Support volume-changed sounds on master-volume-only configs

Some products manipulate only the master volume, and the existing
code does not play volume-change tones when the master volume
is adjusted.  This CL includes some config-driven behavior that
will play those tones (via the system stream) if desired.

Bug 6498986

Change-Id: I2415773325d0a0039efc67897bc371b1f2e18063

1 files changed, 20 insertions, 1 deletions

diff --git a/core/java/android/view/VolumePanel.java b/core/java/android/view/VolumePanel.java
index b6e37a6d9eda..6a5677e90594 100644
--- a/core/java/android/view/VolumePanel.java
+++ b/core/java/android/view/VolumePanel.java
@@ -103,6 +103,9 @@ public class VolumePanel extends Handler implements OnSeekBarChangeListener, Vie
     private boolean mShowCombinedVolumes;
     private boolean mVoiceCapable;
 
+    // True if we want to play tones on the system stream when the master stream is specified.
+    private final boolean mPlayMasterStreamTones;
+
     /** Dialog containing all the sliders */
     private final Dialog mDialog;
     /** Dialog's content view */
@@ -275,6 +278,13 @@ public class VolumePanel extends Handler implements OnSeekBarChangeListener, Vie
             mMoreButton.setOnClickListener(this);
         }
 
+        boolean masterVolumeOnly = context.getResources().getBoolean(
+                com.android.internal.R.bool.config_useMasterVolume);
+        boolean masterVolumeKeySounds = mContext.getResources().getBoolean(
+                com.android.internal.R.bool.config_useVolumeKeySounds);
+
+        mPlayMasterStreamTones = masterVolumeOnly && masterVolumeKeySounds;
+
         listenToRingerMode();
     }
 
@@ -657,7 +667,16 @@ public class VolumePanel extends Handler implements OnSeekBarChangeListener, Vie
      * Lock on this VolumePanel instance as long as you use the returned ToneGenerator.
      */
     private ToneGenerator getOrCreateToneGenerator(int streamType) {
-        if (streamType == STREAM_MASTER) return null;
+        if (streamType == STREAM_MASTER) {
+            // For devices that use the master volume setting only but still want to
+            // play a volume-changed tone, direct the master volume pseudostream to
+            // the system stream's tone generator.
+            if (mPlayMasterStreamTones) {
+                streamType = AudioManager.STREAM_SYSTEM;
+            } else {
+                return null;
+            }
+        }
         synchronized (this) {
             if (mToneGenerators[streamType] == null) {
                 try {