Merge "Introduce CDM device presence base on UUID" into main
diff --git a/core/api/current.txt b/core/api/current.txt
index 671956d..25e93ce8 100644
--- a/core/api/current.txt
+++ b/core/api/current.txt
@@ -274,6 +274,7 @@
     field public static final String REQUEST_IGNORE_BATTERY_OPTIMIZATIONS = "android.permission.REQUEST_IGNORE_BATTERY_OPTIMIZATIONS";
     field public static final String REQUEST_INSTALL_PACKAGES = "android.permission.REQUEST_INSTALL_PACKAGES";
     field public static final String REQUEST_OBSERVE_COMPANION_DEVICE_PRESENCE = "android.permission.REQUEST_OBSERVE_COMPANION_DEVICE_PRESENCE";
+    field @FlaggedApi("android.companion.flags.device_presence") public static final String REQUEST_OBSERVE_DEVICE_UUID_PRESENCE = "android.permission.REQUEST_OBSERVE_DEVICE_UUID_PRESENCE";
     field public static final String REQUEST_PASSWORD_COMPLEXITY = "android.permission.REQUEST_PASSWORD_COMPLEXITY";
     field @Deprecated public static final String RESTART_PACKAGES = "android.permission.RESTART_PACKAGES";
     field public static final String RUN_USER_INITIATED_JOBS = "android.permission.RUN_USER_INITIATED_JOBS";
@@ -9696,8 +9697,10 @@
     method public void requestNotificationAccess(android.content.ComponentName);
     method @FlaggedApi("android.companion.association_tag") public void setAssociationTag(int, @NonNull String);
     method @RequiresPermission(android.Manifest.permission.REQUEST_OBSERVE_COMPANION_DEVICE_PRESENCE) public void startObservingDevicePresence(@NonNull String) throws android.companion.DeviceNotAssociatedException;
+    method @FlaggedApi("android.companion.device_presence") @RequiresPermission(android.Manifest.permission.REQUEST_OBSERVE_COMPANION_DEVICE_PRESENCE) public void startObservingDevicePresence(@NonNull android.companion.ObservingDevicePresenceRequest);
     method public void startSystemDataTransfer(int, @NonNull java.util.concurrent.Executor, @NonNull android.os.OutcomeReceiver<java.lang.Void,android.companion.CompanionException>) throws android.companion.DeviceNotAssociatedException;
     method @RequiresPermission(android.Manifest.permission.REQUEST_OBSERVE_COMPANION_DEVICE_PRESENCE) public void stopObservingDevicePresence(@NonNull String) throws android.companion.DeviceNotAssociatedException;
+    method @FlaggedApi("android.companion.device_presence") @RequiresPermission(android.Manifest.permission.REQUEST_OBSERVE_COMPANION_DEVICE_PRESENCE) public void stopObservingDevicePresence(@NonNull android.companion.ObservingDevicePresenceRequest);
     field public static final String EXTRA_ASSOCIATION = "android.companion.extra.ASSOCIATION";
     field @Deprecated public static final String EXTRA_DEVICE = "android.companion.extra.DEVICE";
     field public static final int FLAG_CALL_METADATA = 1; // 0x1
@@ -9725,13 +9728,7 @@
     method @MainThread public void onDeviceAppeared(@NonNull android.companion.AssociationInfo);
     method @Deprecated @MainThread public void onDeviceDisappeared(@NonNull String);
     method @MainThread public void onDeviceDisappeared(@NonNull android.companion.AssociationInfo);
-    method @FlaggedApi("android.companion.device_presence") @MainThread public void onDeviceEvent(@NonNull android.companion.AssociationInfo, int);
-    field @FlaggedApi("android.companion.device_presence") public static final int DEVICE_EVENT_BLE_APPEARED = 0; // 0x0
-    field @FlaggedApi("android.companion.device_presence") public static final int DEVICE_EVENT_BLE_DISAPPEARED = 1; // 0x1
-    field @FlaggedApi("android.companion.device_presence") public static final int DEVICE_EVENT_BT_CONNECTED = 2; // 0x2
-    field @FlaggedApi("android.companion.device_presence") public static final int DEVICE_EVENT_BT_DISCONNECTED = 3; // 0x3
-    field @FlaggedApi("android.companion.device_presence") public static final int DEVICE_EVENT_SELF_MANAGED_APPEARED = 4; // 0x4
-    field @FlaggedApi("android.companion.device_presence") public static final int DEVICE_EVENT_SELF_MANAGED_DISAPPEARED = 5; // 0x5
+    method @FlaggedApi("android.companion.device_presence") @MainThread public void onDevicePresenceEvent(@NonNull android.companion.DevicePresenceEvent);
     field public static final String SERVICE_INTERFACE = "android.companion.CompanionDeviceService";
   }
 
@@ -9744,6 +9741,38 @@
   public class DeviceNotAssociatedException extends java.lang.RuntimeException {
   }
 
+  @FlaggedApi("android.companion.device_presence") public final class DevicePresenceEvent implements android.os.Parcelable {
+    ctor public DevicePresenceEvent(int, int, @Nullable android.os.ParcelUuid);
+    method public int describeContents();
+    method public int getAssociationId();
+    method public int getEvent();
+    method @Nullable public android.os.ParcelUuid getUuid();
+    method public void writeToParcel(@NonNull android.os.Parcel, int);
+    field @NonNull public static final android.os.Parcelable.Creator<android.companion.DevicePresenceEvent> CREATOR;
+    field public static final int EVENT_BLE_APPEARED = 0; // 0x0
+    field public static final int EVENT_BLE_DISAPPEARED = 1; // 0x1
+    field public static final int EVENT_BT_CONNECTED = 2; // 0x2
+    field public static final int EVENT_BT_DISCONNECTED = 3; // 0x3
+    field public static final int EVENT_SELF_MANAGED_APPEARED = 4; // 0x4
+    field public static final int EVENT_SELF_MANAGED_DISAPPEARED = 5; // 0x5
+    field public static final int NO_ASSOCIATION = -1; // 0xffffffff
+  }
+
+  @FlaggedApi("android.companion.device_presence") public final class ObservingDevicePresenceRequest implements android.os.Parcelable {
+    method public int describeContents();
+    method public int getAssociationId();
+    method @Nullable public android.os.ParcelUuid getUuid();
+    method public void writeToParcel(@NonNull android.os.Parcel, int);
+    field @NonNull public static final android.os.Parcelable.Creator<android.companion.ObservingDevicePresenceRequest> CREATOR;
+  }
+
+  public static final class ObservingDevicePresenceRequest.Builder {
+    ctor public ObservingDevicePresenceRequest.Builder();
+    method @NonNull public android.companion.ObservingDevicePresenceRequest build();
+    method @NonNull public android.companion.ObservingDevicePresenceRequest.Builder setAssociationId(int);
+    method @NonNull @RequiresPermission(android.Manifest.permission.REQUEST_OBSERVE_DEVICE_UUID_PRESENCE) public android.companion.ObservingDevicePresenceRequest.Builder setUuid(@NonNull android.os.ParcelUuid);
+  }
+
   public final class WifiDeviceFilter implements android.companion.DeviceFilter<android.net.wifi.ScanResult> {
     method public int describeContents();
     method public void writeToParcel(@NonNull android.os.Parcel, int);
diff --git a/core/java/android/companion/CompanionDeviceManager.java b/core/java/android/companion/CompanionDeviceManager.java
index 672e3439..d743992 100644
--- a/core/java/android/companion/CompanionDeviceManager.java
+++ b/core/java/android/companion/CompanionDeviceManager.java
@@ -1038,6 +1038,7 @@
         }
     }
 
+    // TODO(b/315163162) Add @Deprecated keyword after 24Q2 cut.
     /**
      * Register to receive callbacks whenever the associated device comes in and out of range.
      *
@@ -1094,7 +1095,7 @@
                             callingUid, callingPid);
         }
     }
-
+    // TODO(b/315163162) Add @Deprecated keyword after 24Q2 cut.
     /**
      * Unregister for receiving callbacks whenever the associated device comes in and out of range.
      *
@@ -1137,6 +1138,64 @@
     }
 
     /**
+     * Register to receive callbacks whenever the associated device comes in and out of range.
+     *
+     * <p>The app doesn't need to remain running in order to receive its callbacks.</p>
+     *
+     * <p>Calling app must check for feature presence of
+     * {@link PackageManager#FEATURE_COMPANION_DEVICE_SETUP} before calling this API.</p>
+     *
+     * <p>For Bluetooth LE devices, this is based on scanning for device with the given address.
+     * The system will scan for the device when Bluetooth is ON or Bluetooth scanning is ON.</p>
+     *
+     * <p>For Bluetooth classic devices this is triggered when the device connects/disconnects.</p>
+     *
+     * <p>WiFi devices are not supported.</p>
+     *
+     * <p>If a Bluetooth LE device wants to use a rotating mac address, it is recommended to use
+     * Resolvable Private Address, and ensure the device is bonded to the phone so that android OS
+     * is able to resolve the address.</p>
+     *
+     * @param request A request for setting the types of device for observing device presence.
+     *
+     * @see ObservingDevicePresenceRequest.Builder
+     * @see CompanionDeviceService#onDevicePresenceEvent(DevicePresenceEvent)
+     */
+    @FlaggedApi(Flags.FLAG_DEVICE_PRESENCE)
+    @RequiresPermission(android.Manifest.permission.REQUEST_OBSERVE_COMPANION_DEVICE_PRESENCE)
+    public void startObservingDevicePresence(@NonNull ObservingDevicePresenceRequest request) {
+        Objects.requireNonNull(request, "request cannot be null");
+
+        try {
+            mService.startObservingDevicePresence(
+                    request, mContext.getOpPackageName(), mContext.getUserId());
+        } catch (RemoteException e) {
+            throw e.rethrowFromSystemServer();
+        }
+    }
+
+    /**
+     * Unregister for receiving callbacks whenever the associated device comes in and out of range.
+     *
+     * Calling app must check for feature presence of
+     * {@link PackageManager#FEATURE_COMPANION_DEVICE_SETUP} before calling this API.
+     *
+     * @param request A request for setting the types of device for observing device presence.
+     */
+    @FlaggedApi(Flags.FLAG_DEVICE_PRESENCE)
+    @RequiresPermission(android.Manifest.permission.REQUEST_OBSERVE_COMPANION_DEVICE_PRESENCE)
+    public void stopObservingDevicePresence(@NonNull ObservingDevicePresenceRequest request) {
+        Objects.requireNonNull(request, "request cannot be null");
+
+        try {
+            mService.stopObservingDevicePresence(
+                    request, mContext.getOpPackageName(), mContext.getUserId());
+        } catch (RemoteException e) {
+            throw e.rethrowFromSystemServer();
+        }
+    }
+
+    /**
      * Dispatch a message to system for processing. It should only be called by
      * {@link CompanionDeviceService#dispatchMessageToSystem(int, int, byte[])}
      *
diff --git a/core/java/android/companion/CompanionDeviceService.java b/core/java/android/companion/CompanionDeviceService.java
index 4d0267c..5ad2348 100644
--- a/core/java/android/companion/CompanionDeviceService.java
+++ b/core/java/android/companion/CompanionDeviceService.java
@@ -18,7 +18,6 @@
 package android.companion;
 
 import android.annotation.FlaggedApi;
-import android.annotation.IntDef;
 import android.annotation.MainThread;
 import android.annotation.NonNull;
 import android.annotation.Nullable;
@@ -33,8 +32,6 @@
 
 import java.io.InputStream;
 import java.io.OutputStream;
-import java.lang.annotation.Retention;
-import java.lang.annotation.RetentionPolicy;
 import java.util.Objects;
 import java.util.concurrent.Executor;
 
@@ -123,62 +120,6 @@
      */
     public static final String SERVICE_INTERFACE = "android.companion.CompanionDeviceService";
 
-    /** @hide */
-    @IntDef(prefix = {"DEVICE_EVENT"}, value = {
-            DEVICE_EVENT_BLE_APPEARED,
-            DEVICE_EVENT_BLE_DISAPPEARED,
-            DEVICE_EVENT_BT_CONNECTED,
-            DEVICE_EVENT_BT_DISCONNECTED,
-            DEVICE_EVENT_SELF_MANAGED_APPEARED,
-            DEVICE_EVENT_SELF_MANAGED_DISAPPEARED
-    })
-
-    @Retention(RetentionPolicy.SOURCE)
-    public @interface DeviceEvent {}
-
-    /**
-     * Companion app receives {@link #onDeviceEvent(AssociationInfo, int)} callback
-     * with this event if the device comes into BLE range.
-     */
-    @FlaggedApi(Flags.FLAG_DEVICE_PRESENCE)
-    public static final int DEVICE_EVENT_BLE_APPEARED = 0;
-
-    /**
-     * Companion app receives {@link #onDeviceEvent(AssociationInfo, int)} callback
-     * with this event if the device is no longer in BLE range.
-     */
-    @FlaggedApi(Flags.FLAG_DEVICE_PRESENCE)
-    public static final int DEVICE_EVENT_BLE_DISAPPEARED = 1;
-
-    /**
-     * Companion app receives {@link #onDeviceEvent(AssociationInfo, int)} callback
-     * with this event when the bluetooth device is connected.
-     */
-    @FlaggedApi(Flags.FLAG_DEVICE_PRESENCE)
-    public static final int DEVICE_EVENT_BT_CONNECTED = 2;
-
-    /**
-     * Companion app receives {@link #onDeviceEvent(AssociationInfo, int)} callback
-     * with this event if the bluetooth device is disconnected.
-     */
-    @FlaggedApi(Flags.FLAG_DEVICE_PRESENCE)
-    public static final int DEVICE_EVENT_BT_DISCONNECTED = 3;
-
-    /**
-     * A companion app for a self-managed device will receive the callback
-     * {@link #onDeviceEvent(AssociationInfo, int)} if it reports that a device has appeared on its
-     * own.
-     */
-    @FlaggedApi(Flags.FLAG_DEVICE_PRESENCE)
-    public static final int DEVICE_EVENT_SELF_MANAGED_APPEARED = 4;
-
-    /**
-     * A companion app for a self-managed device will receive the callback
-     * {@link #onDeviceEvent(AssociationInfo, int)} if it reports that a device has disappeared on
-     * its own.
-     */
-    @FlaggedApi(Flags.FLAG_DEVICE_PRESENCE)
-    public static final int DEVICE_EVENT_SELF_MANAGED_DISAPPEARED = 5;
 
     private final Stub mRemote = new Stub();
 
@@ -306,6 +247,7 @@
                 .detachSystemDataTransport(associationId);
     }
 
+    // TODO(b/315163162) Add @Deprecated keyword after 24Q2 cut.
     /**
      * Called by system whenever a device associated with this app is connected.
      *
@@ -318,6 +260,7 @@
         }
     }
 
+    // TODO(b/315163162) Add @Deprecated keyword after 24Q2 cut.
     /**
      * Called by system whenever a device associated with this app is disconnected.
      *
@@ -331,27 +274,13 @@
     }
 
     /**
-     *  Called by the system during device events.
+     * Called by the system during device events.
      *
-     *  <p>E.g. Event {@link #DEVICE_EVENT_BLE_APPEARED} will be called when the associated
-     *  companion device comes into BLE range.
-     *  <p>Event {@link #DEVICE_EVENT_BLE_DISAPPEARED} will be called when the associated
-     *  companion device is no longer in BLE range.
-     *  <p> Event {@link #DEVICE_EVENT_BT_CONNECTED} will be called when the associated
-     *  companion device is connected.
-     *  <p>Event {@link #DEVICE_EVENT_BT_DISCONNECTED} will be called when the associated
-     *  companion device is disconnected.
-     *  Note that app must receive {@link #DEVICE_EVENT_BLE_APPEARED} first before
-     *  {@link #DEVICE_EVENT_BLE_DISAPPEARED} and {@link #DEVICE_EVENT_BT_CONNECTED}
-     *  before {@link #DEVICE_EVENT_BT_DISCONNECTED}.
-     *
-     * @param associationInfo A record for the companion device.
-     * @param event Associated companion device's event.
+     * @see CompanionDeviceManager#startObservingDevicePresence(ObservingDevicePresenceRequest)
      */
     @FlaggedApi(Flags.FLAG_DEVICE_PRESENCE)
     @MainThread
-    public void onDeviceEvent(@NonNull AssociationInfo associationInfo,
-            @DeviceEvent int event) {
+    public void onDevicePresenceEvent(@NonNull DevicePresenceEvent event) {
         // Do nothing. Companion apps can override this function.
     }
 
@@ -390,9 +319,10 @@
         }
 
         @Override
-        public void onDeviceEvent(AssociationInfo associationInfo, int event) {
-            mMainHandler.postAtFrontOfQueue(
-                    () -> mService.onDeviceEvent(associationInfo, event));
+        public void onDevicePresenceEvent(DevicePresenceEvent event) {
+            if (Flags.devicePresence()) {
+                mMainHandler.postAtFrontOfQueue(() -> mService.onDevicePresenceEvent(event));
+            }
         }
     }
 }
diff --git a/core/java/android/companion/DevicePresenceEvent.aidl b/core/java/android/companion/DevicePresenceEvent.aidl
new file mode 100644
index 0000000..1521574
--- /dev/null
+++ b/core/java/android/companion/DevicePresenceEvent.aidl
@@ -0,0 +1,19 @@
+ /*
+  * Copyright (C) 2024 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.companion;
+
+ parcelable DevicePresenceEvent;
diff --git a/core/java/android/companion/DevicePresenceEvent.java b/core/java/android/companion/DevicePresenceEvent.java
new file mode 100644
index 0000000..30439a5
--- /dev/null
+++ b/core/java/android/companion/DevicePresenceEvent.java
@@ -0,0 +1,218 @@
+/*
+ * Copyright (C) 2024 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.companion;
+
+import android.annotation.FlaggedApi;
+import android.annotation.IntDef;
+import android.annotation.NonNull;
+import android.annotation.Nullable;
+import android.os.Parcel;
+import android.os.ParcelUuid;
+import android.os.Parcelable;
+
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.util.Objects;
+
+/**
+ * Event for observing device presence.
+ *
+ * @see CompanionDeviceManager#startObservingDevicePresence(ObservingDevicePresenceRequest)
+ * @see ObservingDevicePresenceRequest.Builder#setUuid(ParcelUuid)
+ * @see ObservingDevicePresenceRequest.Builder#setAssociationId(int)
+ */
+@FlaggedApi(Flags.FLAG_DEVICE_PRESENCE)
+public final class DevicePresenceEvent implements Parcelable {
+
+    /** @hide */
+    @IntDef(prefix = {"EVENT"}, value = {
+            EVENT_BLE_APPEARED,
+            EVENT_BLE_DISAPPEARED,
+            EVENT_BT_CONNECTED,
+            EVENT_BT_DISCONNECTED,
+            EVENT_SELF_MANAGED_APPEARED,
+            EVENT_SELF_MANAGED_DISAPPEARED
+    })
+
+    @Retention(RetentionPolicy.SOURCE)
+    public @interface Event {}
+
+    /**
+     * Indicate observing device presence base on the ParcelUuid but not association id.
+     */
+    public static final int NO_ASSOCIATION = -1;
+
+    /**
+     * Companion app receives
+     * {@link CompanionDeviceService#onDevicePresenceEvent(DevicePresenceEvent)} callback
+     * with this event if the device comes into BLE range.
+     */
+    public static final int EVENT_BLE_APPEARED = 0;
+
+    /**
+     * Companion app receives
+     * {@link CompanionDeviceService#onDevicePresenceEvent(DevicePresenceEvent)} callback
+     * with this event if the device is no longer in BLE range.
+     */
+    public static final int EVENT_BLE_DISAPPEARED = 1;
+
+    /**
+     * Companion app receives
+     * {@link CompanionDeviceService#onDevicePresenceEvent(DevicePresenceEvent)} callback
+     * with this event when the bluetooth device is connected.
+     */
+    public static final int EVENT_BT_CONNECTED = 2;
+
+    /**
+     * Companion app receives
+     * {@link CompanionDeviceService#onDevicePresenceEvent(DevicePresenceEvent)} callback
+     * with this event if the bluetooth device is disconnected.
+     */
+    public static final int EVENT_BT_DISCONNECTED = 3;
+
+    /**
+     * A companion app for a self-managed device will receive the callback
+     * {@link CompanionDeviceService#onDevicePresenceEvent(DevicePresenceEvent)}
+     * if it reports that a device has appeared on its
+     * own.
+     */
+    public static final int EVENT_SELF_MANAGED_APPEARED = 4;
+
+    /**
+     * A companion app for a self-managed device will receive the callback
+     * {@link CompanionDeviceService#onDevicePresenceEvent(DevicePresenceEvent)} if it reports
+     * that a device has disappeared on its own.
+     */
+    public static final int EVENT_SELF_MANAGED_DISAPPEARED = 5;
+    private final int mAssociationId;
+    private final int mEvent;
+    @Nullable
+    private final ParcelUuid mUuid;
+
+    private static final int PARCEL_UUID_NULL = 0;
+
+    private static final int PARCEL_UUID_NOT_NULL = 1;
+
+    /**
+     * Create a new DevicePresenceEvent.
+     */
+    public DevicePresenceEvent(
+            int associationId, @Event int event, @Nullable ParcelUuid uuid) {
+        mAssociationId = associationId;
+        mEvent = event;
+        mUuid = uuid;
+    }
+
+    /**
+     * @return The association id has been used to observe device presence.
+     *
+     * Caller will receive the valid association id if only if using
+     * {@link ObservingDevicePresenceRequest.Builder#setAssociationId(int)}, otherwise
+     * return {@link #NO_ASSOCIATION}.
+     *
+     * @see ObservingDevicePresenceRequest.Builder#setAssociationId(int)
+     */
+    public int getAssociationId() {
+        return mAssociationId;
+    }
+
+    /**
+     * @return Associated companion device's event.
+     */
+    public int getEvent() {
+        return mEvent;
+    }
+
+    /**
+     * @return The ParcelUuid has been used to observe device presence.
+     *
+     * Caller will receive the ParcelUuid if only if using
+     * {@link ObservingDevicePresenceRequest.Builder#setUuid(ParcelUuid)}, otherwise return null.
+     *
+     * @see ObservingDevicePresenceRequest.Builder#setUuid(ParcelUuid)
+     */
+
+    @Nullable
+    public ParcelUuid getUuid() {
+        return mUuid;
+    }
+
+    @Override
+    public int describeContents() {
+        return 0;
+    }
+
+    @Override
+    public void writeToParcel(@NonNull Parcel dest, int flags) {
+        dest.writeInt(mAssociationId);
+        dest.writeInt(mEvent);
+        if (mUuid == null) {
+            // Write 0 to the parcel to indicate the ParcelUuid is null.
+            dest.writeInt(PARCEL_UUID_NULL);
+        } else {
+            dest.writeInt(PARCEL_UUID_NOT_NULL);
+            mUuid.writeToParcel(dest, flags);
+        }
+    }
+
+    @Override
+    public boolean equals(@Nullable Object o) {
+        if (this == o) return true;
+        if (!(o instanceof DevicePresenceEvent that)) return false;
+
+        return Objects.equals(mUuid, that.mUuid)
+                && mAssociationId == that.mAssociationId
+                && mEvent == that.mEvent;
+    }
+
+    @Override
+    public String toString() {
+        return "ObservingDevicePresenceResult { "
+                + "Association Id= " + mAssociationId + ","
+                + "ParcelUuid= " + mUuid + ","
+                + "Event= " + mEvent + "}";
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(mAssociationId, mEvent, mUuid);
+    }
+
+    @NonNull
+    public static final Parcelable.Creator<DevicePresenceEvent> CREATOR =
+            new Parcelable.Creator<DevicePresenceEvent>() {
+                @Override
+                public DevicePresenceEvent[] newArray(int size) {
+                    return new DevicePresenceEvent[size];
+                }
+
+                @Override
+                public DevicePresenceEvent createFromParcel(@NonNull Parcel in) {
+                    return new DevicePresenceEvent(in);
+                }
+            };
+
+    private DevicePresenceEvent(@NonNull Parcel in) {
+        mAssociationId = in.readInt();
+        mEvent = in.readInt();
+        if (in.readInt() == PARCEL_UUID_NULL) {
+            mUuid = null;
+        } else {
+            mUuid = ParcelUuid.CREATOR.createFromParcel(in);
+        }
+    }
+}
diff --git a/core/java/android/companion/ICompanionDeviceManager.aidl b/core/java/android/companion/ICompanionDeviceManager.aidl
index 22689f3..57d59e5 100644
--- a/core/java/android/companion/ICompanionDeviceManager.aidl
+++ b/core/java/android/companion/ICompanionDeviceManager.aidl
@@ -24,8 +24,11 @@
 import android.companion.ISystemDataTransferCallback;
 import android.companion.AssociationInfo;
 import android.companion.AssociationRequest;
+import android.companion.ObservingDevicePresenceRequest;
 import android.companion.datatransfer.PermissionSyncRequest;
 import android.content.ComponentName;
+import android.os.ParcelUuid;
+
 
 /**
  * Interface for communication with the core companion device manager service.
@@ -132,4 +135,10 @@
     byte[] getBackupPayload(int userId);
 
     void applyRestoredPayload(in byte[] payload, int userId);
+
+    @EnforcePermission("REQUEST_OBSERVE_COMPANION_DEVICE_PRESENCE")
+    void startObservingDevicePresence(in ObservingDevicePresenceRequest request, in String packageName, int userId);
+
+    @EnforcePermission("REQUEST_OBSERVE_COMPANION_DEVICE_PRESENCE")
+    void stopObservingDevicePresence(in ObservingDevicePresenceRequest request, in String packageName, int userId);
 }
diff --git a/core/java/android/companion/ICompanionDeviceService.aidl b/core/java/android/companion/ICompanionDeviceService.aidl
index 2a311bf..f5401d2 100644
--- a/core/java/android/companion/ICompanionDeviceService.aidl
+++ b/core/java/android/companion/ICompanionDeviceService.aidl
@@ -17,10 +17,12 @@
 package android.companion;
 
 import android.companion.AssociationInfo;
+import android.companion.DevicePresenceEvent;
+import android.os.ParcelUuid;
 
 /** @hide */
 oneway interface ICompanionDeviceService {
     void onDeviceAppeared(in AssociationInfo associationInfo);
     void onDeviceDisappeared(in AssociationInfo associationInfo);
-    void onDeviceEvent(in AssociationInfo associationInfo, int state);
+    void onDevicePresenceEvent(in DevicePresenceEvent event);
 }
diff --git a/core/java/android/companion/ObservingDevicePresenceRequest.aidl b/core/java/android/companion/ObservingDevicePresenceRequest.aidl
new file mode 100644
index 0000000..fed0607
--- /dev/null
+++ b/core/java/android/companion/ObservingDevicePresenceRequest.aidl
@@ -0,0 +1,19 @@
+ /*
+  * Copyright (C) 2024 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.companion;
+
+ parcelable ObservingDevicePresenceRequest;
\ No newline at end of file
diff --git a/core/java/android/companion/ObservingDevicePresenceRequest.java b/core/java/android/companion/ObservingDevicePresenceRequest.java
new file mode 100644
index 0000000..f1d594e
--- /dev/null
+++ b/core/java/android/companion/ObservingDevicePresenceRequest.java
@@ -0,0 +1,208 @@
+/*
+ * Copyright (C) 2024 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.companion;
+
+import android.annotation.FlaggedApi;
+import android.annotation.NonNull;
+import android.annotation.Nullable;
+import android.annotation.RequiresPermission;
+import android.os.Parcel;
+import android.os.ParcelUuid;
+import android.os.Parcelable;
+import android.provider.OneTimeUseBuilder;
+
+import java.util.Objects;
+
+/**
+ * A request for setting the types of device for observing device presence.
+ *
+ * <p>Only supports association id or ParcelUuid and calling app must declare uses-permission
+ * {@link android.Manifest.permission#REQUEST_OBSERVE_DEVICE_UUID_PRESENCE} if using
+ * {@link Builder#setUuid(ParcelUuid)}.</p>
+ *
+ * Calling apps must use either ObservingDevicePresenceRequest.Builder#setUuid(ParcelUuid) or
+ * ObservingDevicePresenceRequest.Builder#setAssociationId(int), but not both.
+ *
+ * @see Builder#setUuid(ParcelUuid)
+ * @see Builder#setAssociationId(int)
+ * @see CompanionDeviceManager#startObservingDevicePresence(ObservingDevicePresenceRequest)
+ */
+@FlaggedApi(Flags.FLAG_DEVICE_PRESENCE)
+public final class ObservingDevicePresenceRequest implements Parcelable {
+    private final int mAssociationId;
+    @Nullable private final ParcelUuid mUuid;
+
+    private static final int PARCEL_UUID_NULL = 0;
+
+    private static final int PARCEL_UUID_NOT_NULL = 1;
+
+    private ObservingDevicePresenceRequest(int associationId, ParcelUuid uuid) {
+        mAssociationId = associationId;
+        mUuid = uuid;
+    }
+
+    private ObservingDevicePresenceRequest(@NonNull Parcel in) {
+        mAssociationId = in.readInt();
+        if (in.readInt() == PARCEL_UUID_NULL) {
+            mUuid = null;
+        } else {
+            mUuid = ParcelUuid.CREATOR.createFromParcel(in);
+        }
+    }
+
+    /**
+     * @return the association id for observing device presence. It will return
+     * {@link DevicePresenceEvent#NO_ASSOCIATION} if using
+     * {@link Builder#setUuid(ParcelUuid)}.
+     */
+    public int getAssociationId() {
+        return mAssociationId;
+    }
+
+    /**
+     * @return the ParcelUuid for observing device presence.
+     */
+    @Nullable
+    public ParcelUuid getUuid() {
+        return mUuid;
+    }
+
+    @Override
+    public void writeToParcel(@NonNull Parcel dest, int flags) {
+        dest.writeInt(mAssociationId);
+        if (mUuid == null) {
+            // Write 0 to the parcel to indicate the ParcelUuid is null.
+            dest.writeInt(PARCEL_UUID_NULL);
+        } else {
+            dest.writeInt(PARCEL_UUID_NOT_NULL);
+            mUuid.writeToParcel(dest, flags);
+        }
+
+    }
+
+    @Override
+    public int describeContents() {
+        return 0;
+    }
+
+    @NonNull
+    public static final Parcelable.Creator<ObservingDevicePresenceRequest> CREATOR =
+            new Parcelable.Creator<ObservingDevicePresenceRequest>() {
+                @Override
+                public ObservingDevicePresenceRequest[] newArray(int size) {
+                    return new ObservingDevicePresenceRequest[size];
+                }
+
+                @Override
+                public ObservingDevicePresenceRequest createFromParcel(@NonNull Parcel in) {
+                    return new ObservingDevicePresenceRequest(in);
+                }
+            };
+
+    @Override
+    public String toString() {
+        return "ObservingDevicePresenceRequest { "
+                + "Association Id= " + mAssociationId + ","
+                + "ParcelUuid= " + mUuid + "}";
+    }
+
+    @Override
+    public boolean equals(@Nullable Object o) {
+        if (this == o) return true;
+        if (!(o instanceof ObservingDevicePresenceRequest that)) return false;
+
+        return Objects.equals(mUuid, that.mUuid) && mAssociationId == that.mAssociationId;
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(mAssociationId, mUuid);
+    }
+
+    /**
+     * A builder for {@link ObservingDevicePresenceRequest}
+     */
+    public static final class Builder extends OneTimeUseBuilder<ObservingDevicePresenceRequest> {
+        // Initial the association id to {@link DevicePresenceEvent.NO_ASSOCIATION}
+        // to indicate the value is not set yet.
+        private int mAssociationId = DevicePresenceEvent.NO_ASSOCIATION;
+        private ParcelUuid mUuid;
+
+        public Builder() {}
+
+        /**
+         * Set the association id to be observed for device presence.
+         *
+         * <p>The provided device must be {@link CompanionDeviceManager#associate associated}
+         * with the calling app before calling this method if using this API.
+         *
+         * Caller must implement a single {@link CompanionDeviceService} which will be bound to and
+         * receive callbacks to
+         * {@link CompanionDeviceService#onDevicePresenceEvent(DevicePresenceEvent)}.</p>
+         *
+         * <p>Calling apps must use either {@link #setUuid(ParcelUuid)}
+         * or this API, but not both.</p>
+         *
+         * @param associationId The association id for observing device presence.
+         */
+        @NonNull
+        public Builder setAssociationId(int associationId) {
+            checkNotUsed();
+            this.mAssociationId = associationId;
+            return this;
+        }
+
+        /**
+         * Set the ParcelUuid to be observed for device presence.
+         *
+         * <p>It does not require to create the association before calling this API.
+         * This only supports classic Bluetooth scan and caller must implement
+         * a single {@link CompanionDeviceService} which will be bound to and receive callbacks to
+         * {@link CompanionDeviceService#onDevicePresenceEvent(DevicePresenceEvent)}.</p>
+         *
+         * <p>The Uuid should be matching one of the ParcelUuid form
+         * {@link android.bluetooth.BluetoothDevice#getUuids()}</p>
+         *
+         * <p>Calling apps must use either this API or {@link #setAssociationId(int)},
+         * but not both.</p>
+         *
+         * @param uuid The ParcelUuid for observing device presence.
+         */
+        @NonNull
+        @RequiresPermission(android.Manifest.permission.REQUEST_OBSERVE_DEVICE_UUID_PRESENCE)
+        public Builder setUuid(@NonNull ParcelUuid uuid) {
+            checkNotUsed();
+            this.mUuid = uuid;
+            return this;
+        }
+
+        @NonNull
+        @Override
+        public ObservingDevicePresenceRequest build() {
+            markUsed();
+            if (mUuid != null && mAssociationId != DevicePresenceEvent.NO_ASSOCIATION) {
+                throw new IllegalStateException("Cannot observe device presence based on "
+                        + "both ParcelUuid and association ID. Choose one or the other.");
+            } else if (mUuid == null && mAssociationId <= 0) {
+                throw new IllegalStateException("Must provide either a ParcelUuid or "
+                        + "a valid association ID to observe device presence.");
+            }
+
+            return new ObservingDevicePresenceRequest(mAssociationId, mUuid);
+        }
+    }
+}
diff --git a/core/java/android/companion/flags.aconfig b/core/java/android/companion/flags.aconfig
index 9e410b8..d634b64 100644
--- a/core/java/android/companion/flags.aconfig
+++ b/core/java/android/companion/flags.aconfig
@@ -33,4 +33,4 @@
     namespace: "companion"
     description: "Expose perm sync user consent API"
     bug: "309528663"
-}
\ No newline at end of file
+}
diff --git a/core/res/AndroidManifest.xml b/core/res/AndroidManifest.xml
index fea1fc0..f9731d4 100644
--- a/core/res/AndroidManifest.xml
+++ b/core/res/AndroidManifest.xml
@@ -5737,6 +5737,14 @@
                 android:description="@string/permdesc_observeCompanionDevicePresence"
                 android:protectionLevel="normal" />
 
+    <!-- Allows an application to subscribe to notifications about the nearby devices' presence
+         status change base on the UUIDs.
+         <p>Not for use by third-party applications.</p>
+         @FlaggedApi("android.companion.flags.device_presence")
+    -->
+    <permission android:name="android.permission.REQUEST_OBSERVE_DEVICE_UUID_PRESENCE"
+                android:protectionLevel="signature|privileged" />
+
     <!-- Allows an application to deliver companion messages to system
          -->
     <permission android:name="android.permission.DELIVER_COMPANION_MESSAGES"
diff --git a/data/etc/privapp-permissions-platform.xml b/data/etc/privapp-permissions-platform.xml
index 294b8ae..97b1ec7 100644
--- a/data/etc/privapp-permissions-platform.xml
+++ b/data/etc/privapp-permissions-platform.xml
@@ -421,6 +421,8 @@
         <permission name="android.permission.REQUEST_COMPANION_PROFILE_NEARBY_DEVICE_STREAMING" />
         <permission name="android.permission.REQUEST_COMPANION_PROFILE_COMPUTER" />
         <permission name="android.permission.REQUEST_COMPANION_SELF_MANAGED" />
+        <permission name="android.permission.REQUEST_OBSERVE_DEVICE_UUID_PRESENCE" />
+
         <!-- Permission required for testing registering pull atom callbacks. -->
         <permission name="android.permission.REGISTER_STATS_PULL_ATOM"/>
         <!-- Permission required for testing system audio effect APIs. -->
diff --git a/packages/Shell/AndroidManifest.xml b/packages/Shell/AndroidManifest.xml
index cc63996..d384542 100644
--- a/packages/Shell/AndroidManifest.xml
+++ b/packages/Shell/AndroidManifest.xml
@@ -343,6 +343,7 @@
     <uses-permission android:name="android.permission.REQUEST_COMPANION_PROFILE_GLASSES" />
     <uses-permission android:name="android.permission.REQUEST_COMPANION_SELF_MANAGED" />
     <uses-permission android:name="android.permission.USE_COMPANION_TRANSPORTS" />
+    <uses-permission android:name="android.permission.REQUEST_OBSERVE_DEVICE_UUID_PRESENCE" />
 
     <uses-permission android:name="android.permission.MANAGE_APPOPS" />
     <uses-permission android:name="android.permission.WATCH_APPOPS" />
diff --git a/services/companion/java/com/android/server/companion/CompanionApplicationController.java b/services/companion/java/com/android/server/companion/CompanionApplicationController.java
index c2d2468..586aa8a 100644
--- a/services/companion/java/com/android/server/companion/CompanionApplicationController.java
+++ b/services/companion/java/com/android/server/companion/CompanionApplicationController.java
@@ -22,9 +22,11 @@
 import android.annotation.UserIdInt;
 import android.companion.AssociationInfo;
 import android.companion.CompanionDeviceService;
+import android.companion.DevicePresenceEvent;
 import android.content.ComponentName;
 import android.content.Context;
 import android.os.Handler;
+import android.os.ParcelUuid;
 import android.util.Log;
 import android.util.Slog;
 import android.util.SparseArray;
@@ -46,7 +48,8 @@
  * the services, maintaining the connection (the binding), and invoking callback methods such as
  * {@link CompanionDeviceService#onDeviceAppeared(AssociationInfo)},
  * {@link CompanionDeviceService#onDeviceDisappeared(AssociationInfo)} and
- * {@link CompanionDeviceService#onDeviceEvent(AssociationInfo, int)} in the application process.
+ * {@link CompanionDeviceService#onDevicePresenceEvent(DevicePresenceEvent)} in the
+ * application process.
  *
  * <p>
  * The following is the list of the APIs provided by {@link CompanionApplicationController} (to be
@@ -54,7 +57,7 @@
  * <ul>
  * <li> {@link #bindCompanionApplication(int, String, boolean)}
  * <li> {@link #unbindCompanionApplication(int, String)}
- * <li> {@link #notifyCompanionApplicationDeviceEvent(AssociationInfo, int)} (AssociationInfo, int)}
+ * <li> {@link #notifyCompanionApplicationDevicePresenceEvent(AssociationInfo, int)}
  * <li> {@link #isCompanionApplicationBound(int, String)}
  * <li> {@link #isRebindingCompanionApplicationScheduled(int, String)}
  * </ul>
@@ -72,6 +75,7 @@
 
     private final @NonNull Context mContext;
     private final @NonNull AssociationStore mAssociationStore;
+    private final @NonNull ObservableUuidStore mObservableUuidStore;
     private final @NonNull CompanionDevicePresenceMonitor mDevicePresenceMonitor;
     private final @NonNull CompanionServicesRegister mCompanionServicesRegister;
 
@@ -82,9 +86,11 @@
     private final @NonNull AndroidPackageMap<Boolean> mScheduledForRebindingCompanionApplications;
 
     CompanionApplicationController(Context context, AssociationStore associationStore,
+            ObservableUuidStore observableUuidStore,
             CompanionDevicePresenceMonitor companionDevicePresenceMonitor) {
         mContext = context;
         mAssociationStore = associationStore;
+        mObservableUuidStore =  observableUuidStore;
         mDevicePresenceMonitor = companionDevicePresenceMonitor;
         mCompanionServicesRegister = new CompanionServicesRegister();
         mBoundCompanionApplications = new AndroidPackageMap<>();
@@ -281,25 +287,50 @@
         primaryServiceConnector.postOnDeviceDisappeared(association);
     }
 
-    void notifyCompanionApplicationDeviceEvent(AssociationInfo association, int event) {
+    void notifyCompanionApplicationDevicePresenceEvent(AssociationInfo association, int event) {
         final int userId = association.getUserId();
         final String packageName = association.getPackageName();
         final CompanionDeviceServiceConnector primaryServiceConnector =
                 getPrimaryServiceConnector(userId, packageName);
+        final DevicePresenceEvent devicePresenceEvent =
+                new DevicePresenceEvent(association.getId(), event, null);
 
         if (primaryServiceConnector == null) {
-            Slog.e(TAG, "notifyCompanionApplicationDeviceEvent(): "
+            Slog.e(TAG, "notifyCompanionApplicationDevicePresenceEvent(): "
                         + "u" + userId + "/" + packageName
                         + " event=[ " + event  + " ] is NOT bound.");
             Slog.e(TAG, "Stacktrace", new Throwable());
             return;
         }
 
-        Slog.i(TAG, "Calling onDeviceEvent() to userId=[" + userId + "] package=["
+        Slog.i(TAG, "Calling onDevicePresenceEvent() to userId=[" + userId + "] package=["
                 + packageName + "] associationId=[" + association.getId()
-                + "] state=[" + event + "]");
+                + "] event=[" + event + "]");
 
-        primaryServiceConnector.postOnDeviceEvent(association, event);
+        primaryServiceConnector.postOnDevicePresenceEvent(devicePresenceEvent);
+    }
+
+    void notifyApplicationDevicePresenceEvent(ObservableUuid uuid, int event) {
+        final int userId = uuid.getUserId();
+        final ParcelUuid parcelUuid = uuid.getUuid();
+        final String packageName = uuid.getPackageName();
+        final CompanionDeviceServiceConnector primaryServiceConnector =
+                getPrimaryServiceConnector(userId, packageName);
+        final DevicePresenceEvent devicePresenceEvent =
+                new DevicePresenceEvent(DevicePresenceEvent.NO_ASSOCIATION, event, parcelUuid);
+
+        if (primaryServiceConnector == null) {
+            Slog.e(TAG, "notifyApplicationDevicePresenceChanged(): "
+                    + "u" + userId + "/" + packageName
+                    + " event=[ " + event  + " ] is NOT bound.");
+            Slog.e(TAG, "Stacktrace", new Throwable());
+            return;
+        }
+
+        Slog.i(TAG, "Calling onDevicePresenceEvent() to userId=[" + userId + "] package=["
+                + packageName + "]" + "event= [" + event + "]");
+
+        primaryServiceConnector.postOnDevicePresenceEvent(devicePresenceEvent);
     }
 
     void dump(@NonNull PrintWriter out) {
@@ -364,6 +395,9 @@
         // Make sure to clean up the state for all the associations
         // that associate with this package.
         boolean shouldScheduleRebind = false;
+        boolean shouldScheduleRebindForUuid = false;
+        final List<ObservableUuid> uuids =
+                mObservableUuidStore.getObservableUuidsForPackage(userId, packageName);
 
         for (AssociationInfo ai :
                 mAssociationStore.getAssociationsForPackage(userId, packageName)) {
@@ -385,7 +419,14 @@
             }
         }
 
-        return stillAssociated && shouldScheduleRebind;
+        for (ObservableUuid uuid : uuids) {
+            if (mDevicePresenceMonitor.isDeviceUuidPresent(uuid.getUuid())) {
+                shouldScheduleRebindForUuid = true;
+                break;
+            }
+        }
+
+        return (stillAssociated && shouldScheduleRebind) || shouldScheduleRebindForUuid;
     }
 
     private class CompanionServicesRegister extends PerUser<Map<String, List<ComponentName>>> {
diff --git a/services/companion/java/com/android/server/companion/CompanionDeviceManagerService.java b/services/companion/java/com/android/server/companion/CompanionDeviceManagerService.java
index 84e1d90..2e01ced 100644
--- a/services/companion/java/com/android/server/companion/CompanionDeviceManagerService.java
+++ b/services/companion/java/com/android/server/companion/CompanionDeviceManagerService.java
@@ -20,17 +20,17 @@
 import static android.Manifest.permission.ASSOCIATE_COMPANION_DEVICES;
 import static android.Manifest.permission.DELIVER_COMPANION_MESSAGES;
 import static android.Manifest.permission.MANAGE_COMPANION_DEVICES;
-import static android.Manifest.permission.REQUEST_OBSERVE_COMPANION_DEVICE_PRESENCE;
 import static android.Manifest.permission.REQUEST_COMPANION_PROFILE_AUTOMOTIVE_PROJECTION;
+import static android.Manifest.permission.REQUEST_OBSERVE_COMPANION_DEVICE_PRESENCE;
 import static android.Manifest.permission.USE_COMPANION_TRANSPORTS;
 import static android.app.ActivityManager.RunningAppProcessInfo.IMPORTANCE_VISIBLE;
 import static android.companion.AssociationRequest.DEVICE_PROFILE_AUTOMOTIVE_PROJECTION;
-import static android.companion.CompanionDeviceService.DEVICE_EVENT_BLE_APPEARED;
-import static android.companion.CompanionDeviceService.DEVICE_EVENT_BLE_DISAPPEARED;
-import static android.companion.CompanionDeviceService.DEVICE_EVENT_BT_CONNECTED;
-import static android.companion.CompanionDeviceService.DEVICE_EVENT_BT_DISCONNECTED;
-import static android.companion.CompanionDeviceService.DEVICE_EVENT_SELF_MANAGED_APPEARED;
-import static android.companion.CompanionDeviceService.DEVICE_EVENT_SELF_MANAGED_DISAPPEARED;
+import static android.companion.DevicePresenceEvent.EVENT_BLE_APPEARED;
+import static android.companion.DevicePresenceEvent.EVENT_BLE_DISAPPEARED;
+import static android.companion.DevicePresenceEvent.EVENT_BT_CONNECTED;
+import static android.companion.DevicePresenceEvent.EVENT_BT_DISCONNECTED;
+import static android.companion.DevicePresenceEvent.EVENT_SELF_MANAGED_APPEARED;
+import static android.companion.DevicePresenceEvent.EVENT_SELF_MANAGED_DISAPPEARED;
 import static android.content.pm.PackageManager.CERT_INPUT_SHA256;
 import static android.content.pm.PackageManager.PERMISSION_GRANTED;
 import static android.os.Process.SYSTEM_UID;
@@ -45,6 +45,7 @@
 import static com.android.server.companion.PackageUtils.getPackageInfo;
 import static com.android.server.companion.PermissionsUtils.checkCallerCanManageCompanionDevice;
 import static com.android.server.companion.PermissionsUtils.enforceCallerCanManageAssociationsForPackage;
+import static com.android.server.companion.PermissionsUtils.enforceCallerCanObservingDevicePresenceByUuid;
 import static com.android.server.companion.PermissionsUtils.enforceCallerIsSystemOr;
 import static com.android.server.companion.PermissionsUtils.enforceCallerIsSystemOrCanInteractWithUserId;
 import static com.android.server.companion.PermissionsUtils.sanitizeWithCallerChecks;
@@ -75,6 +76,7 @@
 import android.companion.IOnMessageReceivedListener;
 import android.companion.IOnTransportsChangedListener;
 import android.companion.ISystemDataTransferCallback;
+import android.companion.ObservingDevicePresenceRequest;
 import android.companion.datatransfer.PermissionSyncRequest;
 import android.content.ComponentName;
 import android.content.Context;
@@ -92,6 +94,7 @@
 import android.os.Message;
 import android.os.Parcel;
 import android.os.ParcelFileDescriptor;
+import android.os.ParcelUuid;
 import android.os.PowerManagerInternal;
 import android.os.PowerWhitelistManager;
 import android.os.RemoteCallbackList;
@@ -132,6 +135,7 @@
 import java.io.FileDescriptor;
 import java.io.PrintWriter;
 import java.util.ArrayList;
+import java.util.Arrays;
 import java.util.Collection;
 import java.util.Collections;
 import java.util.HashMap;
@@ -221,6 +225,8 @@
 
     private CrossDeviceSyncController mCrossDeviceSyncController;
 
+    private ObservableUuidStore mObservableUuidStore;
+
     public CompanionDeviceManagerService(Context context) {
         super(context);
 
@@ -240,6 +246,7 @@
         mOnPackageVisibilityChangeListener =
                 new OnPackageVisibilityChangeListener(mActivityManager);
         mPowerManagerInternal = LocalServices.getService(PowerManagerInternal.class);
+        mObservableUuidStore = new ObservableUuidStore();
     }
 
     @Override
@@ -254,13 +261,16 @@
                 mSystemDataTransferRequestStore, mAssociationRequestsProcessor);
 
         loadAssociationsFromDisk();
+
+        mObservableUuidStore.getObservableUuidsForUser(getContext().getUserId());
+
         mAssociationStore.registerListener(mAssociationStoreChangeListener);
 
         mDevicePresenceMonitor = new CompanionDevicePresenceMonitor(mUserManager,
-                mAssociationStore, mDevicePresenceCallback);
+                mAssociationStore, mObservableUuidStore, mDevicePresenceCallback);
 
         mCompanionAppController = new CompanionApplicationController(
-                context, mAssociationStore, mDevicePresenceMonitor);
+                context, mAssociationStore, mObservableUuidStore, mDevicePresenceMonitor);
         mTransportManager = new CompanionTransportManager(context, mAssociationStore);
         mSystemDataTransferProcessor = new SystemDataTransferProcessor(this,
                 mPackageManagerInternal, mAssociationStore,
@@ -352,13 +362,29 @@
         final int userId = user.getUserIdentifier();
         final Set<BluetoothDevice> blueToothDevices =
                 mDevicePresenceMonitor.getPendingConnectedDevices().get(userId);
+
+        final List<ObservableUuid> observableUuids =
+                mObservableUuidStore.getObservableUuidsForUser(userId);
+
         if (blueToothDevices != null) {
             for (BluetoothDevice bluetoothDevice : blueToothDevices) {
+                final List<ParcelUuid> deviceUuids = bluetoothDevice.getUuids() == null
+                        ? Collections.emptyList() : Arrays.asList(bluetoothDevice.getUuids());
+
                 for (AssociationInfo ai:
                         mAssociationStore.getAssociationsByAddress(bluetoothDevice.getAddress())) {
                     Slog.i(TAG, "onUserUnlocked, device id( " + ai.getId() + " ) is connected");
                     mDevicePresenceMonitor.onBluetoothCompanionDeviceConnected(ai.getId());
                 }
+
+                for (ObservableUuid observableUuid : observableUuids) {
+                    if (deviceUuids.contains(observableUuid.getUuid())) {
+                        Slog.i(TAG, "onUserUnlocked, UUID( "
+                                + observableUuid.getUuid() + " ) is connected");
+                        mDevicePresenceMonitor.onDevicePresenceEventByUuid(
+                                observableUuid, EVENT_BT_CONNECTED);
+                    }
+                }
             }
         }
     }
@@ -423,31 +449,31 @@
         }
     }
 
-    private void onDeviceEventInternal(int associationId, int event) {
-        Slog.i(TAG, "onDeviceEventInternal() id=" + associationId + " event= " + event);
+    private void onDevicePresenceEventInternal(int associationId, int event) {
+        Slog.i(TAG, "onDevicePresenceEventInternal() id=" + associationId + " event= " + event);
         final AssociationInfo association = mAssociationStore.getAssociationById(associationId);
         final String packageName = association.getPackageName();
         final int userId = association.getUserId();
         switch (event) {
-            case DEVICE_EVENT_BLE_APPEARED:
-            case DEVICE_EVENT_BT_CONNECTED:
-            case DEVICE_EVENT_SELF_MANAGED_APPEARED:
+            case EVENT_BLE_APPEARED:
+            case EVENT_BT_CONNECTED:
+            case EVENT_SELF_MANAGED_APPEARED:
                 if (!association.shouldBindWhenPresent()) return;
 
                 bindApplicationIfNeeded(association);
 
-                mCompanionAppController.notifyCompanionApplicationDeviceEvent(
+                mCompanionAppController.notifyCompanionApplicationDevicePresenceEvent(
                         association, event);
                 break;
-            case DEVICE_EVENT_BLE_DISAPPEARED:
-            case DEVICE_EVENT_BT_DISCONNECTED:
-            case DEVICE_EVENT_SELF_MANAGED_DISAPPEARED:
+            case EVENT_BLE_DISAPPEARED:
+            case EVENT_BT_DISCONNECTED:
+            case EVENT_SELF_MANAGED_DISAPPEARED:
                 if (!mCompanionAppController.isCompanionApplicationBound(userId, packageName)) {
                     if (DEBUG) Log.w(TAG, "u" + userId + "\\" + packageName + " is NOT bound");
                     return;
                 }
                 if (association.shouldBindWhenPresent()) {
-                    mCompanionAppController.notifyCompanionApplicationDeviceEvent(
+                    mCompanionAppController.notifyCompanionApplicationDevicePresenceEvent(
                             association, event);
                 }
                 // Check if there are other devices associated to the app that are present.
@@ -460,6 +486,45 @@
         }
     }
 
+    private void onDevicePresenceEventByUuidInternal(ObservableUuid uuid, int event) {
+        Slog.i(TAG, "onDevicePresenceEventByUuidInternal() id=" + uuid.getUuid()
+                + "for package=" + uuid.getPackageName() + " event=" + event);
+        final String packageName = uuid.getPackageName();
+        final int userId = uuid.getUserId();
+
+        switch(event) {
+            case EVENT_BT_CONNECTED:
+                if (!mCompanionAppController.isCompanionApplicationBound(userId, packageName)) {
+                    mCompanionAppController.bindCompanionApplication(
+                            userId, packageName, /*bindImportant*/ false);
+
+                } else if (DEBUG) {
+                    Log.i(TAG, "u" + userId + "\\" + packageName + " is already bound");
+                }
+
+                mCompanionAppController.notifyApplicationDevicePresenceEvent(uuid, event);
+
+                break;
+            case EVENT_BT_DISCONNECTED:
+                if (!mCompanionAppController.isCompanionApplicationBound(userId, packageName)) {
+                    if (DEBUG) Log.w(TAG, "u" + userId + "\\" + packageName + " is NOT bound");
+                    return;
+                }
+
+                mCompanionAppController.notifyApplicationDevicePresenceEvent(uuid, event);
+                // Check if there are other devices associated to the app or the UUID to be
+                // observed are present.
+                if (shouldBindPackage(userId, packageName)) return;
+
+                mCompanionAppController.unbindCompanionApplication(userId, packageName);
+
+                break;
+            default:
+                Slog.e(TAG, "Event: " + event + "is not supported");
+                break;
+        }
+    }
+
     private void bindApplicationIfNeeded(AssociationInfo association) {
         final String packageName = association.getPackageName();
         final int userId = association.getUserId();
@@ -476,15 +541,26 @@
 
     /**
      * @return whether the package should be bound (i.e. at least one of the devices associated with
-     *         the package is currently present).
+     *         the package is currently present OR the UUID to be observed by this package is
+     *         currently present).
      */
     private boolean shouldBindPackage(@UserIdInt int userId, @NonNull String packageName) {
         final List<AssociationInfo> packageAssociations =
                 mAssociationStore.getAssociationsForPackage(userId, packageName);
+        final List<ObservableUuid> observableUuids =
+                mObservableUuidStore.getObservableUuidsForPackage(userId, packageName);
+
         for (AssociationInfo association : packageAssociations) {
             if (!association.shouldBindWhenPresent()) continue;
             if (mDevicePresenceMonitor.isDevicePresent(association.getId())) return true;
         }
+
+        for (ObservableUuid uuid : observableUuids) {
+            if (mDevicePresenceMonitor.isDeviceUuidPresent(uuid.getUuid())) {
+                return true;
+            }
+        }
+
         return false;
     }
 
@@ -568,6 +644,8 @@
         // Clear associations.
         final List<AssociationInfo> associationsForPackage =
                 mAssociationStore.getAssociationsForPackage(userId, packageName);
+        final List<ObservableUuid> uuidsTobeObserved =
+                mObservableUuidStore.getObservableUuidsForPackage(userId, packageName);
         for (AssociationInfo association : associationsForPackage) {
             mAssociationStore.removeAssociation(association.getId());
         }
@@ -575,6 +653,10 @@
         for (AssociationInfo association : associationsForPackage) {
             maybeRemoveRoleHolderForAssociation(association);
         }
+        // Clear the uuids to be observed.
+        for (ObservableUuid uuid : uuidsTobeObserved) {
+            mObservableUuidStore.removeObservableUuid(userId, uuid.getUuid(), packageName);
+        }
 
         mCompanionAppController.onPackagesChanged(userId);
     }
@@ -855,6 +937,95 @@
         }
 
         @Override
+        @EnforcePermission(REQUEST_OBSERVE_COMPANION_DEVICE_PRESENCE)
+        public void startObservingDevicePresence(ObservingDevicePresenceRequest request,
+                String packageName, int userId) {
+            startObservingDevicePresence_enforcePermission();
+            registerDevicePresenceListener(request, packageName, userId, /* active */ true);
+        }
+
+        @Override
+        @EnforcePermission(REQUEST_OBSERVE_COMPANION_DEVICE_PRESENCE)
+        public void stopObservingDevicePresence(ObservingDevicePresenceRequest request,
+                String packageName, int userId) {
+            stopObservingDevicePresence_enforcePermission();
+            registerDevicePresenceListener(request, packageName, userId, /* active */ false);
+        }
+
+        private void registerDevicePresenceListener(ObservingDevicePresenceRequest request,
+                String packageName, int userId, boolean active) {
+            enforceUsesCompanionDeviceFeature(getContext(), userId, packageName);
+            enforceCallerIsSystemOr(userId, packageName);
+
+            final int associationId = request.getAssociationId();
+            final AssociationInfo associationInfo = mAssociationStore.getAssociationById(
+                    associationId);
+            final ParcelUuid uuid = request.getUuid();
+
+            if (uuid != null) {
+                enforceCallerCanObservingDevicePresenceByUuid(getContext());
+                if (active) {
+                    startObservingDevicePresenceByUuid(uuid, packageName, userId);
+                } else {
+                    stopObservingDevicePresenceByUuid(uuid, packageName, userId);
+                }
+            } else if (associationInfo == null) {
+                throw new IllegalArgumentException("App " + packageName
+                        + " is not associated with device " + request.getAssociationId()
+                        + " for user " + userId);
+            } else {
+                processDevicePresenceListener(
+                        associationInfo, userId, packageName, active);
+            }
+        }
+
+        private void startObservingDevicePresenceByUuid(ParcelUuid uuid, String packageName,
+                int userId) {
+            final List<ObservableUuid> observableUuids =
+                    mObservableUuidStore.getObservableUuidsForPackage(userId, packageName);
+
+            for (ObservableUuid observableUuid : observableUuids) {
+                if (observableUuid.getUuid().equals(uuid)) {
+                    Slog.i(TAG, "The uuid: " + uuid + " for package:" + packageName
+                            + "has been already scheduled for observing");
+                    return;
+                }
+            }
+
+            final ObservableUuid observableUuid = new ObservableUuid(userId, uuid,
+                    packageName, System.currentTimeMillis());
+
+            mObservableUuidStore.writeObservableUuid(userId, observableUuid);
+        }
+
+        private void stopObservingDevicePresenceByUuid(ParcelUuid uuid, String packageName,
+                int userId) {
+            final List<ObservableUuid> uuidsTobeObserved =
+                    mObservableUuidStore.getObservableUuidsForPackage(userId, packageName);
+            boolean isScheduledObserving = false;
+
+            for (ObservableUuid observableUuid : uuidsTobeObserved) {
+                if (observableUuid.getUuid().equals(uuid)) {
+                    isScheduledObserving = true;
+                    break;
+                }
+            }
+
+            if (!isScheduledObserving) {
+                Slog.i(TAG, "The uuid: " + uuid.toString() + " for package:" + packageName
+                        + "has NOT been scheduled for observing yet");
+                return;
+            }
+
+            mObservableUuidStore.removeObservableUuid(userId, uuid, packageName);
+            mDevicePresenceMonitor.removeCurrentConnectedUuidDevice(uuid);
+
+            if (!shouldBindPackage(userId, packageName)) {
+                mCompanionAppController.unbindCompanionApplication(userId, packageName);
+            }
+        }
+
+        @Override
         public PendingIntent buildPermissionTransferUserConsentIntent(String packageName,
                 int userId, int associationId) {
             return mSystemDataTransferProcessor.buildPermissionTransferUserConsentIntent(
@@ -1002,6 +1173,11 @@
                         + " for user " + userId));
             }
 
+            processDevicePresenceListener(association, userId, packageName, active);
+        }
+
+        private void processDevicePresenceListener(AssociationInfo association,
+                int userId, String packageName, boolean active) {
             // If already at specified state, then no-op.
             if (active == association.isNotifyOnDeviceNearby()) {
                 if (DEBUG) Log.d(TAG, "Device presence listener is already at desired state.");
@@ -1025,9 +1201,9 @@
                 if (mDevicePresenceMonitor.isBlePresent(associationId)
                         || mDevicePresenceMonitor.isSimulatePresent(associationId)) {
                     onDeviceAppearedInternal(associationId);
-                    onDeviceEventInternal(associationId, DEVICE_EVENT_BLE_APPEARED);
+                    onDevicePresenceEventInternal(associationId, EVENT_BLE_APPEARED);
                 } else if (mDevicePresenceMonitor.isBtConnected(associationId)) {
-                    onDeviceEventInternal(associationId, DEVICE_EVENT_BT_CONNECTED);
+                    onDevicePresenceEventInternal(associationId, EVENT_BT_CONNECTED);
                 }
             }
 
@@ -1518,20 +1694,25 @@
 
     private final CompanionDevicePresenceMonitor.Callback mDevicePresenceCallback =
             new CompanionDevicePresenceMonitor.Callback() {
-        @Override
-        public void onDeviceAppeared(int associationId) {
-            onDeviceAppearedInternal(associationId);
-        }
+                @Override
+                public void onDeviceAppeared(int associationId) {
+                    onDeviceAppearedInternal(associationId);
+                }
 
-        @Override
-        public void onDeviceDisappeared(int associationId) {
-            onDeviceDisappearedInternal(associationId);
-        }
+                @Override
+                public void onDeviceDisappeared(int associationId) {
+                    onDeviceDisappearedInternal(associationId);
+                }
 
-        @Override
-        public void onDeviceEvent(int associationId, int event) {
-            onDeviceEventInternal(associationId, event);
-        }
+                @Override
+                public void onDevicePresenceEvent(int associationId, int event) {
+                    onDevicePresenceEventInternal(associationId, event);
+                }
+
+                @Override
+                public void onDevicePresenceEventByUuid(ObservableUuid uuid, int event) {
+                    onDevicePresenceEventByUuidInternal(uuid, event);
+                }
     };
 
     private final PackageMonitor mPackageMonitor = new PackageMonitor() {
diff --git a/services/companion/java/com/android/server/companion/CompanionDeviceServiceConnector.java b/services/companion/java/com/android/server/companion/CompanionDeviceServiceConnector.java
index 928842c..5abdb42 100644
--- a/services/companion/java/com/android/server/companion/CompanionDeviceServiceConnector.java
+++ b/services/companion/java/com/android/server/companion/CompanionDeviceServiceConnector.java
@@ -26,6 +26,7 @@
 import android.annotation.UserIdInt;
 import android.companion.AssociationInfo;
 import android.companion.CompanionDeviceService;
+import android.companion.DevicePresenceEvent;
 import android.companion.ICompanionDeviceService;
 import android.content.ComponentName;
 import android.content.Context;
@@ -106,12 +107,11 @@
     void postOnDeviceDisappeared(@NonNull AssociationInfo associationInfo) {
         post(companionService -> companionService.onDeviceDisappeared(associationInfo));
     }
-    void postOnDeviceEvent(@NonNull AssociationInfo associationInfo, int event) {
-        post(companionService -> companionService.onDeviceEvent(associationInfo, event));
+
+    void postOnDevicePresenceEvent(@NonNull DevicePresenceEvent event) {
+        post(companionService -> companionService.onDevicePresenceEvent(event));
     }
 
-
-
     /**
      * Post "unbind" job, which will run *after* all previously posted jobs complete.
      *
diff --git a/services/companion/java/com/android/server/companion/CompanionDeviceShellCommand.java b/services/companion/java/com/android/server/companion/CompanionDeviceShellCommand.java
index e5a8c4f..5663434 100644
--- a/services/companion/java/com/android/server/companion/CompanionDeviceShellCommand.java
+++ b/services/companion/java/com/android/server/companion/CompanionDeviceShellCommand.java
@@ -27,6 +27,7 @@
 import android.companion.datatransfer.PermissionSyncRequest;
 import android.net.MacAddress;
 import android.os.Binder;
+import android.os.ParcelUuid;
 import android.os.ShellCommand;
 import android.util.Base64;
 import android.util.proto.ProtoOutputStream;
@@ -80,6 +81,19 @@
                 mDevicePresenceMonitor.simulateDeviceEvent(associationId, event);
                 return 0;
             }
+
+            if ("simulate-device-uuid-event".equals(cmd) && Flags.devicePresence()) {
+                String uuid = getNextArgRequired();
+                String packageName = getNextArgRequired();
+                int userId = getNextIntArgRequired();
+                int event = getNextIntArgRequired();
+                ObservableUuid observableUuid = new ObservableUuid(
+                        userId, ParcelUuid.fromString(uuid), packageName,
+                        System.currentTimeMillis());
+                mDevicePresenceMonitor.simulateDeviceEventByUuid(observableUuid, event);
+                return 0;
+            }
+
             switch (cmd) {
                 case "list": {
                     final int userId = getNextIntArgRequired();
@@ -447,6 +461,16 @@
             pw.println("    Case(3): ");
             pw.println("      Make CDM act as if the given companion device is BT disconnected ");
             pw.println("      USE FOR DEBUGGING AND/OR TESTING PURPOSES ONLY.");
+
+            pw.println("  simulate-device-uuid-event UUID PACKAGE USERID EVENT");
+            pw.println("  Simulate the companion device event changes:");
+            pw.println("    Case(2): ");
+            pw.println("      Make CDM act as if the given DEVICE is BT connected base"
+                    + "on the UUID");
+            pw.println("    Case(3): ");
+            pw.println("      Make CDM act as if the given DEVICE is BT disconnected base"
+                    + "on the UUID");
+            pw.println("      USE FOR DEBUGGING AND/OR TESTING PURPOSES ONLY.");
         }
 
         pw.println("  remove-inactive-associations");
diff --git a/services/companion/java/com/android/server/companion/ObservableUuid.java b/services/companion/java/com/android/server/companion/ObservableUuid.java
new file mode 100644
index 0000000..6ab3188
--- /dev/null
+++ b/services/companion/java/com/android/server/companion/ObservableUuid.java
@@ -0,0 +1,54 @@
+/*
+ * Copyright (C) 2023 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.server.companion;
+
+import android.annotation.NonNull;
+import android.annotation.UserIdInt;
+import android.os.ParcelUuid;
+
+public class ObservableUuid {
+    private final int mUserId;
+    private final String mPackageName;
+
+    private final ParcelUuid mUuid;
+
+    private final long mTimeApprovedMs;
+
+    public ObservableUuid(@UserIdInt int userId, @NonNull ParcelUuid uuid,
+            @NonNull String packageName, Long timeApprovedMs) {
+        mUserId = userId;
+        mUuid = uuid;
+        mPackageName = packageName;
+        mTimeApprovedMs = timeApprovedMs;
+    }
+
+    public int getUserId() {
+        return mUserId;
+    }
+
+    public ParcelUuid getUuid() {
+        return mUuid;
+    }
+
+    public String getPackageName() {
+        return mPackageName;
+    }
+
+    public long getTimeApprovedMs() {
+        return mTimeApprovedMs;
+    }
+}
diff --git a/services/companion/java/com/android/server/companion/ObservableUuidStore.java b/services/companion/java/com/android/server/companion/ObservableUuidStore.java
new file mode 100644
index 0000000..94be22a
--- /dev/null
+++ b/services/companion/java/com/android/server/companion/ObservableUuidStore.java
@@ -0,0 +1,295 @@
+/*
+ * Copyright (C) 2023 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.server.companion;
+
+import static com.android.internal.util.XmlUtils.readIntAttribute;
+import static com.android.internal.util.XmlUtils.readLongAttribute;
+import static com.android.internal.util.XmlUtils.readStringAttribute;
+import static com.android.internal.util.XmlUtils.writeIntAttribute;
+import static com.android.internal.util.XmlUtils.writeLongAttribute;
+import static com.android.internal.util.XmlUtils.writeStringAttribute;
+import static com.android.server.companion.DataStoreUtils.createStorageFileForUser;
+import static com.android.server.companion.DataStoreUtils.isEndOfTag;
+import static com.android.server.companion.DataStoreUtils.isStartOfTag;
+import static com.android.server.companion.DataStoreUtils.writeToFileSafely;
+
+import android.annotation.NonNull;
+import android.annotation.Nullable;
+import android.annotation.UserIdInt;
+import android.os.ParcelUuid;
+import android.util.AtomicFile;
+import android.util.Slog;
+import android.util.SparseArray;
+import android.util.Xml;
+
+import com.android.internal.annotations.GuardedBy;
+import com.android.internal.util.XmlUtils;
+import com.android.modules.utils.TypedXmlPullParser;
+import com.android.modules.utils.TypedXmlSerializer;
+
+import org.xmlpull.v1.XmlPullParserException;
+
+import java.io.FileInputStream;
+import java.io.IOException;
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.List;
+import java.util.concurrent.ConcurrentHashMap;
+import java.util.concurrent.ConcurrentMap;
+import java.util.concurrent.ExecutionException;
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
+import java.util.concurrent.Future;
+import java.util.concurrent.TimeUnit;
+import java.util.concurrent.TimeoutException;
+
+public class ObservableUuidStore {
+    private static final String TAG = "CDM_ObservableUuidStore";
+    private static final String FILE_NAME = "observing_uuids_presence.xml";
+    private static final String XML_TAG_UUIDS = "uuids";
+    private static final String XML_TAG_UUID = "uuid";
+    private static final String XML_ATTR_UUID = "uuid";
+    private static final String XML_ATTR_TIME_APPROVED = "time_approved";
+    private static final String XML_ATTR_USER_ID = "user_id";
+    private static final String XML_ATTR_PACKAGE = "package_name";
+    private static final int READ_FROM_DISK_TIMEOUT = 5; // in seconds
+
+
+    private final ExecutorService mExecutor;
+    private final ConcurrentMap<Integer, AtomicFile> mUserIdToStorageFile =
+            new ConcurrentHashMap<>();
+
+    private final Object mLock = new Object();
+
+    @GuardedBy("mLock")
+    private final SparseArray<List<ObservableUuid>> mCachedPerUser =
+            new SparseArray<>();
+
+    public ObservableUuidStore() {
+        mExecutor = Executors.newSingleThreadExecutor();
+    }
+
+    /**
+     * Remove the observable uuid from the disk.
+     */
+    void removeObservableUuid(@UserIdInt int userId, ParcelUuid uuid, String packageName) {
+        List<ObservableUuid> cachedObservableUuids;
+
+        synchronized (mLock) {
+            // Remove requests from cache
+            cachedObservableUuids = readObservableUuidsFromCache(userId);
+            cachedObservableUuids.removeIf(
+                    uuid1 -> uuid1.getPackageName().equals(packageName)
+                            && uuid1.getUuid().equals(uuid));
+            mCachedPerUser.set(userId, cachedObservableUuids);
+        }
+        // Remove requests from store
+        mExecutor.execute(() -> writeObservableUuidToStore(userId, cachedObservableUuids));
+    }
+
+    void writeObservableUuid(@UserIdInt int userId, ObservableUuid uuid) {
+        Slog.i(TAG, "Writing uuid=" + uuid.getUuid() + " to store.");
+
+        List<ObservableUuid> cachedObservableUuids;
+        synchronized (mLock) {
+            // Write to cache
+            cachedObservableUuids = readObservableUuidsFromCache(userId);
+            cachedObservableUuids.removeIf(uuid1 -> uuid1.getUuid().equals(
+                    uuid.getUuid()) && uuid1.getPackageName().equals(uuid.getPackageName()));
+            cachedObservableUuids.add(uuid);
+            mCachedPerUser.set(userId, cachedObservableUuids);
+        }
+        // Write to store
+        mExecutor.execute(() -> writeObservableUuidToStore(userId, cachedObservableUuids));
+    }
+
+    private void writeObservableUuidToStore(@UserIdInt int userId,
+            @NonNull List<ObservableUuid> cachedObservableUuids) {
+        final AtomicFile file = getStorageFileForUser(userId);
+        Slog.i(TAG, "Writing ObservableUuid for user " + userId + " to file="
+                + file.getBaseFile().getPath());
+
+        // getStorageFileForUser() ALWAYS returns the SAME OBJECT, which allows us to synchronize
+        // accesses to the file on the file system using this AtomicFile object.
+        synchronized (file) {
+            writeToFileSafely(file, out -> {
+                final TypedXmlSerializer serializer = Xml.resolveSerializer(out);
+                serializer.setFeature(
+                        "http://xmlpull.org/v1/doc/features.html#indent-output", true);
+                serializer.startDocument(null, true);
+                writeObservableUuidToXml(serializer, cachedObservableUuids);
+                serializer.endDocument();
+            });
+        }
+    }
+
+    private void writeObservableUuidToXml(@NonNull TypedXmlSerializer serializer,
+            @Nullable Collection<ObservableUuid> uuids) throws IOException {
+        serializer.startTag(null, XML_TAG_UUIDS);
+
+        for (ObservableUuid uuid : uuids) {
+            writeUuidToXml(serializer, uuid);
+        }
+
+        serializer.endTag(null, XML_TAG_UUIDS);
+    }
+
+    private void writeUuidToXml(@NonNull TypedXmlSerializer serializer,
+            @NonNull ObservableUuid uuid) throws IOException {
+        serializer.startTag(null, XML_TAG_UUID);
+
+        writeIntAttribute(serializer, XML_ATTR_USER_ID, uuid.getUserId());
+        writeStringAttribute(serializer, XML_ATTR_UUID, uuid.getUuid().toString());
+        writeStringAttribute(serializer, XML_ATTR_PACKAGE, uuid.getPackageName());
+        writeLongAttribute(serializer, XML_ATTR_TIME_APPROVED, uuid.getTimeApprovedMs());
+
+        serializer.endTag(null, XML_TAG_UUID);
+    }
+
+    /**
+     * Read the observable UUIDs from the cache.
+     */
+    @GuardedBy("mLock")
+    private List<ObservableUuid> readObservableUuidsFromCache(@UserIdInt int userId) {
+        List<ObservableUuid> cachedObservableUuids = mCachedPerUser.get(userId);
+        if (cachedObservableUuids == null) {
+            Future<List<ObservableUuid>> future =
+                    mExecutor.submit(() -> readObservableUuidFromStore(userId));
+            try {
+                cachedObservableUuids = future.get(READ_FROM_DISK_TIMEOUT, TimeUnit.SECONDS);
+            } catch (InterruptedException e) {
+                Slog.e(TAG, "Thread reading ObservableUuid from disk is "
+                        + "interrupted.");
+            } catch (ExecutionException e) {
+                Slog.e(TAG, "Error occurred while reading ObservableUuid "
+                        + "from disk.");
+            } catch (TimeoutException e) {
+                Slog.e(TAG, "Reading ObservableUuid from disk timed out.");
+            }
+            mCachedPerUser.set(userId, cachedObservableUuids);
+        }
+        return cachedObservableUuids;
+    }
+
+    /**
+     * Reads previously persisted data for the given user
+     *
+     * @param userId Android UserID
+     * @return a list of ObservableUuid
+     */
+    @NonNull
+    public List<ObservableUuid> readObservableUuidFromStore(@UserIdInt int userId) {
+        final AtomicFile file = getStorageFileForUser(userId);
+        Slog.i(TAG, "Reading ObservableUuid for user " + userId + " from "
+                + "file=" + file.getBaseFile().getPath());
+
+        // getStorageFileForUser() ALWAYS returns the SAME OBJECT, which allows us to synchronize
+        // accesses to the file on the file system using this AtomicFile object.
+        synchronized (file) {
+            if (!file.getBaseFile().exists()) {
+                Slog.d(TAG, "File does not exist -> Abort");
+                return new ArrayList<>();
+            }
+            try (FileInputStream in = file.openRead()) {
+                final TypedXmlPullParser parser = Xml.resolvePullParser(in);
+                XmlUtils.beginDocument(parser, XML_TAG_UUIDS);
+
+                return readObservableUuidFromXml(parser);
+            } catch (XmlPullParserException | IOException e) {
+                Slog.e(TAG, "Error while reading requests file", e);
+                return new ArrayList<>();
+            }
+        }
+    }
+
+    @NonNull
+    private List<ObservableUuid> readObservableUuidFromXml(
+            @NonNull TypedXmlPullParser parser) throws XmlPullParserException, IOException {
+        if (!isStartOfTag(parser, XML_TAG_UUIDS)) {
+            throw new XmlPullParserException("The XML doesn't have start tag: " + XML_TAG_UUIDS);
+        }
+
+        List<ObservableUuid> observableUuids = new ArrayList<>();
+
+        while (true) {
+            parser.nextTag();
+            if (isEndOfTag(parser, XML_TAG_UUIDS)) {
+                break;
+            }
+            if (isStartOfTag(parser, XML_TAG_UUID)) {
+                observableUuids.add(readUuidFromXml(parser));
+            }
+        }
+
+        return observableUuids;
+    }
+
+    private ObservableUuid readUuidFromXml(@NonNull TypedXmlPullParser parser)
+            throws XmlPullParserException, IOException {
+        if (!isStartOfTag(parser, XML_TAG_UUID)) {
+            throw new XmlPullParserException("XML doesn't have start tag: " + XML_TAG_UUID);
+        }
+
+        final int userId = readIntAttribute(parser, XML_ATTR_USER_ID);
+        final ParcelUuid uuid = ParcelUuid.fromString(readStringAttribute(parser, XML_ATTR_UUID));
+        final String packageName = readStringAttribute(parser, XML_ATTR_PACKAGE);
+        final Long timeApproved = readLongAttribute(parser, XML_ATTR_TIME_APPROVED);
+
+        return new ObservableUuid(userId, uuid, packageName, timeApproved);
+    }
+
+    /**
+     * Creates and caches {@link AtomicFile} object that represents the back-up file for the given
+     * user.
+     * <p>
+     * IMPORTANT: the method will ALWAYS return the same {@link AtomicFile} object, which makes it
+     * possible to synchronize reads and writes to the file using the returned object.
+     */
+    @NonNull
+    private AtomicFile getStorageFileForUser(@UserIdInt int userId) {
+        return mUserIdToStorageFile.computeIfAbsent(userId,
+                u -> createStorageFileForUser(userId, FILE_NAME));
+    }
+
+    /**
+     * @return A list of ObservableUuids per package.
+     */
+    public List<ObservableUuid> getObservableUuidsForPackage(
+            @UserIdInt int userId, @NonNull String packageName) {
+        final List<ObservableUuid> uuidsTobeObservedPerPackage = new ArrayList<>();
+        synchronized (mLock) {
+            final List<ObservableUuid> uuids = readObservableUuidsFromCache(userId);
+
+            for (ObservableUuid uuid : uuids) {
+                if (uuid.getPackageName().equals(packageName)) {
+                    uuidsTobeObservedPerPackage.add(uuid);
+                }
+            }
+        }
+
+        return uuidsTobeObservedPerPackage;
+    }
+
+    /**
+     * @return A list of ObservableUuids per user.
+     */
+    public List<ObservableUuid> getObservableUuidsForUser(@UserIdInt int userId) {
+        synchronized (mLock) {
+            return readObservableUuidsFromCache(userId);
+        }
+    }
+}
diff --git a/services/companion/java/com/android/server/companion/PermissionsUtils.java b/services/companion/java/com/android/server/companion/PermissionsUtils.java
index f4e14df..15bebba 100644
--- a/services/companion/java/com/android/server/companion/PermissionsUtils.java
+++ b/services/companion/java/com/android/server/companion/PermissionsUtils.java
@@ -19,6 +19,7 @@
 import static android.Manifest.permission.INTERACT_ACROSS_USERS;
 import static android.Manifest.permission.MANAGE_COMPANION_DEVICES;
 import static android.Manifest.permission.REQUEST_COMPANION_SELF_MANAGED;
+import static android.Manifest.permission.REQUEST_OBSERVE_DEVICE_UUID_PRESENCE;
 import static android.app.AppOpsManager.MODE_ALLOWED;
 import static android.companion.AssociationRequest.DEVICE_PROFILE_APP_STREAMING;
 import static android.companion.AssociationRequest.DEVICE_PROFILE_AUTOMOTIVE_PROJECTION;
@@ -174,6 +175,14 @@
                 + " for u" + userId + "/" + packageName);
     }
 
+    static void enforceCallerCanObservingDevicePresenceByUuid(@NonNull Context context) {
+        if (context.checkCallingPermission(REQUEST_OBSERVE_DEVICE_UUID_PRESENCE)
+                != PERMISSION_GRANTED) {
+            throw new SecurityException("Caller (uid=" + getCallingUid() + ") does not have "
+                    + "permissions to request observing device presence base on the UUID");
+        }
+    }
+
     /**
      * Check if the caller is either:
      * <ul>
diff --git a/services/companion/java/com/android/server/companion/presence/BluetoothCompanionDeviceConnectionListener.java b/services/companion/java/com/android/server/companion/presence/BluetoothCompanionDeviceConnectionListener.java
index 6ba85bd..7eca119 100644
--- a/services/companion/java/com/android/server/companion/presence/BluetoothCompanionDeviceConnectionListener.java
+++ b/services/companion/java/com/android/server/companion/presence/BluetoothCompanionDeviceConnectionListener.java
@@ -16,6 +16,9 @@
 
 package com.android.server.companion.presence;
 
+import static android.companion.DevicePresenceEvent.EVENT_BT_CONNECTED;
+import static android.companion.DevicePresenceEvent.EVENT_BT_DISCONNECTED;
+
 import static com.android.server.companion.presence.CompanionDevicePresenceMonitor.DEBUG;
 import static com.android.server.companion.presence.Utils.btDeviceToString;
 
@@ -27,6 +30,7 @@
 import android.net.MacAddress;
 import android.os.Handler;
 import android.os.HandlerExecutor;
+import android.os.ParcelUuid;
 import android.os.UserHandle;
 import android.os.UserManager;
 import android.util.Log;
@@ -35,8 +39,11 @@
 
 import com.android.internal.annotations.GuardedBy;
 import com.android.server.companion.AssociationStore;
+import com.android.server.companion.ObservableUuid;
+import com.android.server.companion.ObservableUuidStore;
 
 import java.util.Arrays;
+import java.util.Collections;
 import java.util.HashMap;
 import java.util.HashSet;
 import java.util.List;
@@ -53,6 +60,8 @@
         void onBluetoothCompanionDeviceConnected(int associationId);
 
         void onBluetoothCompanionDeviceDisconnected(int associationId);
+
+        void onDevicePresenceEventByUuid(ObservableUuid uuid, int event);
     }
 
     private final UserManager mUserManager;
@@ -61,6 +70,8 @@
     /** A set of ALL connected BT device (not only companion.) */
     private final @NonNull Map<MacAddress, BluetoothDevice> mAllConnectedDevices = new HashMap<>();
 
+    private final @NonNull ObservableUuidStore mObservableUuidStore;
+
     /**
      * A structure hold the connected BT devices that are pending to be reported to the companion
      * app when the user unlocks the local device per userId.
@@ -70,8 +81,10 @@
     final SparseArray<Set<BluetoothDevice>> mPendingConnectedDevices = new SparseArray<>();
 
     BluetoothCompanionDeviceConnectionListener(UserManager userManager,
-            @NonNull AssociationStore associationStore, @NonNull Callback callback) {
+            @NonNull AssociationStore associationStore,
+            @NonNull ObservableUuidStore observableUuidStore, @NonNull Callback callback) {
         mAssociationStore = associationStore;
+        mObservableUuidStore = observableUuidStore;
         mCallback = callback;
         mUserManager = userManager;
     }
@@ -109,7 +122,6 @@
                 bluetoothDevices.add(device);
                 mPendingConnectedDevices.put(userId, bluetoothDevices);
             }
-
         } else {
             onDeviceConnectivityChanged(device, true);
         }
@@ -155,8 +167,13 @@
     }
 
     private void onDeviceConnectivityChanged(@NonNull BluetoothDevice device, boolean connected) {
+        int userId = UserHandle.myUserId();
         final List<AssociationInfo> associations =
                 mAssociationStore.getAssociationsByAddress(device.getAddress());
+        final List<ObservableUuid> observableUuids =
+                mObservableUuidStore.getObservableUuidsForUser(userId);
+        final List<ParcelUuid> deviceUuids = device.getUuids() == null
+                ? Collections.emptyList() : Arrays.asList(device.getUuids());
 
         if (DEBUG) {
             Log.d(TAG, "onDevice_ConnectivityChanged() " + btDeviceToString(device)
@@ -177,6 +194,14 @@
                 mCallback.onBluetoothCompanionDeviceDisconnected(id);
             }
         }
+
+        for (ObservableUuid uuid : observableUuids) {
+            if (deviceUuids.contains(uuid.getUuid())) {
+                mCallback.onDevicePresenceEventByUuid(
+                        uuid, connected ? EVENT_BT_CONNECTED
+                                : EVENT_BT_DISCONNECTED);
+            }
+        }
     }
 
     @Override
diff --git a/services/companion/java/com/android/server/companion/presence/CompanionDevicePresenceMonitor.java b/services/companion/java/com/android/server/companion/presence/CompanionDevicePresenceMonitor.java
index e42b935..54a4692 100644
--- a/services/companion/java/com/android/server/companion/presence/CompanionDevicePresenceMonitor.java
+++ b/services/companion/java/com/android/server/companion/presence/CompanionDevicePresenceMonitor.java
@@ -16,12 +16,12 @@
 
 package com.android.server.companion.presence;
 
-import static android.companion.CompanionDeviceService.DEVICE_EVENT_BLE_APPEARED;
-import static android.companion.CompanionDeviceService.DEVICE_EVENT_BLE_DISAPPEARED;
-import static android.companion.CompanionDeviceService.DEVICE_EVENT_BT_CONNECTED;
-import static android.companion.CompanionDeviceService.DEVICE_EVENT_BT_DISCONNECTED;
-import static android.companion.CompanionDeviceService.DEVICE_EVENT_SELF_MANAGED_APPEARED;
-import static android.companion.CompanionDeviceService.DEVICE_EVENT_SELF_MANAGED_DISAPPEARED;
+import static android.companion.DevicePresenceEvent.EVENT_BLE_APPEARED;
+import static android.companion.DevicePresenceEvent.EVENT_BLE_DISAPPEARED;
+import static android.companion.DevicePresenceEvent.EVENT_BT_CONNECTED;
+import static android.companion.DevicePresenceEvent.EVENT_BT_DISCONNECTED;
+import static android.companion.DevicePresenceEvent.EVENT_SELF_MANAGED_APPEARED;
+import static android.companion.DevicePresenceEvent.EVENT_SELF_MANAGED_DISAPPEARED;
 import static android.os.Process.ROOT_UID;
 import static android.os.Process.SHELL_UID;
 
@@ -36,12 +36,15 @@
 import android.os.Handler;
 import android.os.Looper;
 import android.os.Message;
+import android.os.ParcelUuid;
 import android.os.UserManager;
 import android.util.Log;
 import android.util.Slog;
 import android.util.SparseArray;
 
 import com.android.server.companion.AssociationStore;
+import com.android.server.companion.ObservableUuid;
+import com.android.server.companion.ObservableUuidStore;
 
 import java.io.PrintWriter;
 import java.util.HashSet;
@@ -61,7 +64,7 @@
  * <li> {@link #isDevicePresent(int)}
  * <li> {@link Callback#onDeviceAppeared(int) Callback.onDeviceAppeared(int)}
  * <li> {@link Callback#onDeviceDisappeared(int) Callback.onDeviceDisappeared(int)}
- * <li> {@link Callback#onDeviceStateChanged(int, int)}}
+ * <li> {@link Callback#onDevicePresenceEvent(int, int)}}
  * </ul>
  */
 @SuppressLint("LongLogTag")
@@ -78,11 +81,15 @@
         /** Invoked when a companion device no longer seen nearby or disconnects. */
         void onDeviceDisappeared(int associationId);
 
-        /**Invoked when device has corresponding event changes. */
-        void onDeviceEvent(int associationId, int event);
+        /** Invoked when device has corresponding event changes. */
+        void onDevicePresenceEvent(int associationId, int event);
+
+        /** Invoked when device has corresponding event changes base on the UUID */
+        void onDevicePresenceEventByUuid(ObservableUuid uuid, int event);
     }
 
     private final @NonNull AssociationStore mAssociationStore;
+    private final @NonNull ObservableUuidStore mObservableUuidStore;
     private final @NonNull Callback mCallback;
     private final @NonNull BluetoothCompanionDeviceConnectionListener mBtConnectionListener;
     private final @NonNull BleCompanionDeviceScanner mBleScanner;
@@ -94,6 +101,7 @@
     private final @NonNull Set<Integer> mConnectedBtDevices = new HashSet<>();
     private final @NonNull Set<Integer> mNearbyBleDevices = new HashSet<>();
     private final @NonNull Set<Integer> mReportedSelfManagedDevices = new HashSet<>();
+    private final @NonNull Set<ParcelUuid> mConnectedUuidDevices = new HashSet<>();
 
     // Tracking "simulated" presence. Used for debugging and testing only.
     private final @NonNull Set<Integer> mSimulated = new HashSet<>();
@@ -101,11 +109,14 @@
             new SimulatedDevicePresenceSchedulerHelper();
 
     public CompanionDevicePresenceMonitor(UserManager userManager,
-            @NonNull AssociationStore associationStore, @NonNull Callback callback) {
+            @NonNull AssociationStore associationStore,
+            @NonNull ObservableUuidStore observableUuidStore, @NonNull Callback callback) {
         mAssociationStore = associationStore;
+        mObservableUuidStore = observableUuidStore;
         mCallback = callback;
         mBtConnectionListener = new BluetoothCompanionDeviceConnectionListener(userManager,
-                associationStore, /* BluetoothCompanionDeviceConnectionListener.Callback */ this);
+                associationStore, mObservableUuidStore,
+                /* BluetoothCompanionDeviceConnectionListener.Callback */ this);
         mBleScanner = new BleCompanionDeviceScanner(associationStore,
                 /* BleCompanionDeviceScanner.Callback */ this);
     }
@@ -126,6 +137,20 @@
     }
 
     /**
+     * @return current connected UUID devices.
+     */
+    public Set<ParcelUuid> getCurrentConnectedUuidDevices() {
+        return mConnectedUuidDevices;
+    }
+
+    /**
+     * Remove current connected UUID device.
+     */
+    public void removeCurrentConnectedUuidDevice(ParcelUuid uuid) {
+        mConnectedUuidDevices.remove(uuid);
+    }
+
+    /**
      * @return whether the associated companion devices is present. I.e. device is nearby (for BLE);
      *         or devices is connected (for Bluetooth); or reported (by the application) to be
      *         nearby (for "self-managed" associations).
@@ -138,6 +163,13 @@
     }
 
     /**
+     * @return whether the current uuid to be observed is present.
+     */
+    public boolean isDeviceUuidPresent(ParcelUuid uuid) {
+        return mConnectedUuidDevices.contains(uuid);
+    }
+
+    /**
      * @return whether the current device is BT connected and had already reported to the app.
      */
 
@@ -169,8 +201,8 @@
      * {@link android.companion.CompanionDeviceManager#notifyDeviceAppeared(int) notifyDeviceAppeared()}
      */
     public void onSelfManagedDeviceConnected(int associationId) {
-        onDeviceEvent(mReportedSelfManagedDevices,
-                associationId, DEVICE_EVENT_SELF_MANAGED_APPEARED);
+        onDevicePresenceEvent(mReportedSelfManagedDevices,
+                associationId, EVENT_SELF_MANAGED_APPEARED);
     }
 
     /**
@@ -183,23 +215,23 @@
      * {@link android.companion.CompanionDeviceManager#notifyDeviceDisappeared(int) notifyDeviceDisappeared()}
      */
     public void onSelfManagedDeviceDisconnected(int associationId) {
-        onDeviceEvent(mReportedSelfManagedDevices,
-                associationId, DEVICE_EVENT_SELF_MANAGED_DISAPPEARED);
+        onDevicePresenceEvent(mReportedSelfManagedDevices,
+                associationId, EVENT_SELF_MANAGED_DISAPPEARED);
     }
 
     /**
      * Marks a "self-managed" device as disconnected when binderDied.
      */
     public void onSelfManagedDeviceReporterBinderDied(int associationId) {
-        onDeviceEvent(mReportedSelfManagedDevices,
-                associationId, DEVICE_EVENT_SELF_MANAGED_DISAPPEARED);
+        onDevicePresenceEvent(mReportedSelfManagedDevices,
+                associationId, EVENT_SELF_MANAGED_DISAPPEARED);
     }
 
     @Override
     public void onBluetoothCompanionDeviceConnected(int associationId) {
         Slog.i(TAG, "onBluetoothCompanionDeviceConnected: "
                 + "associationId( " + associationId + " )");
-        onDeviceEvent(mConnectedBtDevices, associationId, DEVICE_EVENT_BT_CONNECTED);
+        onDevicePresenceEvent(mConnectedBtDevices, associationId, EVENT_BT_CONNECTED);
         // Stop scanning for BLE devices when this device is connected
         // and there are no other devices to connect to.
         if (canStopBleScan()) {
@@ -214,22 +246,53 @@
         // Start BLE scanning when the device is disconnected.
         mBleScanner.startScan();
 
-        onDeviceEvent(mConnectedBtDevices, associationId, DEVICE_EVENT_BT_DISCONNECTED);
+        onDevicePresenceEvent(mConnectedBtDevices, associationId, EVENT_BT_DISCONNECTED);
     }
 
     @Override
+    public void onDevicePresenceEventByUuid(ObservableUuid uuid, int event) {
+        final ParcelUuid parcelUuid = uuid.getUuid();
+
+        switch(event) {
+            case EVENT_BT_CONNECTED:
+                boolean added = mConnectedUuidDevices.add(parcelUuid);
+
+                if (!added) {
+                    Slog.w(TAG, "Uuid= " + parcelUuid + "is ALREADY reported as "
+                            + "present by this event=" + event);
+                }
+
+                break;
+            case EVENT_BT_DISCONNECTED:
+                final boolean removed = mConnectedUuidDevices.remove(parcelUuid);
+
+                if (!removed) {
+                    Slog.w(TAG, "UUID= " + parcelUuid + " was NOT reported "
+                            + "as present by this event= " + event);
+
+                    return;
+                }
+
+                break;
+        }
+
+        mCallback.onDevicePresenceEventByUuid(uuid, event);
+    }
+
+
+    @Override
     public void onBleCompanionDeviceFound(int associationId) {
-        onDeviceEvent(mNearbyBleDevices, associationId, DEVICE_EVENT_BLE_APPEARED);
+        onDevicePresenceEvent(mNearbyBleDevices, associationId, EVENT_BLE_APPEARED);
     }
 
     @Override
     public void onBleCompanionDeviceLost(int associationId) {
-        onDeviceEvent(mNearbyBleDevices, associationId, DEVICE_EVENT_BLE_DISAPPEARED);
+        onDevicePresenceEvent(mNearbyBleDevices, associationId, EVENT_BLE_DISAPPEARED);
     }
 
     /** FOR DEBUGGING AND/OR TESTING PURPOSES ONLY. */
     @TestApi
-    public void simulateDeviceEvent(int associationId, int state) {
+    public void simulateDeviceEvent(int associationId, int event) {
         // IMPORTANT: this API should only be invoked via the
         // 'companiondevice simulate-device-appeared' Shell command, so the only uid-s allowed to
         // make this call are SHELL and ROOT.
@@ -238,32 +301,43 @@
         // Make sure the association exists.
         enforceAssociationExists(associationId);
 
-        switch (state) {
-            case DEVICE_EVENT_BLE_APPEARED:
-                simulateDeviceAppeared(associationId, state);
+        switch (event) {
+            case EVENT_BLE_APPEARED:
+                simulateDeviceAppeared(associationId, event);
                 break;
-            case DEVICE_EVENT_BT_CONNECTED:
+            case EVENT_BT_CONNECTED:
                 onBluetoothCompanionDeviceConnected(associationId);
                 break;
-            case DEVICE_EVENT_BLE_DISAPPEARED:
-                simulateDeviceDisappeared(associationId, state);
+            case EVENT_BLE_DISAPPEARED:
+                simulateDeviceDisappeared(associationId, event);
                 break;
-            case DEVICE_EVENT_BT_DISCONNECTED:
+            case EVENT_BT_DISCONNECTED:
                 onBluetoothCompanionDeviceDisconnected(associationId);
                 break;
             default:
-                throw new IllegalArgumentException("State: " + state + "is not supported");
+                throw new IllegalArgumentException("Event: " + event + "is not supported");
         }
     }
 
+    /** FOR DEBUGGING AND/OR TESTING PURPOSES ONLY. */
+    @TestApi
+    public void simulateDeviceEventByUuid(ObservableUuid uuid, int event) {
+        // IMPORTANT: this API should only be invoked via the
+        // 'companiondevice simulate-device-uuid-events' Shell command, so the only uid-s allowed to
+        // make this call are SHELL and ROOT.
+        // No other caller (including SYSTEM!) should be allowed.
+        enforceCallerShellOrRoot();
+        onDevicePresenceEventByUuid(uuid, event);
+    }
+
     private void simulateDeviceAppeared(int associationId, int state) {
-        onDeviceEvent(mSimulated, associationId, state);
+        onDevicePresenceEvent(mSimulated, associationId, state);
         mSchedulerHelper.scheduleOnDeviceGoneCallForSimulatedDevicePresence(associationId);
     }
 
     private void simulateDeviceDisappeared(int associationId, int state) {
         mSchedulerHelper.unscheduleOnDeviceGoneCallForSimulatedDevicePresence(associationId);
-        onDeviceEvent(mSimulated, associationId, state);
+        onDevicePresenceEvent(mSimulated, associationId, state);
     }
 
     private void enforceAssociationExists(int associationId) {
@@ -273,14 +347,14 @@
         }
     }
 
-    private void onDeviceEvent(@NonNull Set<Integer> presentDevicesForSource,
+    private void onDevicePresenceEvent(@NonNull Set<Integer> presentDevicesForSource,
             int associationId, int event) {
-        Slog.i(TAG, "onDeviceEvent() id=" + associationId + ", state=" + event);
+        Slog.i(TAG, "onDevicePresenceEvent() id=" + associationId + ", event=" + event);
 
         switch (event) {
-            case DEVICE_EVENT_BLE_APPEARED:
-            case DEVICE_EVENT_BT_CONNECTED:
-            case DEVICE_EVENT_SELF_MANAGED_APPEARED:
+            case EVENT_BLE_APPEARED:
+            case EVENT_BT_CONNECTED:
+            case EVENT_SELF_MANAGED_APPEARED:
                 final boolean added = presentDevicesForSource.add(associationId);
 
                 if (!added) {
@@ -292,9 +366,9 @@
                 mCallback.onDeviceAppeared(associationId);
 
                 break;
-            case DEVICE_EVENT_BLE_DISAPPEARED:
-            case DEVICE_EVENT_BT_DISCONNECTED:
-            case DEVICE_EVENT_SELF_MANAGED_DISAPPEARED:
+            case EVENT_BLE_DISAPPEARED:
+            case EVENT_BT_DISCONNECTED:
+            case EVENT_SELF_MANAGED_DISAPPEARED:
                 final boolean removed = presentDevicesForSource.remove(associationId);
 
                 if (!removed) {
@@ -312,7 +386,7 @@
                 return;
         }
 
-        mCallback.onDeviceEvent(associationId, event);
+        mCallback.onDevicePresenceEvent(associationId, event);
     }
 
     /**
@@ -436,7 +510,7 @@
         public void handleMessage(@NonNull Message msg) {
             final int associationId = msg.what;
             if (mSimulated.contains(associationId)) {
-                onDeviceEvent(mSimulated, associationId, DEVICE_EVENT_BLE_DISAPPEARED);
+                onDevicePresenceEvent(mSimulated, associationId, EVENT_BLE_DISAPPEARED);
             }
         }
     }