1 files changed, 116 insertions, 7 deletions
diff --git a/framework/java/android/bluetooth/BluetoothVolumeControl.java b/framework/java/android/bluetooth/BluetoothVolumeControl.java
index 27532aabc3..fb8abb1cf2 100644
--- a/framework/java/android/bluetooth/BluetoothVolumeControl.java
+++ b/framework/java/android/bluetooth/BluetoothVolumeControl.java
@@ -20,6 +20,7 @@ package android.bluetooth;
 import static android.bluetooth.BluetoothUtils.getSyncTimeout;
 
 import android.Manifest;
+import android.annotation.CallbackExecutor;
 import android.annotation.IntRange;
 import android.annotation.NonNull;
 import android.annotation.Nullable;
@@ -40,6 +41,7 @@ import com.android.modules.utils.SynchronousResultReceiver;
 
 import java.util.ArrayList;
 import java.util.List;
+import java.util.concurrent.Executor;
 import java.util.concurrent.TimeoutException;
 
 /**
@@ -59,6 +61,33 @@ public final class BluetoothVolumeControl implements BluetoothProfile, AutoClose
     private CloseGuard mCloseGuard;
 
     /**
+     * This class provides a callback that is invoked when volume offset value changes on
+     * the remote device.
+     *
+     * <p> In order to balance volume on the group of Le Audio devices,
+     * Volume Offset Control Service (VOCS) shall be used. User can verify
+     * if the remote device supports VOCS by calling {@link #isVolumeOffsetAvailable(device)}.
+     *
+     * @hide
+     */
+    @SystemApi
+    public interface Callback {
+        /**
+         * Callback invoked when callback is registered and when volume offset
+         * changes on the remote device. Change can be triggered autonomously by the remote device
+         * or after volume offset change on the user request done by calling
+         * {@link #setVolumeOffset(device, volumeOffset)}
+         *
+         * @param device remote device whose volume offset changed
+         * @param volumeOffset latest volume offset for this device
+         * @hide
+         */
+        @SystemApi
+        void onVolumeOffsetChanged(@NonNull BluetoothDevice device,
+                                   @IntRange(from = -255, to = 255) int volumeOffset);
+    }
+
+    /**
      * Intent used to broadcast the change in connection state of the Volume Control
      * profile.
      *
@@ -217,10 +246,68 @@ public final class BluetoothVolumeControl implements BluetoothProfile, AutoClose
     }
 
     /**
-     * Tells remote device to set an absolute volume.
+     * Register a {@link Callback} that will be invoked during the
+     * operation of this profile.
+     *
+     * Repeated registration of the same <var>callback</var> object will have no effect after
+     * the first call to this method, even when the <var>executor</var> is different. API caller
+     * would have to call {@link #unregisterCallback(Callback)} with
+     * the same callback object before registering it again.
+     *
+     * @param executor an {@link Executor} to execute given callback
+     * @param callback user implementation of the {@link Callback}
+     * @throws IllegalArgumentException if a null executor, sink, or callback is given
+     * @hide
+     */
+    @SystemApi
+    @RequiresBluetoothConnectPermission
+    @RequiresPermission(allOf = {
+            android.Manifest.permission.BLUETOOTH_CONNECT,
+            android.Manifest.permission.BLUETOOTH_PRIVILEGED,
+    })
+    public void registerCallback(@NonNull @CallbackExecutor Executor executor,
+            @NonNull Callback callback) {
+        if (executor == null) {
+            throw new IllegalArgumentException("executor cannot be null");
+        }
+        if (callback == null) {
+            throw new IllegalArgumentException("callback cannot be null");
+        }
+        if (DBG) log("registerCallback");
+        throw new UnsupportedOperationException("Not Implemented");
+    }
+
+    /**
+     * Unregister the specified {@link Callback}.
+     * <p>The same {@link Callback} object used when calling
+     * {@link #registerCallback(Executor, Callback)} must be used.
+     *
+     * <p>Callbacks are automatically unregistered when application process goes away
+     *
+     * @param callback user implementation of the {@link Callback}
+     * @throws IllegalArgumentException when callback is null or when no callback is registered
+     * @hide
+     */
+    @SystemApi
+    @RequiresBluetoothConnectPermission
+    @RequiresPermission(allOf = {
+            android.Manifest.permission.BLUETOOTH_CONNECT,
+            android.Manifest.permission.BLUETOOTH_PRIVILEGED,
+    })
+    public void unregisterCallback(@NonNull Callback callback) {
+        if (callback == null) {
+            throw new IllegalArgumentException("callback cannot be null");
+        }
+        if (DBG) log("unregisterCallback");
+        throw new UnsupportedOperationException("Not Implemented");
+    }
+
+    /**
+     * Tells the remote device to set a volume offset to the absolute volume.
+     *
+     * @param device {@link BluetoothDevice} representing the remote device
+     * @param volumeOffset volume offset to be set on the remote device
      *
-     * @param volume Absolute volume to be set on remote device.
-     *               Minimum value is 0 and maximum value is 255
      * @hide
      */
     @SystemApi
@@ -229,9 +316,9 @@ public final class BluetoothVolumeControl implements BluetoothProfile, AutoClose
             android.Manifest.permission.BLUETOOTH_CONNECT,
             android.Manifest.permission.BLUETOOTH_PRIVILEGED,
     })
-    public void setVolume(@Nullable BluetoothDevice device,
-            @IntRange(from = 0, to = 255) int volume) {
-        if (DBG) log("setVolume(" + volume + ")");
+    public void setVolumeOffset(@NonNull BluetoothDevice device,
+            @IntRange(from = -255, to = 255) int volumeOffset) {
+        if (DBG) log("setVolumeOffset(" + device  + " volumeOffset: " + volumeOffset + ")");
         final IBluetoothVolumeControl service = getService();
         if (service == null) {
             Log.w(TAG, "Proxy not attached to service");
@@ -239,7 +326,7 @@ public final class BluetoothVolumeControl implements BluetoothProfile, AutoClose
         } else if (isEnabled()) {
             try {
                 final SynchronousResultReceiver recv = new SynchronousResultReceiver();
-                service.setVolume(device, volume, mAttributionSource, recv);
+                service.setVolumeOffset(device, volumeOffset, mAttributionSource, recv);
                 recv.awaitResultNoInterrupt(getSyncTimeout()).getValue(null);
             } catch (RemoteException | TimeoutException e) {
                 Log.e(TAG, e.toString() + "\n" + Log.getStackTraceString(new Throwable()));
@@ -248,6 +335,28 @@ public final class BluetoothVolumeControl implements BluetoothProfile, AutoClose
     }
 
     /**
+     * Provides information about the possibility to set volume offset on the remote device.
+     * If the remote device supports Volume Offset Control Service, it is automatically
+     * connected.
+     *
+     * @param device {@link BluetoothDevice} representing the remote device
+     * @return {@code true} if volume offset function is supported and available to use on the
+     *         remote device. When Bluetooth is off, the return value should always be
+     *         {@code false}.
+     * @hide
+     */
+    @SystemApi
+    @RequiresBluetoothConnectPermission
+    @RequiresPermission(allOf = {
+            android.Manifest.permission.BLUETOOTH_CONNECT,
+            android.Manifest.permission.BLUETOOTH_PRIVILEGED,
+    })
+    public boolean isVolumeOffsetAvailable(@NonNull BluetoothDevice device) {
+        if (DBG) log("isVolumeOffsetAvailable(" + device + ")");
+        return false;
+    }
+
+    /**
      * Set connection policy of the profile
      *
      * <p> The device should already be paired.