Merge "Listen for playback state changes" into rvc-dev am: 615aa632b5

Change-Id: If711e44daac81d6faeb048c5b87ae4c938f828be

packages/SystemUI/src/com/android/systemui/media/MediaControlPanel.java

@@ -147,6 +147,7 @@ public class MediaControlPanel {
         if (mSeekBarObserver != null) {
             mSeekBarViewModel.getProgress().removeObserver(mSeekBarObserver);
         }
+        mSeekBarViewModel.onDestroy();
     }
 
     private void loadDimens() {

packages/SystemUI/src/com/android/systemui/media/SeekBarViewModel.kt

@@ -78,7 +78,22 @@ class SeekBarViewModel(val bgExecutor: DelayableExecutor) {
     val progress: LiveData<Progress>
         get() = _progress
     private var controller: MediaController? = null
+        set(value) {
+            if (field?.sessionToken != value?.sessionToken) {
+                field?.unregisterCallback(callback)
+                value?.registerCallback(callback)
+                field = value
+            }
+        }
     private var playbackState: PlaybackState? = null
+    private var callback = object : MediaController.Callback() {
+        override fun onPlaybackStateChanged(state: PlaybackState) {
+            playbackState = state
+            if (shouldPollPlaybackPosition()) {
+                checkPlaybackPosition()
+            }
+        }
+    }
 
     /** Listening state (QS open or closed) is used to control polling of progress. */
     var listening = true
@@ -95,6 +110,9 @@ class SeekBarViewModel(val bgExecutor: DelayableExecutor) {
     @WorkerThread
     fun onSeek(position: Long) {
         controller?.transportControls?.seekTo(position)
+        // Invalidate the cached playbackState to avoid the thumb jumping back to the previous
+        // position.
+        playbackState = null
     }
 
     /**
@@ -125,12 +143,23 @@ class SeekBarViewModel(val bgExecutor: DelayableExecutor) {
      */
     @AnyThread
     fun clearController() = bgExecutor.execute {
+        controller = null
+        playbackState = null
         _data = _data.copy(enabled = false)
     }
 
+    /**
+     * Call to clean up any resources.
+     */
+    @AnyThread
+    fun onDestroy() {
+        controller = null
+        playbackState = null
+    }
+
     @AnyThread
     private fun checkPlaybackPosition(): Runnable = bgExecutor.executeDelayed({
-        val duration = _data?.duration ?: -1
+        val duration = _data.duration ?: -1
         val currentPosition = playbackState?.computePosition(duration.toLong())?.toInt()
         if (currentPosition != null && _data.elapsedTime != currentPosition) {
             _data = _data.copy(elapsedTime = currentPosition)

packages/SystemUI/tests/src/com/android/systemui/media/SeekBarViewModelTest.kt

@@ -18,6 +18,7 @@ package com.android.systemui.media
 
 import android.media.MediaMetadata
 import android.media.session.MediaController
+import android.media.session.MediaSession
 import android.media.session.PlaybackState
 import android.testing.AndroidTestingRunner
 import android.testing.TestableLooper
@@ -35,9 +36,12 @@ import org.junit.After
 import org.junit.Before
 import org.junit.Test
 import org.junit.runner.RunWith
+import org.mockito.ArgumentCaptor
 import org.mockito.Mock
+import org.mockito.Mockito.any
 import org.mockito.Mockito.mock
 import org.mockito.Mockito.never
+import org.mockito.Mockito.times
 import org.mockito.Mockito.verify
 import org.mockito.Mockito.`when` as whenever
 
@@ -61,12 +65,15 @@ public class SeekBarViewModelTest : SysuiTestCase() {
     }
     @Mock private lateinit var mockController: MediaController
     @Mock private lateinit var mockTransport: MediaController.TransportControls
+    private val token1 = MediaSession.Token(1, null)
+    private val token2 = MediaSession.Token(2, null)
 
     @Before
     fun setUp() {
         fakeExecutor = FakeExecutor(FakeSystemClock())
         viewModel = SeekBarViewModel(fakeExecutor)
         mockController = mock(MediaController::class.java)
+        whenever(mockController.sessionToken).thenReturn(token1)
         mockTransport = mock(MediaController.TransportControls::class.java)
 
         // LiveData to run synchronously
@@ -78,6 +85,42 @@ public class SeekBarViewModelTest : SysuiTestCase() {
         ArchTaskExecutor.getInstance().setDelegate(null)
     }
 
+    @Test
+    fun updateRegistersCallback() {
+        viewModel.updateController(mockController)
+        verify(mockController).registerCallback(any())
+    }
+
+    @Test
+    fun updateSecondTimeDoesNotRepeatRegistration() {
+        viewModel.updateController(mockController)
+        viewModel.updateController(mockController)
+        verify(mockController, times(1)).registerCallback(any())
+    }
+
+    @Test
+    fun updateDifferentControllerUnregistersCallback() {
+        viewModel.updateController(mockController)
+        viewModel.updateController(mock(MediaController::class.java))
+        verify(mockController).unregisterCallback(any())
+    }
+
+    @Test
+    fun updateDifferentControllerRegistersCallback() {
+        viewModel.updateController(mockController)
+        val controller2 = mock(MediaController::class.java)
+        whenever(controller2.sessionToken).thenReturn(token2)
+        viewModel.updateController(controller2)
+        verify(controller2).registerCallback(any())
+    }
+
+    @Test
+    fun updateToNullUnregistersCallback() {
+        viewModel.updateController(mockController)
+        viewModel.updateController(null)
+        verify(mockController).unregisterCallback(any())
+    }
+
     @Test
     fun updateDurationWithPlayback() {
         // GIVEN that the duration is contained within the metadata
@@ -374,6 +417,26 @@ public class SeekBarViewModelTest : SysuiTestCase() {
         assertThat(fakeExecutor.numPending()).isEqualTo(1)
     }
 
+    @Test
+    fun playbackChangeQueuesPollTask() {
+        viewModel.updateController(mockController)
+        val captor = ArgumentCaptor.forClass(MediaController.Callback::class.java)
+        verify(mockController).registerCallback(captor.capture())
+        val callback = captor.value
+        // WHEN the callback receives an new state
+        val state = PlaybackState.Builder().run {
+            setState(PlaybackState.STATE_PLAYING, 100L, 1f)
+            build()
+        }
+        callback.onPlaybackStateChanged(state)
+        with(fakeExecutor) {
+            advanceClockToNext()
+            runAllReady()
+        }
+        // THEN an update task is queued
+        assertThat(fakeExecutor.numPending()).isEqualTo(1)
+    }
+
     @Test
     fun clearSeekBar() {
         // GIVEN that the duration is contained within the metadata
@@ -399,4 +462,20 @@ public class SeekBarViewModelTest : SysuiTestCase() {
         // THEN the seek bar is disabled
         assertThat(viewModel.progress.value!!.enabled).isFalse()
     }
+
+    @Test
+    fun clearSeekBarUnregistersCallback() {
+        viewModel.updateController(mockController)
+        viewModel.clearController()
+        fakeExecutor.runAllReady()
+        verify(mockController).unregisterCallback(any())
+    }
+
+    @Test
+    fun destroyUnregistersCallback() {
+        viewModel.updateController(mockController)
+        viewModel.onDestroy()
+        fakeExecutor.runAllReady()
+        verify(mockController).unregisterCallback(any())
+    }
 }