Fix issue 2440226: Car dock volume synchronization.

AudioService now sends intent AudioManager.VOLUME_CHANGED_ACTION  when the volume is changed
on any stream type (previously the intent was sent only for STREAM_BLUETOOTH_SCO stream).
A new extra for previous volume value is added to the intent.

2 files changed, 20 insertions, 9 deletions

diff --git a/media/java/android/media/AudioManager.java b/media/java/android/media/AudioManager.java
index 70c27c2..32c5c23 100644
--- a/media/java/android/media/AudioManager.java
+++ b/media/java/android/media/AudioManager.java
@@ -87,10 +87,11 @@ public class AudioManager {
 
     /**
      * @hide Broadcast intent when the volume for a particular stream type changes.
-     * Includes the stream and the new volume
+     * Includes the stream, the new volume and previous volumes
      *
      * @see #EXTRA_VOLUME_STREAM_TYPE
      * @see #EXTRA_VOLUME_STREAM_VALUE
+     * @see #EXTRA_PREV_VOLUME_STREAM_VALUE
      */
     @SdkConstant(SdkConstantType.BROADCAST_INTENT_ACTION)
     public static final String VOLUME_CHANGED_ACTION = "android.media.VOLUME_CHANGED_ACTION";
@@ -126,6 +127,12 @@ public class AudioManager {
     public static final String EXTRA_VOLUME_STREAM_VALUE =
         "android.media.EXTRA_VOLUME_STREAM_VALUE";
 
+    /**
+     * @hide The previous volume associated with the stream for the volume changed intent.
+     */
+    public static final String EXTRA_PREV_VOLUME_STREAM_VALUE =
+        "android.media.EXTRA_PREV_VOLUME_STREAM_VALUE";
+
     /** The audio stream for phone calls */
     public static final int STREAM_VOICE_CALL = AudioSystem.STREAM_VOICE_CALL;
     /** The audio stream for system sounds */
diff --git a/media/java/android/media/AudioService.java b/media/java/android/media/AudioService.java
index bde8a47..668917e 100644
--- a/media/java/android/media/AudioService.java
+++ b/media/java/android/media/AudioService.java
@@ -403,30 +403,34 @@ public class AudioService extends IAudioService.Stub {
         // UI
         mVolumePanel.postVolumeChanged(streamType, flags);
         // Broadcast Intent
-        sendVolumeUpdate(streamType);
+        sendVolumeUpdate(streamType, oldIndex, streamState.mIndex);
     }
 
     /** @see AudioManager#setStreamVolume(int, int, int) */
     public void setStreamVolume(int streamType, int index, int flags) {
         ensureValidStreamType(streamType);
+
+        final int oldIndex = mStreamStates[STREAM_VOLUME_ALIAS[streamType]].mIndex;
+
         index = rescaleIndex(index * 10, streamType, STREAM_VOLUME_ALIAS[streamType]);
         setStreamVolumeInt(STREAM_VOLUME_ALIAS[streamType], index, false, true);
 
         // UI, etc.
         mVolumePanel.postVolumeChanged(streamType, flags);
         // Broadcast Intent
-        sendVolumeUpdate(streamType);
+        sendVolumeUpdate(streamType, oldIndex, index);
     }
 
-    private void sendVolumeUpdate(int streamType) {
+    private void sendVolumeUpdate(int streamType, int oldIndex, int index) {
+        oldIndex = (oldIndex + 5) / 10;
+        index = (index + 5) / 10;
+
         Intent intent = new Intent(AudioManager.VOLUME_CHANGED_ACTION);
         intent.putExtra(AudioManager.EXTRA_VOLUME_STREAM_TYPE, streamType);
-        intent.putExtra(AudioManager.EXTRA_VOLUME_STREAM_VALUE, getStreamVolume(streamType));
+        intent.putExtra(AudioManager.EXTRA_VOLUME_STREAM_VALUE, index);
+        intent.putExtra(AudioManager.EXTRA_PREV_VOLUME_STREAM_VALUE, oldIndex);
 
-        // Currently, sending the intent only when the stream is BLUETOOTH_SCO
-        if (streamType == AudioSystem.STREAM_BLUETOOTH_SCO) {
-            mContext.sendBroadcast(intent);
-        }
+        mContext.sendBroadcast(intent);
     }
 
     /**