null {@link DefaultImageRequest}
+    private static Drawable sDefaultLetterAvatar = null;
+
+    private static ContactPhotoManager sInstance;
+
+    /**
+     * Given a {@link DefaultImageRequest}, returns a {@link Drawable}, that when drawn, will
+     * draw a letter tile avatar based on the request parameters defined in the
+     * {@link DefaultImageRequest}.
+     */
+    public static Drawable getDefaultAvatarDrawableForContact(Resources resources, boolean hires,
+            DefaultImageRequest defaultImageRequest) {
+        if (defaultImageRequest == null) {
+            if (sDefaultLetterAvatar == null) {
+                // Cache and return the letter tile drawable that is created by a null request,
+                // so that it doesn't have to be recreated every time it is requested again.
+                sDefaultLetterAvatar = LetterTileDefaultImageProvider.getDefaultImageForContact(
+                        resources, null);
+            }
+            return sDefaultLetterAvatar;
+        }
+        return LetterTileDefaultImageProvider.getDefaultImageForContact(resources,
+                defaultImageRequest);
+    }
+
+    /**
+     * Given a {@link DefaultImageRequest}, returns an Uri that can be used to request a
+     * letter tile avatar when passed to the {@link ContactPhotoManager}. The internal
+     * implementation of this uri is not guaranteed to remain the same across application
+     * versions, so the actual uri should never be persisted in long-term storage and reused.
+     *
+     * @param request A {@link DefaultImageRequest} object with the fields configured
+     * to return a
+     * @return A Uri that when later passed to the {@link ContactPhotoManager} via
+     * {@link #loadPhoto(ImageView, Uri, int, boolean, DefaultImageRequest)}, can be
+     * used to request a default contact image, drawn as a letter tile using the
+     * parameters as configured in the provided {@link DefaultImageRequest}
+     */
+    public static Uri getDefaultAvatarUriForContact(DefaultImageRequest request) {
+        final Builder builder = DEFAULT_IMAGE_URI.buildUpon();
+        if (request != null) {
+            if (!TextUtils.isEmpty(request.displayName)) {
+                builder.appendQueryParameter(DISPLAY_NAME_PARAM_KEY, request.displayName);
+            }
+            if (!TextUtils.isEmpty(request.identifier)) {
+                builder.appendQueryParameter(IDENTIFIER_PARAM_KEY, request.identifier);
+            }
+            if (request.contactType != TYPE_DEFAULT) {
+                builder.appendQueryParameter(CONTACT_TYPE_PARAM_KEY,
+                        String.valueOf(request.contactType));
+            }
+            if (request.scale != SCALE_DEFAULT) {
+                builder.appendQueryParameter(SCALE_PARAM_KEY, String.valueOf(request.scale));
+            }
+            if (request.offset != OFFSET_DEFAULT) {
+                builder.appendQueryParameter(OFFSET_PARAM_KEY, String.valueOf(request.offset));
+            }
+            if (request.isCircular != IS_CIRCULAR_DEFAULT) {
+                builder.appendQueryParameter(IS_CIRCULAR_PARAM_KEY,
+                        String.valueOf(request.isCircular));
+            }
+
+        }
+        return builder.build();
+    }
+
+    /**
+     * Adds a business contact type encoded fragment to the URL.  Used to ensure photo URLS
+     * from Nearby Places can be identified as business photo URLs rather than URLs for personal
+     * contact photos.
+     *
+     * @param photoUrl The photo URL to modify.
+     * @return URL with the contact type parameter added and set to TYPE_BUSINESS.
+     */
+    public static String appendBusinessContactType(String photoUrl) {
+        Uri uri = Uri.parse(photoUrl);
+        Builder builder = uri.buildUpon();
+        builder.encodedFragment(String.valueOf(TYPE_BUSINESS));
+        return builder.build().toString();
+    }
+
+    /**
+     * Removes the contact type information stored in the photo URI encoded fragment.
+     *
+     * @param photoUri The photo URI to remove the contact type from.
+     * @return The photo URI with contact type removed.
+     */
+    public static Uri removeContactType(Uri photoUri) {
+        String encodedFragment = photoUri.getEncodedFragment();
+        if (!TextUtils.isEmpty(encodedFragment)) {
+            Builder builder = photoUri.buildUpon();
+            builder.encodedFragment(null);
+            return builder.build();
+        }
+        return photoUri;
+    }
+
+    /**
+     * Inspects a photo URI to determine if the photo URI represents a business.
+     *
+     * @param photoUri The URI to inspect.
+     * @return Whether the URI represents a business photo or not.
+     */
+    public static boolean isBusinessContactUri(Uri photoUri) {
+        if (photoUri == null) {
+            return false;
+        }
+
+        String encodedFragment = photoUri.getEncodedFragment();
+        return !TextUtils.isEmpty(encodedFragment)
+                && encodedFragment.equals(String.valueOf(TYPE_BUSINESS));
+    }
+
+    protected static DefaultImageRequest getDefaultImageRequestFromUri(Uri uri) {
+        final DefaultImageRequest request = new DefaultImageRequest(
+                uri.getQueryParameter(DISPLAY_NAME_PARAM_KEY),
+                uri.getQueryParameter(IDENTIFIER_PARAM_KEY), false);
+        try {
+            String contactType = uri.getQueryParameter(CONTACT_TYPE_PARAM_KEY);
+            if (!TextUtils.isEmpty(contactType)) {
+                request.contactType = Integer.valueOf(contactType);
+            }
+
+            String scale = uri.getQueryParameter(SCALE_PARAM_KEY);
+            if (!TextUtils.isEmpty(scale)) {
+                request.scale = Float.valueOf(scale);
+            }
+
+            String offset = uri.getQueryParameter(OFFSET_PARAM_KEY);
+            if (!TextUtils.isEmpty(offset)) {
+                request.offset = Float.valueOf(offset);
+            }
+
+            String isCircular = uri.getQueryParameter(IS_CIRCULAR_PARAM_KEY);
+            if (!TextUtils.isEmpty(isCircular)) {
+                request.isCircular = Boolean.valueOf(isCircular);
+            }
+        } catch (NumberFormatException e) {
+            Log.w(TAG, "Invalid DefaultImageRequest image parameters provided, ignoring and using "
+                    + "defaults.");
+        }
+
+        return request;
+    }
+
+    protected boolean isDefaultImageUri(Uri uri) {
+        return DEFAULT_IMAGE_URI_SCHEME.equals(uri.getScheme());
+    }
+
+    /**
+     * Contains fields used to contain contact details and other user-defined settings that might
+     * be used by the ContactPhotoManager to generate a default contact image. This contact image
+     * takes the form of a letter or bitmap drawn on top of a colored tile.
+     */
+    public static class DefaultImageRequest {
+        /**
+         * The contact's display name. The display name is used to
+         */
+        public String displayName;
+
+        /**
+         * A unique and deterministic string that can be used to identify this contact. This is
+         * usually the contact's lookup key, but other contact details can be used as well,
+         * especially for non-local or temporary contacts that might not have a lookup key. This
+         * is used to determine the color of the tile.
+         */
+        public String identifier;
+
+        /**
+         * The type of this contact. This contact type may be used to decide the kind of
+         * image to use in the case where a unique letter cannot be generated from the contact's
+         * display name and identifier. See:
+         * {@link #TYPE_PERSON}
+         * {@link #TYPE_BUSINESS}
+         * {@link #TYPE_PERSON}
+         * {@link #TYPE_DEFAULT}
+         */
+        public int contactType = TYPE_DEFAULT;
+
+        /**
+         * The amount to scale the letter or bitmap to, as a ratio of its default size (from a
+         * range of 0.0f to 2.0f). The default value is 1.0f.
+         */
+        public float scale = SCALE_DEFAULT;
+
+        /**
+         * The amount to vertically offset the letter or image to within the tile.
+         * The provided offset must be within the range of -0.5f to 0.5f.
+         * If set to -0.5f, the letter will be shifted upwards by 0.5 times the height of the canvas
+         * it is being drawn on, which means it will be drawn with the center of the letter starting
+         * at the top edge of the canvas.
+         * If set to 0.5f, the letter will be shifted downwards by 0.5 times the height of the
+         * canvas it is being drawn on, which means it will be drawn with the center of the letter
+         * starting at the bottom edge of the canvas.
+         * The default is 0.0f, which means the letter is drawn in the exact vertical center of
+         * the tile.
+         */
+        public float offset = OFFSET_DEFAULT;
+
+        /**
+         * Whether or not to draw the default image as a circle, instead of as a square/rectangle.
+         */
+        public boolean isCircular = false;
+
+        /**
+         * Used to indicate that a drawable that represents a contact without any contact details
+         * should be returned.
+         */
+        public static DefaultImageRequest EMPTY_DEFAULT_IMAGE_REQUEST = new DefaultImageRequest();
+
+        /**
+         * Used to indicate that a drawable that represents a business without a business photo
+         * should be returned.
+         */
+        public static DefaultImageRequest EMPTY_DEFAULT_BUSINESS_IMAGE_REQUEST =
+                new DefaultImageRequest(null, null, TYPE_BUSINESS, false);
+
+        /**
+         * Used to indicate that a circular drawable that represents a contact without any contact
+         * details should be returned.
+         */
+        public static DefaultImageRequest EMPTY_CIRCULAR_DEFAULT_IMAGE_REQUEST =
+                new DefaultImageRequest(null, null, true);
+
+        /**
+         * Used to indicate that a circular drawable that represents a business without a business
+         * photo should be returned.
+         */
+        public static DefaultImageRequest EMPTY_CIRCULAR_BUSINESS_IMAGE_REQUEST =
+                new DefaultImageRequest(null, null, TYPE_BUSINESS, true);
+
+        public DefaultImageRequest() {
+        }
+
+        public DefaultImageRequest(String displayName, String identifier, boolean isCircular) {
+            this(displayName, identifier, TYPE_DEFAULT, SCALE_DEFAULT, OFFSET_DEFAULT, isCircular);
+        }
+
+        public DefaultImageRequest(String displayName, String identifier, int contactType,
+                boolean isCircular) {
+            this(displayName, identifier, contactType, SCALE_DEFAULT, OFFSET_DEFAULT, isCircular);
+        }
+
+        public DefaultImageRequest(String displayName, String identifier, int contactType,
+                float scale, float offset, boolean isCircular) {
+            this.displayName = displayName;
+            this.identifier = identifier;
+            this.contactType = contactType;
+            this.scale = scale;
+            this.offset = offset;
+            this.isCircular = isCircular;
+        }
+    }
+
+    public static abstract class DefaultImageProvider {
+        /**
+         * Applies the default avatar to the ImageView. Extent is an indicator for the size (width
+         * or height). If darkTheme is set, the avatar is one that looks better on dark background
+         *
+         * @param defaultImageRequest {@link DefaultImageRequest} object that specifies how a
+         * default letter tile avatar should be drawn.
+         */
+        public abstract void applyDefaultImage(ImageView view, int extent, boolean darkTheme,
+                DefaultImageRequest defaultImageRequest);
+    }
+
+    /**
+     * A default image provider that applies a letter tile consisting of a colored background
+     * and a letter in the foreground as the default image for a contact. The color of the
+     * background and the type of letter is decided based on the contact's details.
+     */
+    private static class LetterTileDefaultImageProvider extends DefaultImageProvider {
+        @Override
+        public void applyDefaultImage(ImageView view, int extent, boolean darkTheme,
+                DefaultImageRequest defaultImageRequest) {
+            final Drawable drawable = getDefaultImageForContact(view.getResources(),
+                    defaultImageRequest);
+            view.setImageDrawable(drawable);
+        }
+
+        public static Drawable getDefaultImageForContact(Resources resources,
+                DefaultImageRequest defaultImageRequest) {
+            final LetterTileDrawable drawable = new LetterTileDrawable(resources);
+            if (defaultImageRequest != null) {
+                // If the contact identifier is null or empty, fallback to the
+                // displayName. In that case, use {@code null} for the contact's
+                // display name so that a default bitmap will be used instead of a
+                // letter
+                if (TextUtils.isEmpty(defaultImageRequest.identifier)) {
+                    drawable.setLetterAndColorFromContactDetails(null,
+                            defaultImageRequest.displayName);
+                } else {
+                    drawable.setLetterAndColorFromContactDetails(defaultImageRequest.displayName,
+                            defaultImageRequest.identifier);
+                }
+                drawable.setContactType(defaultImageRequest.contactType);
+                drawable.setScale(defaultImageRequest.scale);
+                drawable.setOffset(defaultImageRequest.offset);
+                drawable.setIsCircular(defaultImageRequest.isCircular);
+            }
+            return drawable;
+        }
+    }
+
+    private static class BlankDefaultImageProvider extends DefaultImageProvider {
+        private static Drawable sDrawable;
+
+        @Override
+        public void applyDefaultImage(ImageView view, int extent, boolean darkTheme,
+                DefaultImageRequest defaultImageRequest) {
+            if (sDrawable == null) {
+                Context context = view.getContext();
+                sDrawable = new ColorDrawable(context.getResources().getColor(
+                        R.color.image_placeholder));
+            }
+            view.setImageDrawable(sDrawable);
+        }
+    }
+
+    public static DefaultImageProvider DEFAULT_AVATAR = new LetterTileDefaultImageProvider();
+
+    public static final DefaultImageProvider DEFAULT_BLANK = new BlankDefaultImageProvider();
+
+    public static ContactPhotoManager getInstance(Context context) {
+        if (sInstance == null) {
+            Context applicationContext = context.getApplicationContext();
+            sInstance = createContactPhotoManager(applicationContext);
+            applicationContext.registerComponentCallbacks(sInstance);
+            if (PermissionsUtil.hasContactsPermissions(context)) {
+                sInstance.preloadPhotosInBackground();
+            }
+        }
+        return sInstance;
+    }
+
+    public static synchronized ContactPhotoManager createContactPhotoManager(Context context) {
+        return new ContactPhotoManagerImpl(context);
+    }
+
+    @VisibleForTesting
+    public static void injectContactPhotoManagerForTesting(ContactPhotoManager photoManager) {
+        sInstance = photoManager;
+    }
+
+    /**
+     * Load thumbnail image into the supplied image view. If the photo is already cached,
+     * it is displayed immediately.  Otherwise a request is sent to load the photo
+     * from the database.
+     */
+    public abstract void loadThumbnail(ImageView view, long photoId, boolean darkTheme,
+            boolean isCircular, DefaultImageRequest defaultImageRequest,
+            DefaultImageProvider defaultProvider);
+
+    /**
+     * Calls {@link #loadThumbnail(ImageView, long, boolean, DefaultImageRequest,
+     * DefaultImageProvider)} using the {@link DefaultImageProvider} {@link #DEFAULT_AVATAR}.
+     */
+    public final void loadThumbnail(ImageView view, long photoId, boolean darkTheme,
+            boolean isCircular, DefaultImageRequest defaultImageRequest) {
+        loadThumbnail(view, photoId, darkTheme, isCircular, defaultImageRequest, DEFAULT_AVATAR);
+    }
+
+
+    /**
+     * Load photo into the supplied image view. If the photo is already cached,
+     * it is displayed immediately. Otherwise a request is sent to load the photo
+     * from the location specified by the URI.
+     *
+     * @param view The target view
+     * @param photoUri The uri of the photo to load
+     * @param requestedExtent Specifies an approximate Max(width, height) of the targetView.
+     * This is useful if the source image can be a lot bigger that the target, so that the decoding
+     * is done using efficient sampling. If requestedExtent is specified, no sampling of the image
+     * is performed
+     * @param darkTheme Whether the background is dark. This is used for default avatars
+     * @param defaultImageRequest {@link DefaultImageRequest} object that specifies how a default
+     * letter tile avatar should be drawn.
+     * @param defaultProvider The provider of default avatars (this is used if photoUri doesn't
+     * refer to an existing image)
+     */
+    public abstract void loadPhoto(ImageView view, Uri photoUri, int requestedExtent,
+            boolean darkTheme, boolean isCircular, DefaultImageRequest defaultImageRequest,
+            DefaultImageProvider defaultProvider);
+
+    /**
+     * Calls {@link #loadPhoto(ImageView, Uri, int, boolean, DefaultImageRequest,
+     * DefaultImageProvider)} with {@link #DEFAULT_AVATAR} and {@code null} display names and
+     * lookup keys.
+     *
+     * @param defaultImageRequest {@link DefaultImageRequest} object that specifies how a default
+     * letter tile avatar should be drawn.
+     */
+    public final void loadPhoto(ImageView view, Uri photoUri, int requestedExtent,
+            boolean darkTheme, boolean isCircular, DefaultImageRequest defaultImageRequest) {
+        loadPhoto(view, photoUri, requestedExtent, darkTheme, isCircular,
+                defaultImageRequest, DEFAULT_AVATAR);
+    }
+
+    /**
+     * Calls {@link #loadPhoto(ImageView, Uri, boolean, boolean, DefaultImageRequest,
+     * DefaultImageProvider)} with {@link #DEFAULT_AVATAR} and with the assumption, that
+     * the image is a thumbnail.
+     *
+     * @param defaultImageRequest {@link DefaultImageRequest} object that specifies how a default
+     * letter tile avatar should be drawn.
+     */
+    public final void loadDirectoryPhoto(ImageView view, Uri photoUri, boolean darkTheme,
+            boolean isCircular, DefaultImageRequest defaultImageRequest) {
+        loadPhoto(view, photoUri, -1, darkTheme, isCircular, defaultImageRequest, DEFAULT_AVATAR);
+    }
+
+    /**
+     * Remove photo from the supplied image view. This also cancels current pending load request
+     * inside this photo manager.
+     */
+    public abstract void removePhoto(ImageView view);
+
+    /**
+     * Cancels all pending requests to load photos asynchronously.
+     */
+    public abstract void cancelPendingRequests(View fragmentRootView);
+
+    /**
+     * Temporarily stops loading photos from the database.
+     */
+    public abstract void pause();
+
+    /**
+     * Resumes loading photos from the database.
+     */
+    public abstract void resume();
+
+    /**
+     * Marks all cached photos for reloading.  We can continue using cache but should
+     * also make sure the photos haven't changed in the background and notify the views
+     * if so.
+     */
+    public abstract void refreshCache();
+
+    /**
+     * Stores the given bitmap directly in the LRU bitmap cache.
+     * @param photoUri The URI of the photo (for future requests).
+     * @param bitmap The bitmap.
+     * @param photoBytes The bytes that were parsed to create the bitmap.
+     */
+    public abstract void cacheBitmap(Uri photoUri, Bitmap bitmap, byte[] photoBytes);
+
+    /**
+     * Initiates a background process that over time will fill up cache with
+     * preload photos.
+     */
+    public abstract void preloadPhotosInBackground();
+
+    // ComponentCallbacks2
+    @Override
+    public void onConfigurationChanged(Configuration newConfig) {
+    }
+
+    // ComponentCallbacks2
+    @Override
+    public void onLowMemory() {
+    }
+
+    // ComponentCallbacks2
+    @Override
+    public void onTrimMemory(int level) {
+    }
+}
+
+class ContactPhotoManagerImpl extends ContactPhotoManager implements Callback {
+    private static final String LOADER_THREAD_NAME = "ContactPhotoLoader";
+
+    private static final int FADE_TRANSITION_DURATION = 200;
+
+    /**
+     * Type of message sent by the UI thread to itself to indicate that some photos
+     * need to be loaded.
+     */
+    private static final int MESSAGE_REQUEST_LOADING = 1;
+
+    /**
+     * Type of message sent by the loader thread to indicate that some photos have
+     * been loaded.
+     */
+    private static final int MESSAGE_PHOTOS_LOADED = 2;
+
+    private static final String[] EMPTY_STRING_ARRAY = new String[0];
+
+    private static final String[] COLUMNS = new String[] { Photo._ID, Photo.PHOTO };
+
+    /**
+     * Dummy object used to indicate that a bitmap for a given key could not be stored in the
+     * cache.
+     */
+    private static final BitmapHolder BITMAP_UNAVAILABLE;
+
+    static {
+        BITMAP_UNAVAILABLE = new BitmapHolder(new byte[0], 0);
+        BITMAP_UNAVAILABLE.bitmapRef = new SoftReference<Bitmap>(null);
+    }
+
+    /**
+     * Maintains the state of a particular photo.
+     */
+    private static class BitmapHolder {
+        final byte[] bytes;
+        final int originalSmallerExtent;
+
+        volatile boolean fresh;
+        Bitmap bitmap;
+        Reference<Bitmap> bitmapRef;
+        int decodedSampleSize;
+
+        public BitmapHolder(byte[] bytes, int originalSmallerExtent) {
+            this.bytes = bytes;
+            this.fresh = true;
+            this.originalSmallerExtent = originalSmallerExtent;
+        }
+    }
+
+    private final Context mContext;
+
+    /**
+     * An LRU cache for bitmap holders. The cache contains bytes for photos just
+     * as they come from the database. Each holder has a soft reference to the
+     * actual bitmap.
+     */
+    private final LruCache<Object, BitmapHolder> mBitmapHolderCache;
+
+    /**
+     * {@code true} if ALL entries in {@link #mBitmapHolderCache} are NOT fresh.
+     */
+    private volatile boolean mBitmapHolderCacheAllUnfresh = true;
+
+    /**
+     * Cache size threshold at which bitmaps will not be preloaded.
+     */
+    private final int mBitmapHolderCacheRedZoneBytes;
+
+    /**
+     * Level 2 LRU cache for bitmaps. This is a smaller cache that holds
+     * the most recently used bitmaps to save time on decoding
+     * them from bytes (the bytes are stored in {@link #mBitmapHolderCache}.
+     */
+    private final LruCache<Object, Bitmap> mBitmapCache;
+
+    /**
+     * A map from ImageView to the corresponding photo ID or uri, encapsulated in a request.
+     * The request may swapped out before the photo loading request is started.
+     */
+    private final ConcurrentHashMap<ImageView, Request> mPendingRequests =
+            new ConcurrentHashMap<ImageView, Request>();
+
+    /**
+     * Handler for messages sent to the UI thread.
+     */
+    private final Handler mMainThreadHandler = new Handler(this);
+
+    /**
+     * Thread responsible for loading photos from the database. Created upon
+     * the first request.
+     */
+    private LoaderThread mLoaderThread;
+
+    /**
+     * A gate to make sure we only send one instance of MESSAGE_PHOTOS_NEEDED at a time.
+     */
+    private boolean mLoadingRequested;
+
+    /**
+     * Flag indicating if the image loading is paused.
+     */
+    private boolean mPaused;
+
+    /** Cache size for {@link #mBitmapHolderCache} for devices with "large" RAM. */
+    private static final int HOLDER_CACHE_SIZE = 2000000;
+
+    /** Cache size for {@link #mBitmapCache} for devices with "large" RAM. */
+    private static final int BITMAP_CACHE_SIZE = 36864 * 48; // 1728K
+
+    /** Height/width of a thumbnail image */
+    private static int mThumbnailSize;
+
+    /** For debug: How many times we had to reload cached photo for a stale entry */
+    private final AtomicInteger mStaleCacheOverwrite = new AtomicInteger();
+
+    /** For debug: How many times we had to reload cached photo for a fresh entry.  Should be 0. */
+    private final AtomicInteger mFreshCacheOverwrite = new AtomicInteger();
+
+    /**
+     * The user agent string to use when loading URI based photos.
+     */
+    private String mUserAgent;
+
+    public ContactPhotoManagerImpl(Context context) {
+        mContext = context;
+
+        final ActivityManager am = ((ActivityManager) context.getSystemService(
+                Context.ACTIVITY_SERVICE));
+
+        final float cacheSizeAdjustment = (am.isLowRamDevice()) ? 0.5f : 1.0f;
+
+        final int bitmapCacheSize = (int) (cacheSizeAdjustment * BITMAP_CACHE_SIZE);
+        mBitmapCache = new LruCache<Object, Bitmap>(bitmapCacheSize) {
+            @Override protected int sizeOf(Object key, Bitmap value) {
+                return value.getByteCount();
+            }
+
+            @Override protected void entryRemoved(
+                    boolean evicted, Object key, Bitmap oldValue, Bitmap newValue) {
+                if (DEBUG) dumpStats();
+            }
+        };
+        final int holderCacheSize = (int) (cacheSizeAdjustment * HOLDER_CACHE_SIZE);
+        mBitmapHolderCache = new LruCache<Object, BitmapHolder>(holderCacheSize) {
+            @Override protected int sizeOf(Object key, BitmapHolder value) {
+                return value.bytes != null ? value.bytes.length : 0;
+            }
+
+            @Override protected void entryRemoved(
+                    boolean evicted, Object key, BitmapHolder oldValue, BitmapHolder newValue) {
+                if (DEBUG) dumpStats();
+            }
+        };
+        mBitmapHolderCacheRedZoneBytes = (int) (holderCacheSize * 0.75);
+        Log.i(TAG, "Cache adj: " + cacheSizeAdjustment);
+        if (DEBUG) {
+            Log.d(TAG, "Cache size: " + btk(mBitmapHolderCache.maxSize())
+                    + " + " + btk(mBitmapCache.maxSize()));
+        }
+
+        mThumbnailSize = context.getResources().getDimensionPixelSize(
+                R.dimen.contact_browser_list_item_photo_size);
+
+        // Get a user agent string to use for URI photo requests.
+        mUserAgent = UserAgentGenerator.getUserAgent(context);
+        if (mUserAgent == null) {
+            mUserAgent = "";
+        }
+    }
+
+    /** Converts bytes to K bytes, rounding up.  Used only for debug log. */
+    private static String btk(int bytes) {
+        return ((bytes + 1023) / 1024) + "K";
+    }
+
+    private static final int safeDiv(int dividend, int divisor) {
+        return (divisor  == 0) ? 0 : (dividend / divisor);
+    }
+
+    /**
+     * Dump cache stats on logcat.
+     */
+    private void dumpStats() {
+        if (!DEBUG) return;
+        {
+            int numHolders = 0;
+            int rawBytes = 0;
+            int bitmapBytes = 0;
+            int numBitmaps = 0;
+            for (BitmapHolder h : mBitmapHolderCache.snapshot().values()) {
+                numHolders++;
+                if (h.bytes != null) {
+                    rawBytes += h.bytes.length;
+                }
+                Bitmap b = h.bitmapRef != null ? h.bitmapRef.get() : null;
+                if (b != null) {
+                    numBitmaps++;
+                    bitmapBytes += b.getByteCount();
+                }
+            }
+            Log.d(TAG, "L1: " + btk(rawBytes) + " + " + btk(bitmapBytes) + " = "
+                    + btk(rawBytes + bitmapBytes) + ", " + numHolders + " holders, "
+                    + numBitmaps + " bitmaps, avg: "
+                    + btk(safeDiv(rawBytes, numHolders))
+                    + "," + btk(safeDiv(bitmapBytes,numBitmaps)));
+            Log.d(TAG, "L1 Stats: " + mBitmapHolderCache.toString()
+                    + ", overwrite: fresh=" + mFreshCacheOverwrite.get()
+                    + " stale=" + mStaleCacheOverwrite.get());
+        }
+
+        {
+            int numBitmaps = 0;
+            int bitmapBytes = 0;
+            for (Bitmap b : mBitmapCache.snapshot().values()) {
+                numBitmaps++;
+                bitmapBytes += b.getByteCount();
+            }
+            Log.d(TAG, "L2: " + btk(bitmapBytes) + ", " + numBitmaps + " bitmaps"
+                    + ", avg: " + btk(safeDiv(bitmapBytes, numBitmaps)));
+            // We don't get from L2 cache, so L2 stats is meaningless.
+        }
+    }
+
+    @Override
+    public void onTrimMemory(int level) {
+        if (DEBUG) Log.d(TAG, "onTrimMemory: " + level);
+        if (level >= ComponentCallbacks2.TRIM_MEMORY_MODERATE) {
+            // Clear the caches.  Note all pending requests will be removed too.
+            clear();
+        }
+    }
+
+    @Override
+    public void preloadPhotosInBackground() {
+        ensureLoaderThread();
+        mLoaderThread.requestPreloading();
+    }
+
+    @Override
+    public void loadThumbnail(ImageView view, long photoId, boolean darkTheme, boolean isCircular,
+            DefaultImageRequest defaultImageRequest, DefaultImageProvider defaultProvider) {
+        if (photoId == 0) {
+            // No photo is needed
+            defaultProvider.applyDefaultImage(view, -1, darkTheme, defaultImageRequest);
+            mPendingRequests.remove(view);
+        } else {
+            if (DEBUG) Log.d(TAG, "loadPhoto request: " + photoId);
+            loadPhotoByIdOrUri(view, Request.createFromThumbnailId(photoId, darkTheme, isCircular,
+                    defaultProvider, defaultImageRequest));
+        }
+    }
+
+    @Override
+    public void loadPhoto(ImageView view, Uri photoUri, int requestedExtent, boolean darkTheme,
+            boolean isCircular, DefaultImageRequest defaultImageRequest,
+            DefaultImageProvider defaultProvider) {
+        if (photoUri == null) {
+            // No photo is needed
+            defaultProvider.applyDefaultImage(view, requestedExtent, darkTheme,
+                    defaultImageRequest);
+            mPendingRequests.remove(view);
+        } else {
+            if (DEBUG) Log.d(TAG, "loadPhoto request: " + photoUri);
+            if (isDefaultImageUri(photoUri)) {
+                createAndApplyDefaultImageForUri(view, photoUri, requestedExtent, darkTheme,
+                        isCircular, defaultProvider);
+            } else {
+                loadPhotoByIdOrUri(view, Request.createFromUri(photoUri, requestedExtent,
+                        darkTheme, isCircular, defaultProvider, defaultImageRequest));
+            }
+        }
+    }
+
+    private void createAndApplyDefaultImageForUri(ImageView view, Uri uri, int requestedExtent,
+            boolean darkTheme, boolean isCircular, DefaultImageProvider defaultProvider) {
+        DefaultImageRequest request = getDefaultImageRequestFromUri(uri);
+        request.isCircular = isCircular;
+        defaultProvider.applyDefaultImage(view, requestedExtent, darkTheme, request);
+    }
+
+    private void loadPhotoByIdOrUri(ImageView view, Request request) {
+        boolean loaded = loadCachedPhoto(view, request, false);
+        if (loaded) {
+            mPendingRequests.remove(view);
+        } else {
+            mPendingRequests.put(view, request);
+            if (!mPaused) {
+                // Send a request to start loading photos
+                requestLoading();
+            }
+        }
+    }
+
+    @Override
+    public void removePhoto(ImageView view) {
+        view.setImageDrawable(null);
+        mPendingRequests.remove(view);
+    }
+
+
+    /**
+     * Cancels pending requests to load photos asynchronously for views inside
+     * {@param fragmentRootView}. If {@param fragmentRootView} is null, cancels all requests.
+     */
+    @Override
+    public void cancelPendingRequests(View fragmentRootView) {
+        if (fragmentRootView == null) {
+            mPendingRequests.clear();
+            return;
+        }
+        final Iterator<Entry<ImageView, Request>> iterator = mPendingRequests.entrySet().iterator();
+        while (iterator.hasNext()) {
+            final ImageView imageView = iterator.next().getKey();
+            // If an ImageView is orphaned (currently scrap) or a child of fragmentRootView, then
+            // we can safely remove its request.
+            if (imageView.getParent() == null || isChildView(fragmentRootView, imageView)) {
+                iterator.remove();
+            }
+        }
+    }
+
+    private static boolean isChildView(View parent, View potentialChild) {
+        return potentialChild.getParent() != null && (potentialChild.getParent() == parent || (
+                potentialChild.getParent() instanceof ViewGroup && isChildView(parent,
+                        (ViewGroup) potentialChild.getParent())));
+    }
+
+    @Override
+    public void refreshCache() {
+        if (mBitmapHolderCacheAllUnfresh) {
+            if (DEBUG) Log.d(TAG, "refreshCache -- no fresh entries.");
+            return;
+        }
+        if (DEBUG) Log.d(TAG, "refreshCache");
+        mBitmapHolderCacheAllUnfresh = true;
+        for (BitmapHolder holder : mBitmapHolderCache.snapshot().values()) {
+            if (holder != BITMAP_UNAVAILABLE) {
+                holder.fresh = false;
+            }
+        }
+    }
+
+    /**
+     * Checks if the photo is present in cache.  If so, sets the photo on the view.
+     *
+     * @return false if the photo needs to be (re)loaded from the provider.
+     */
+    private boolean loadCachedPhoto(ImageView view, Request request, boolean fadeIn) {
+        BitmapHolder holder = mBitmapHolderCache.get(request.getKey());
+        if (holder == null) {
+            // The bitmap has not been loaded ==> show default avatar
+            request.applyDefaultImage(view, request.mIsCircular);
+            return false;
+        }
+
+        if (holder.bytes == null || holder.bytes.length == 0) {
+            request.applyDefaultImage(view, request.mIsCircular);
+            return holder.fresh;
+        }
+
+        Bitmap cachedBitmap = holder.bitmapRef == null ? null : holder.bitmapRef.get();
+        if (cachedBitmap == null) {
+            if (holder.bytes.length < 8 * 1024) {
+                // Small thumbnails are usually quick to inflate. Let's do that on the UI thread
+                inflateBitmap(holder, request.getRequestedExtent());
+                cachedBitmap = holder.bitmap;
+                if (cachedBitmap == null) return false;
+            } else {
+                // This is bigger data. Let's send that back to the Loader so that we can
+                // inflate this in the background
+                request.applyDefaultImage(view, request.mIsCircular);
+                return false;
+            }
+        }
+
+        final Drawable previousDrawable = view.getDrawable();
+        if (fadeIn && previousDrawable != null) {
+            final Drawable[] layers = new Drawable[2];
+            // Prevent cascade of TransitionDrawables.
+            if (previousDrawable instanceof TransitionDrawable) {
+                final TransitionDrawable previousTransitionDrawable =
+                        (TransitionDrawable) previousDrawable;
+                layers[0] = previousTransitionDrawable.getDrawable(
+                        previousTransitionDrawable.getNumberOfLayers() - 1);
+            } else {
+                layers[0] = previousDrawable;
+            }
+            layers[1] = getDrawableForBitmap(mContext.getResources(), cachedBitmap, request);
+            TransitionDrawable drawable = new TransitionDrawable(layers);
+            view.setImageDrawable(drawable);
+            drawable.startTransition(FADE_TRANSITION_DURATION);
+        } else {
+            view.setImageDrawable(
+                    getDrawableForBitmap(mContext.getResources(), cachedBitmap, request));
+        }
+
+        // Put the bitmap in the LRU cache. But only do this for images that are small enough
+        // (we require that at least six of those can be cached at the same time)
+        if (cachedBitmap.getByteCount() < mBitmapCache.maxSize() / 6) {
+            mBitmapCache.put(request.getKey(), cachedBitmap);
+        }
+
+        // Soften the reference
+        holder.bitmap = null;
+
+        return holder.fresh;
+    }
+
+    /**
+     * Given a bitmap, returns a drawable that is configured to display the bitmap based on the
+     * specified request.
+     */
+    private Drawable getDrawableForBitmap(Resources resources, Bitmap bitmap, Request request) {
+        if (request.mIsCircular) {
+            final RoundedBitmapDrawable drawable =
+                    RoundedBitmapDrawableFactory.create(resources, bitmap);
+            drawable.setAntiAlias(true);
+            drawable.setCornerRadius(bitmap.getHeight() / 2);
+            return drawable;
+        } else {
+            return new BitmapDrawable(resources, bitmap);
+        }
+    }
+
+    /**
+     * If necessary, decodes bytes stored in the holder to Bitmap.  As long as the
+     * bitmap is held either by {@link #mBitmapCache} or by a soft reference in
+     * the holder, it will not be necessary to decode the bitmap.
+     */
+    private static void inflateBitmap(BitmapHolder holder, int requestedExtent) {
+        final int sampleSize =
+                BitmapUtil.findOptimalSampleSize(holder.originalSmallerExtent, requestedExtent);
+        byte[] bytes = holder.bytes;
+        if (bytes == null || bytes.length == 0) {
+            return;
+        }
+
+        if (sampleSize == holder.decodedSampleSize) {
+            // Check the soft reference.  If will be retained if the bitmap is also
+            // in the LRU cache, so we don't need to check the LRU cache explicitly.
+            if (holder.bitmapRef != null) {
+                holder.bitmap = holder.bitmapRef.get();
+                if (holder.bitmap != null) {
+                    return;
+                }
+            }
+        }
+
+        try {
+            Bitmap bitmap = BitmapUtil.decodeBitmapFromBytes(bytes, sampleSize);
+
+            // TODO: As a temporary workaround while framework support is being added to
+            // clip non-square bitmaps into a perfect circle, manually crop the bitmap into
+            // into a square if it will be displayed as a thumbnail so that it can be cropped
+            // into a circle.
+            final int height = bitmap.getHeight();
+            final int width = bitmap.getWidth();
+
+            // The smaller dimension of a scaled bitmap can range from anywhere from 0 to just
+            // below twice the length of a thumbnail image due to the way we calculate the optimal
+            // sample size.
+            if (height != width && Math.min(height, width) <= mThumbnailSize * 2) {
+                final int dimension = Math.min(height, width);
+                bitmap = ThumbnailUtils.extractThumbnail(bitmap, dimension, dimension);
+            }
+            // make bitmap mutable and draw size onto it
+            if (DEBUG_SIZES) {
+                Bitmap original = bitmap;
+                bitmap = bitmap.copy(bitmap.getConfig(), true);
+                original.recycle();
+                Canvas canvas = new Canvas(bitmap);
+                Paint paint = new Paint();
+                paint.setTextSize(16);
+                paint.setColor(Color.BLUE);
+                paint.setStyle(Style.FILL);
+                canvas.drawRect(0.0f, 0.0f, 50.0f, 20.0f, paint);
+                paint.setColor(Color.WHITE);
+                paint.setAntiAlias(true);
+                canvas.drawText(bitmap.getWidth() + "/" + sampleSize, 0, 15, paint);
+            }
+
+            holder.decodedSampleSize = sampleSize;
+            holder.bitmap = bitmap;
+            holder.bitmapRef = new SoftReference<Bitmap>(bitmap);
+            if (DEBUG) {
+                Log.d(TAG, "inflateBitmap " + btk(bytes.length) + " -> "
+                        + bitmap.getWidth() + "x" + bitmap.getHeight()
+                        + ", " + btk(bitmap.getByteCount()));
+            }
+        } catch (OutOfMemoryError e) {
+            // Do nothing - the photo will appear to be missing
+        }
+    }
+
+    public void clear() {
+        if (DEBUG) Log.d(TAG, "clear");
+        mPendingRequests.clear();
+        mBitmapHolderCache.evictAll();
+        mBitmapCache.evictAll();
+    }
+
+    @Override
+    public void pause() {
+        mPaused = true;
+    }
+
+    @Override
+    public void resume() {
+        mPaused = false;
+        if (DEBUG) dumpStats();
+        if (!mPendingRequests.isEmpty()) {
+            requestLoading();
+        }
+    }
+
+    /**
+     * Sends a message to this thread itself to start loading images.  If the current
+     * view contains multiple image views, all of those image views will get a chance
+     * to request their respective photos before any of those requests are executed.
+     * This allows us to load images in bulk.
+     */
+    private void requestLoading() {
+        if (!mLoadingRequested) {
+            mLoadingRequested = true;
+            mMainThreadHandler.sendEmptyMessage(MESSAGE_REQUEST_LOADING);
+        }
+    }
+
+    /**
+     * Processes requests on the main thread.
+     */
+    @Override
+    public boolean handleMessage(Message msg) {
+        switch (msg.what) {
+            case MESSAGE_REQUEST_LOADING: {
+                mLoadingRequested = false;
+                if (!mPaused) {
+                    ensureLoaderThread();
+                    mLoaderThread.requestLoading();
+                }
+                return true;
+            }
+
+            case MESSAGE_PHOTOS_LOADED: {
+                if (!mPaused) {
+                    processLoadedImages();
+                }
+                if (DEBUG) dumpStats();
+                return true;
+            }
+        }
+        return false;
+    }
+
+    public void ensureLoaderThread() {
+        if (mLoaderThread == null) {
+            mLoaderThread = new LoaderThread(mContext.getContentResolver());
+            mLoaderThread.start();
+        }
+    }
+
+    /**
+     * Goes over pending loading requests and displays loaded photos.  If some of the
+     * photos still haven't been loaded, sends another request for image loading.
+     */
+    private void processLoadedImages() {
+        final Iterator<Entry<ImageView, Request>> iterator = mPendingRequests.entrySet().iterator();
+        while (iterator.hasNext()) {
+            final Entry<ImageView, Request> entry = iterator.next();
+            // TODO: Temporarily disable contact photo fading in, until issues with
+            // RoundedBitmapDrawables overlapping the default image drawables are resolved.
+            final boolean loaded = loadCachedPhoto(entry.getKey(), entry.getValue(), false);
+            if (loaded) {
+                iterator.remove();
+            }
+        }
+
+        softenCache();
+
+        if (!mPendingRequests.isEmpty()) {
+            requestLoading();
+        }
+    }
+
+    /**
+     * Removes strong references to loaded bitmaps to allow them to be garbage collected
+     * if needed.  Some of the bitmaps will still be retained by {@link #mBitmapCache}.
+     */
+    private void softenCache() {
+        for (BitmapHolder holder : mBitmapHolderCache.snapshot().values()) {
+            holder.bitmap = null;
+        }
+    }
+
+    /**
+     * Stores the supplied bitmap in cache.
+     * bytes should be null to indicate a failure to load the photo. An empty byte[] signifies
+     * a successful load but no photo was available.
+     */
+    private void cacheBitmap(Object key, byte[] bytes, boolean preloading, int requestedExtent) {
+        if (DEBUG) {
+            BitmapHolder prev = mBitmapHolderCache.get(key);
+            if (prev != null && prev.bytes != null) {
+                Log.d(TAG, "Overwriting cache: key=" + key + (prev.fresh ? " FRESH" : " stale"));
+                if (prev.fresh) {
+                    mFreshCacheOverwrite.incrementAndGet();
+                } else {
+                    mStaleCacheOverwrite.incrementAndGet();
+                }
+            }
+            Log.d(TAG, "Caching data: key=" + key + ", " +
+                    (bytes == null ? "<null>" : btk(bytes.length)));
+        }
+        BitmapHolder holder = new BitmapHolder(bytes,
+                bytes == null ? -1 : BitmapUtil.getSmallerExtentFromBytes(bytes));
+
+        // Unless this image is being preloaded, decode it right away while
+        // we are still on the background thread.
+        if (!preloading) {
+            inflateBitmap(holder, requestedExtent);
+        }
+
+        if (bytes != null) {
+            mBitmapHolderCache.put(key, holder);
+            if (mBitmapHolderCache.get(key) != holder) {
+                Log.w(TAG, "Bitmap too big to fit in cache.");
+                mBitmapHolderCache.put(key, BITMAP_UNAVAILABLE);
+            }
+        } else {
+            mBitmapHolderCache.put(key, BITMAP_UNAVAILABLE);
+        }
+
+        mBitmapHolderCacheAllUnfresh = false;
+    }
+
+    @Override
+    public void cacheBitmap(Uri photoUri, Bitmap bitmap, byte[] photoBytes) {
+        final int smallerExtent = Math.min(bitmap.getWidth(), bitmap.getHeight());
+        // We can pretend here that the extent of the photo was the size that we originally
+        // requested
+        Request request = Request.createFromUri(photoUri, smallerExtent, false /* darkTheme */,
+                false /* isCircular */ , DEFAULT_AVATAR);
+        BitmapHolder holder = new BitmapHolder(photoBytes, smallerExtent);
+        holder.bitmapRef = new SoftReference<Bitmap>(bitmap);
+        mBitmapHolderCache.put(request.getKey(), holder);
+        mBitmapHolderCacheAllUnfresh = false;
+        mBitmapCache.put(request.getKey(), bitmap);
+    }
+
+    /**
+     * Populates an array of photo IDs that need to be loaded. Also decodes bitmaps that we have
+     * already loaded
+     */
+    private void obtainPhotoIdsAndUrisToLoad(Set<Long> photoIds,
+            Set<String> photoIdsAsStrings, Set<Request> uris) {
+        photoIds.clear();
+        photoIdsAsStrings.clear();
+        uris.clear();
+
+        boolean jpegsDecoded = false;
+
+        /*
+         * Since the call is made from the loader thread, the map could be
+         * changing during the iteration. That's not really a problem:
+         * ConcurrentHashMap will allow those changes to happen without throwing
+         * exceptions. Since we may miss some requests in the situation of
+         * concurrent change, we will need to check the map again once loading
+         * is complete.
+         */
+        Iterator<Request> iterator = mPendingRequests.values().iterator();
+        while (iterator.hasNext()) {
+            Request request = iterator.next();
+            final BitmapHolder holder = mBitmapHolderCache.get(request.getKey());
+            if (holder == BITMAP_UNAVAILABLE) {
+                continue;
+            }
+            if (holder != null && holder.bytes != null && holder.fresh &&
+                    (holder.bitmapRef == null || holder.bitmapRef.get() == null)) {
+                // This was previously loaded but we don't currently have the inflated Bitmap
+                inflateBitmap(holder, request.getRequestedExtent());
+                jpegsDecoded = true;
+            } else {
+                if (holder == null || !holder.fresh) {
+                    if (request.isUriRequest()) {
+                        uris.add(request);
+                    } else {
+                        photoIds.add(request.getId());
+                        photoIdsAsStrings.add(String.valueOf(request.mId));
+                    }
+                }
+            }
+        }
+
+        if (jpegsDecoded) mMainThreadHandler.sendEmptyMessage(MESSAGE_PHOTOS_LOADED);
+    }
+
+    /**
+     * The thread that performs loading of photos from the database.
+     */
+    private class LoaderThread extends HandlerThread implements Callback {
+        private static final int BUFFER_SIZE = 1024*16;
+        private static final int MESSAGE_PRELOAD_PHOTOS = 0;
+        private static final int MESSAGE_LOAD_PHOTOS = 1;
+
+        /**
+         * A pause between preload batches that yields to the UI thread.
+         */
+        private static final int PHOTO_PRELOAD_DELAY = 1000;
+
+        /**
+         * Number of photos to preload per batch.
+         */
+        private static final int PRELOAD_BATCH = 25;
+
+        /**
+         * Maximum number of photos to preload.  If the cache size is 2Mb and
+         * the expected average size of a photo is 4kb, then this number should be 2Mb/4kb = 500.
+         */
+        private static final int MAX_PHOTOS_TO_PRELOAD = 100;
+
+        private final ContentResolver mResolver;
+        private final StringBuilder mStringBuilder = new StringBuilder();
+        private final Set<Long> mPhotoIds = Sets.newHashSet();
+        private final Set<String> mPhotoIdsAsStrings = Sets.newHashSet();
+        private final Set<Request> mPhotoUris = Sets.newHashSet();
+        private final List<Long> mPreloadPhotoIds = Lists.newArrayList();
+
+        private Handler mLoaderThreadHandler;
+        private byte mBuffer[];
+
+        private static final int PRELOAD_STATUS_NOT_STARTED = 0;
+        private static final int PRELOAD_STATUS_IN_PROGRESS = 1;
+        private static final int PRELOAD_STATUS_DONE = 2;
+
+        private int mPreloadStatus = PRELOAD_STATUS_NOT_STARTED;
+
+        public LoaderThread(ContentResolver resolver) {
+            super(LOADER_THREAD_NAME);
+            mResolver = resolver;
+        }
+
+        public void ensureHandler() {
+            if (mLoaderThreadHandler == null) {
+                mLoaderThreadHandler = new Handler(getLooper(), this);
+            }
+        }
+
+        /**
+         * Kicks off preloading of the next batch of photos on the background thread.
+         * Preloading will happen after a delay: we want to yield to the UI thread
+         * as much as possible.
+         * <p>
+         * If preloading is already complete, does nothing.
+         */
+        public void requestPreloading() {
+            if (mPreloadStatus == PRELOAD_STATUS_DONE) {
+                return;
+            }
+
+            ensureHandler();
+            if (mLoaderThreadHandler.hasMessages(MESSAGE_LOAD_PHOTOS)) {
+                return;
+            }
+
+            mLoaderThreadHandler.sendEmptyMessageDelayed(
+                    MESSAGE_PRELOAD_PHOTOS, PHOTO_PRELOAD_DELAY);
+        }
+
+        /**
+         * Sends a message to this thread to load requested photos.  Cancels a preloading
+         * request, if any: we don't want preloading to impede loading of the photos
+         * we need to display now.
+         */
+        public void requestLoading() {
+            ensureHandler();
+            mLoaderThreadHandler.removeMessages(MESSAGE_PRELOAD_PHOTOS);
+            mLoaderThreadHandler.sendEmptyMessage(MESSAGE_LOAD_PHOTOS);
+        }
+
+        /**
+         * Receives the above message, loads photos and then sends a message
+         * to the main thread to process them.
+         */
+        @Override
+        public boolean handleMessage(Message msg) {
+            switch (msg.what) {
+                case MESSAGE_PRELOAD_PHOTOS:
+                    preloadPhotosInBackground();
+                    break;
+                case MESSAGE_LOAD_PHOTOS:
+                    loadPhotosInBackground();
+                    break;
+            }
+            return true;
+        }
+
+        /**
+         * The first time it is called, figures out which photos need to be preloaded.
+         * Each subsequent call preloads the next batch of photos and requests
+         * another cycle of preloading after a delay.  The whole process ends when
+         * we either run out of photos to preload or fill up cache.
+         */
+        private void preloadPhotosInBackground() {
+            if (mPreloadStatus == PRELOAD_STATUS_DONE) {
+                return;
+            }
+
+            if (mPreloadStatus == PRELOAD_STATUS_NOT_STARTED) {
+                queryPhotosForPreload();
+                if (mPreloadPhotoIds.isEmpty()) {
+                    mPreloadStatus = PRELOAD_STATUS_DONE;
+                } else {
+                    mPreloadStatus = PRELOAD_STATUS_IN_PROGRESS;
+                }
+                requestPreloading();
+                return;
+            }
+
+            if (mBitmapHolderCache.size() > mBitmapHolderCacheRedZoneBytes) {
+                mPreloadStatus = PRELOAD_STATUS_DONE;
+                return;
+            }
+
+            mPhotoIds.clear();
+            mPhotoIdsAsStrings.clear();
+
+            int count = 0;
+            int preloadSize = mPreloadPhotoIds.size();
+            while(preloadSize > 0 && mPhotoIds.size() < PRELOAD_BATCH) {
+                preloadSize--;
+                count++;
+                Long photoId = mPreloadPhotoIds.get(preloadSize);
+                mPhotoIds.add(photoId);
+                mPhotoIdsAsStrings.add(photoId.toString());
+                mPreloadPhotoIds.remove(preloadSize);
+            }
+
+            loadThumbnails(true);
+
+            if (preloadSize == 0) {
+                mPreloadStatus = PRELOAD_STATUS_DONE;
+            }
+
+            Log.v(TAG, "Preloaded " + count + " photos.  Cached bytes: "
+                    + mBitmapHolderCache.size());
+
+            requestPreloading();
+        }
+
+        private void queryPhotosForPreload() {
+            Cursor cursor = null;
+            try {
+                Uri uri = Contacts.CONTENT_URI.buildUpon().appendQueryParameter(
+                        ContactsContract.DIRECTORY_PARAM_KEY, String.valueOf(Directory.DEFAULT))
+                        .appendQueryParameter(ContactsContract.LIMIT_PARAM_KEY,
+                                String.valueOf(MAX_PHOTOS_TO_PRELOAD))
+                        .build();
+                cursor = mResolver.query(uri, new String[] { Contacts.PHOTO_ID },
+                        Contacts.PHOTO_ID + " NOT NULL AND " + Contacts.PHOTO_ID + "!=0",
+                        null,
+                        Contacts.STARRED + " DESC, " + Contacts.LAST_TIME_CONTACTED + " DESC");
+
+                if (cursor != null) {
+                    while (cursor.moveToNext()) {
+                        // Insert them in reverse order, because we will be taking
+                        // them from the end of the list for loading.
+                        mPreloadPhotoIds.add(0, cursor.getLong(0));
+                    }
+                }
+            } finally {
+                if (cursor != null) {
+                    cursor.close();
+                }
+            }
+        }
+
+        private void loadPhotosInBackground() {
+            if (!PermissionsUtil.hasPermission(mContext,
+                    android.Manifest.permission.READ_CONTACTS)) {
+                return;
+            }
+            obtainPhotoIdsAndUrisToLoad(mPhotoIds, mPhotoIdsAsStrings, mPhotoUris);
+            loadThumbnails(false);
+            loadUriBasedPhotos();
+            requestPreloading();
+        }
+
+        /** Loads thumbnail photos with ids */
+        private void loadThumbnails(boolean preloading) {
+            if (mPhotoIds.isEmpty()) {
+                return;
+            }
+
+            // Remove loaded photos from the preload queue: we don't want
+            // the preloading process to load them again.
+            if (!preloading && mPreloadStatus == PRELOAD_STATUS_IN_PROGRESS) {
+                for (Long id : mPhotoIds) {
+                    mPreloadPhotoIds.remove(id);
+                }
+                if (mPreloadPhotoIds.isEmpty()) {
+                    mPreloadStatus = PRELOAD_STATUS_DONE;
+                }
+            }
+
+            mStringBuilder.setLength(0);
+            mStringBuilder.append(Photo._ID + " IN(");
+            for (int i = 0; i < mPhotoIds.size(); i++) {
+                if (i != 0) {
+                    mStringBuilder.append(',');
+                }
+                mStringBuilder.append('?');
+            }
+            mStringBuilder.append(')');
+
+            Cursor cursor = null;
+            try {
+                if (DEBUG) Log.d(TAG, "Loading " + TextUtils.join(",", mPhotoIdsAsStrings));
+                cursor = mResolver.query(Data.CONTENT_URI,
+                        COLUMNS,
+                        mStringBuilder.toString(),
+                        mPhotoIdsAsStrings.toArray(EMPTY_STRING_ARRAY),
+                        null);
+
+                if (cursor != null) {
+                    while (cursor.moveToNext()) {
+                        Long id = cursor.getLong(0);
+                        byte[] bytes = cursor.getBlob(1);
+                        if (bytes == null) {
+                            bytes = new byte[0];
+                        }
+                        cacheBitmap(id, bytes, preloading, -1);
+                        mPhotoIds.remove(id);
+                    }
+                }
+            } finally {
+                if (cursor != null) {
+                    cursor.close();
+                }
+            }
+
+            // Remaining photos were not found in the contacts database (but might be in profile).
+            for (Long id : mPhotoIds) {
+                if (ContactsContract.isProfileId(id)) {
+                    Cursor profileCursor = null;
+                    try {
+                        profileCursor = mResolver.query(
+                                ContentUris.withAppendedId(Data.CONTENT_URI, id),
+                                COLUMNS, null, null, null);
+                        if (profileCursor != null && profileCursor.moveToFirst()) {
+                            byte[] bytes = profileCursor.getBlob(1);
+                            if (bytes == null) {
+                                bytes = new byte[0];
+                            }
+                            cacheBitmap(profileCursor.getLong(0), bytes, preloading, -1);
+                        } else {
+                            // Couldn't load a photo this way either.
+                            cacheBitmap(id, null, preloading, -1);
+                        }
+                    } finally {
+                        if (profileCursor != null) {
+                            profileCursor.close();
+                        }
+                    }
+                } else {
+                    // Not a profile photo and not found - mark the cache accordingly
+                    cacheBitmap(id, null, preloading, -1);
+                }
+            }
+
+            mMainThreadHandler.sendEmptyMessage(MESSAGE_PHOTOS_LOADED);
+        }
+
+        /**
+         * Loads photos referenced with Uris. Those can be remote thumbnails
+         * (from directory searches), display photos etc
+         */
+        private void loadUriBasedPhotos() {
+            for (Request uriRequest : mPhotoUris) {
+                // Keep the original URI and use this to key into the cache.  Failure to do so will
+                // result in an image being continually reloaded into cache if the original URI
+                // has a contact type encodedFragment (eg nearby places business photo URLs).
+                Uri originalUri = uriRequest.getUri();
+
+                // Strip off the "contact type" we added to the URI to ensure it was identifiable as
+                // a business photo -- there is no need to pass this on to the server.
+                Uri uri = ContactPhotoManager.removeContactType(originalUri);
+
+                if (mBuffer == null) {
+                    mBuffer = new byte[BUFFER_SIZE];
+                }
+                try {
+                    if (DEBUG) Log.d(TAG, "Loading " + uri);
+                    final String scheme = uri.getScheme();
+                    InputStream is = null;
+                    if (scheme.equals("http") || scheme.equals("https")) {
+                        TrafficStats.setThreadStatsTag(TrafficStatsTags.CONTACT_PHOTO_DOWNLOAD_TAG);
+                        final HttpURLConnection connection =
+                                (HttpURLConnection) new URL(uri.toString()).openConnection();
+
+                        // Include the user agent if it is specified.
+                        if (!TextUtils.isEmpty(mUserAgent)) {
+                            connection.setRequestProperty("User-Agent", mUserAgent);
+                        }
+                        try {
+                            is = connection.getInputStream();
+                        } catch (IOException e) {
+                            connection.disconnect();
+                            is = null;
+                        }
+                        TrafficStats.clearThreadStatsTag();
+                    } else {
+                        is = mResolver.openInputStream(uri);
+                    }
+                    if (is != null) {
+                        ByteArrayOutputStream baos = new ByteArrayOutputStream();
+                        try {
+                            int size;
+                            while ((size = is.read(mBuffer)) != -1) {
+                                baos.write(mBuffer, 0, size);
+                            }
+                        } finally {
+                            is.close();
+                        }
+                        cacheBitmap(originalUri, baos.toByteArray(), false,
+                                uriRequest.getRequestedExtent());
+                        mMainThreadHandler.sendEmptyMessage(MESSAGE_PHOTOS_LOADED);
+                    } else {
+                        Log.v(TAG, "Cannot load photo " + uri);
+                        cacheBitmap(originalUri, null, false, uriRequest.getRequestedExtent());
+                    }
+                } catch (final Exception | OutOfMemoryError ex) {
+                    Log.v(TAG, "Cannot load photo " + uri, ex);
+                    cacheBitmap(originalUri, null, false, uriRequest.getRequestedExtent());
+                }
+            }
+        }
+    }
+
+    /**
+     * A holder for either a Uri or an id and a flag whether this was requested for the dark or
+     * light theme
+     */
+    private static final class Request {
+        private final long mId;
+        private final Uri mUri;
+        private final boolean mDarkTheme;
+        private final int mRequestedExtent;
+        private final DefaultImageProvider mDefaultProvider;
+        private final DefaultImageRequest mDefaultRequest;
+        /**
+         * Whether or not the contact photo is to be displayed as a circle
+         */
+        private final boolean mIsCircular;
+
+        private Request(long id, Uri uri, int requestedExtent, boolean darkTheme,
+                boolean isCircular, DefaultImageProvider defaultProvider,
+                DefaultImageRequest defaultRequest) {
+            mId = id;
+            mUri = uri;
+            mDarkTheme = darkTheme;
+            mIsCircular = isCircular;
+            mRequestedExtent = requestedExtent;
+            mDefaultProvider = defaultProvider;
+            mDefaultRequest = defaultRequest;
+        }
+
+        public static Request createFromThumbnailId(long id, boolean darkTheme, boolean isCircular,
+                DefaultImageProvider defaultProvider, DefaultImageRequest defaultRequest) {
+            return new Request(id, null /* no URI */, -1, darkTheme, isCircular, defaultProvider,
+                    defaultRequest);
+        }
+
+        public static Request createFromUri(Uri uri, int requestedExtent, boolean darkTheme,
+                boolean isCircular, DefaultImageProvider defaultProvider) {
+            return createFromUri(uri, requestedExtent, darkTheme, isCircular, defaultProvider,
+                    /* defaultRequest */ null);
+        }
+
+        public static Request createFromUri(Uri uri, int requestedExtent, boolean darkTheme,
+                boolean isCircular, DefaultImageProvider defaultProvider,
+                DefaultImageRequest defaultRequest) {
+            return new Request(0 /* no ID */, uri, requestedExtent, darkTheme, isCircular,
+                    defaultProvider, defaultRequest);
+        }
+
+        public boolean isUriRequest() {
+            return mUri != null;
+        }
+
+        public Uri getUri() {
+            return mUri;
+        }
+
+        public long getId() {
+            return mId;
+        }
+
+        public int getRequestedExtent() {
+            return mRequestedExtent;
+        }
+
+        @Override
+        public int hashCode() {
+            final int prime = 31;
+            int result = 1;
+            result = prime * result + (int) (mId ^ (mId >>> 32));
+            result = prime * result + mRequestedExtent;
+            result = prime * result + ((mUri == null) ? 0 : mUri.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;
+            final Request that = (Request) obj;
+            if (mId != that.mId) return false;
+            if (mRequestedExtent != that.mRequestedExtent) return false;
+            if (!UriUtils.areEqual(mUri, that.mUri)) return false;
+            // Don't compare equality of mDarkTheme because it is only used in the default contact
+            // photo case. When the contact does have a photo, the contact photo is the same
+            // regardless of mDarkTheme, so we shouldn't need to put the photo request on the queue
+            // twice.
+            return true;
+        }
+
+        public Object getKey() {
+            return mUri == null ? mId : mUri;
+        }
+
+        /**
+         * Applies the default image to the current view. If the request is URI-based, looks for
+         * the contact type encoded fragment to determine if this is a request for a business photo,
+         * in which case we will load the default business photo.
+         *
+         * @param view The current image view to apply the image to.
+         * @param isCircular Whether the image is circular or not.
+         */
+        public void applyDefaultImage(ImageView view, boolean isCircular) {
+            final DefaultImageRequest request;
+
+            if (mDefaultRequest == null) {
+                if (isCircular) {
+                    request = ContactPhotoManager.isBusinessContactUri(mUri)
+                            ? DefaultImageRequest.EMPTY_CIRCULAR_BUSINESS_IMAGE_REQUEST
+                            : DefaultImageRequest.EMPTY_CIRCULAR_DEFAULT_IMAGE_REQUEST;
+                } else {
+                    request = ContactPhotoManager.isBusinessContactUri(mUri)
+                            ? DefaultImageRequest.EMPTY_DEFAULT_BUSINESS_IMAGE_REQUEST
+                            : DefaultImageRequest.EMPTY_DEFAULT_IMAGE_REQUEST;
+                }
+            } else {
+                request = mDefaultRequest;
+            }
+            mDefaultProvider.applyDefaultImage(view, mRequestedExtent, mDarkTheme, request);
+        }
+    }
+}