Fix null playstate update from players.

Some players will send a null object as parameter for
playstate change callback, without updating the
MediaSession. These events should still trigger an update
by using the Mediasession metadata if it is different.

Bug: 297191838
Tag: #feature
Test: atest BluetoothInstrumentationTests
Change-Id: Ic5a5b6a68e616af939a4e42d7d64476932dc38d3

android/app/src/com/android/bluetooth/audio_util/MediaPlayerWrapper.java

@@ -461,8 +461,11 @@ public class MediaPlayerWrapper {
         @Override
         public void onMetadataChanged(@Nullable MediaMetadata mediaMetadata) {
             if (!isMetadataReady()) {
-                Log.v(TAG, "onMetadataChanged(): " + mPackageName
-                        + " tried to update with no queue");
+                Log.v(
+                        TAG,
+                        "onMetadataChanged(): "
+                                + mPackageName
+                                + " tried to update with no metadata");
                 return;
             }
 
@@ -495,13 +498,16 @@ public class MediaPlayerWrapper {
         @Override
         public void onPlaybackStateChanged(@Nullable PlaybackState state) {
             if (!isPlaybackStateReady()) {
-                Log.v(TAG, "onPlaybackStateChanged(): " + mPackageName
-                        + " tried to update with no queue");
+                Log.v(
+                        TAG,
+                        "onPlaybackStateChanged(): "
+                                + mPackageName
+                                + " tried to update with no state");
                 return;
             }
 
-            mPlaybackStateChangeEventLogger.logv(TAG, "onPlaybackStateChanged(): "
-                    + mPackageName + " : " + state.toString());
+            mPlaybackStateChangeEventLogger.logv(
+                    TAG, "onPlaybackStateChanged(): " + mPackageName + " : " + state);
 
             if (!playstateEquals(state, getPlaybackState())) {
                 e("The callback playback state doesn't match the current state");
@@ -513,8 +519,8 @@ public class MediaPlayerWrapper {
                 return;
             }
 
-            // If there is no playstate, ignore the update.
-            if (state.getState() == PlaybackState.STATE_NONE) {
+            // If state isn't null and there is no playstate, ignore the update.
+            if (state != null && state.getState() == PlaybackState.STATE_NONE) {
                 Log.v(TAG, "Waiting to send update as controller has no playback state");
                 return;
             }

android/app/tests/unit/src/com/android/bluetooth/audio_util/MediaPlayerWrapperTest.java

@@ -21,7 +21,6 @@ import static com.google.common.truth.Truth.assertThat;
 import static org.mockito.Mockito.*;
 
 import android.content.Context;
-import android.content.pm.PackageManager;
 import android.content.res.Resources;
 import android.graphics.Bitmap;
 import android.graphics.BitmapFactory;
@@ -377,6 +376,38 @@ public class MediaPlayerWrapperTest {
                 Util.toMetadata(mMockContext, mTestMetadata.build()));
     }
 
+    @Test
+    public void testNullPlayback() {
+        // Create the wrapper object and register the looper with the timeout handler
+        TestLooperManager looperManager = new TestLooperManager(mThread.getLooper());
+        MediaPlayerWrapper wrapper =
+                MediaPlayerWrapperFactory.wrap(mMockContext, mMockController, mThread.getLooper());
+        wrapper.registerCallback(mTestCbs);
+
+        // Return null when getting the queue
+        doReturn(null).when(mMockController).getQueue();
+
+        // Grab the callbacks the wrapper registered with the controller
+        verify(mMockController).registerCallback(mControllerCbs.capture(), any());
+        MediaController.Callback controllerCallbacks = mControllerCbs.getValue();
+
+        // Update Metadata returned by controller
+        mTestState.setState(PlaybackState.STATE_PLAYING, 1000, 1.0f);
+        doReturn(mTestState.build()).when(mMockController).getPlaybackState();
+
+        // Call the callback
+        controllerCallbacks.onPlaybackStateChanged(null);
+
+        // Assert that the metadata returned by getPlaybackState() is used instead of null
+
+        verify(mTestCbs, times(1)).mediaUpdatedCallback(mMediaUpdateData.capture());
+        MediaData data = mMediaUpdateData.getValue();
+        Assert.assertEquals(
+                "Returned PlaybackState is incorrect",
+                data.state.toString(),
+                mTestState.build().toString());
+    }
+
     @Test
     public void testNullQueue() {
         // Create the wrapper object and register the looper with the timeout handler