New intent for microphone mute change notification

AudioManager: define ACTION_MICROPHONE_MUTE_CHANGED.
AudioService:
 - broadcast intent when setMicrophoneMute() is called
   with FLAG_RECEIVER_REGISTERED_ONLY.
 - remove outdated (invalid) comments.

Bug: 70857126
Test: m -j ; make -j offline-sdk-docs ; make -j cts ; \
      cts-tradefed run cts-dev -m CtsMediaTestCases -t android.media.cts.AudioManagerTest#testMicrophoneMuteIntent

Change-Id: I7391522f0195d06592e4f853e9b672fdec66d37a

3 files changed, 22 insertions, 3 deletions

diff --git a/api/current.txt b/api/current.txt
index 47a338b2363b..2860b59aa98e 100644
--- a/api/current.txt
+++ b/api/current.txt
@@ -21697,6 +21697,7 @@ package android.media {
     field public static final java.lang.String ACTION_AUDIO_BECOMING_NOISY = "android.media.AUDIO_BECOMING_NOISY";
     field public static final java.lang.String ACTION_HDMI_AUDIO_PLUG = "android.media.action.HDMI_AUDIO_PLUG";
     field public static final java.lang.String ACTION_HEADSET_PLUG = "android.intent.action.HEADSET_PLUG";
+    field public static final java.lang.String ACTION_MICROPHONE_MUTE_CHANGED = "android.media.action.MICROPHONE_MUTE_CHANGED";
     field public static final deprecated java.lang.String ACTION_SCO_AUDIO_STATE_CHANGED = "android.media.SCO_AUDIO_STATE_CHANGED";
     field public static final java.lang.String ACTION_SCO_AUDIO_STATE_UPDATED = "android.media.ACTION_SCO_AUDIO_STATE_UPDATED";
     field public static final int ADJUST_LOWER = -1; // 0xffffffff
diff --git a/media/java/android/media/AudioManager.java b/media/java/android/media/AudioManager.java
index f87c8461c7c6..913b5e841112 100644
--- a/media/java/android/media/AudioManager.java
+++ b/media/java/android/media/AudioManager.java
@@ -1635,6 +1635,21 @@ public class AudioManager {
     }
 
     /**
+     * Broadcast Action: microphone muting state changed.
+     *
+     * You <em>cannot</em> receive this through components declared
+     * in manifests, only by explicitly registering for it with
+     * {@link Context#registerReceiver(BroadcastReceiver, IntentFilter)
+     * Context.registerReceiver()}.
+     *
+     * <p>The intent has no extra values, use {@link #isMicrophoneMute} to check whether the
+     * microphone is muted.
+     */
+    @SdkConstant(SdkConstantType.BROADCAST_INTENT_ACTION)
+    public static final String ACTION_MICROPHONE_MUTE_CHANGED =
+            "android.media.action.MICROPHONE_MUTE_CHANGED";
+
+    /**
      * Sets the audio mode.
      * <p>
      * The audio mode encompasses audio routing AND the behavior of
diff --git a/services/core/java/com/android/server/audio/AudioService.java b/services/core/java/com/android/server/audio/AudioService.java
index 6e7b43ef00f3..799f2a92bc33 100644
--- a/services/core/java/com/android/server/audio/AudioService.java
+++ b/services/core/java/com/android/server/audio/AudioService.java
@@ -2251,12 +2251,15 @@ public class AudioService extends IAudioService.Stub
         if (DEBUG_VOL) {
             Log.d(TAG, String.format("Mic mute %s, user=%d", on, userId));
         }
-        // If mute is for current user actually mute, else just persist the setting
-        // which will be loaded on user switch.
+        // only mute for the current user
         if (getCurrentUserId() == userId) {
+            final boolean currentMute = AudioSystem.isMicrophoneMuted();
             AudioSystem.muteMicrophone(on);
+            if (on != currentMute) {
+                mContext.sendBroadcast(new Intent(AudioManager.ACTION_MICROPHONE_MUTE_CHANGED)
+                        .setFlags(Intent.FLAG_RECEIVER_REGISTERED_ONLY));
+            }
         }
-        // Post a persist microphone msg.
     }
 
     @Override