From f53329235d5c1e9efdf051838f6a25c6dc5b5cfa Mon Sep 17 00:00:00 2001
From: Lucas Dupin <dupin@google.com>
Date: Tue, 30 Jun 2020 17:12:12 -0700
Subject: [PATCH] Update listener instead of creating a new one

This way we'll avoid cancelling and recreating timers.

Bug: 160036959
Test: atest MediaTimeoutListenerTest
Change-Id: Ic150156cc6078cd6477f48f05c8195d98a6d4fa4
---
 .../systemui/media/MediaTimeoutListener.kt    | 65 +++++++++++--------
 .../media/MediaTimeoutListenerTest.kt         | 16 +++++
 2 files changed, 54 insertions(+), 27 deletions(-)

diff --git a/packages/SystemUI/src/com/android/systemui/media/MediaTimeoutListener.kt b/packages/SystemUI/src/com/android/systemui/media/MediaTimeoutListener.kt
index 8662aacfdab20..6eef131e3a304 100644
--- a/packages/SystemUI/src/com/android/systemui/media/MediaTimeoutListener.kt
+++ b/packages/SystemUI/src/com/android/systemui/media/MediaTimeoutListener.kt
@@ -54,32 +54,35 @@ class MediaTimeoutListener @Inject constructor(
         if (mediaListeners.containsKey(key)) {
             return
         }
-        // Having an old key means that we're migrating from/to resumption. We should invalidate
-        // the old listener and create a new one.
+        // Having an old key means that we're migrating from/to resumption. We should update
+        // the old listener to make sure that events will be dispatched to the new location.
         val migrating = oldKey != null && key != oldKey
         var wasPlaying = false
         if (migrating) {
-            if (mediaListeners.containsKey(oldKey)) {
-                val oldListener = mediaListeners.remove(oldKey)
-                wasPlaying = oldListener?.playing ?: false
-                oldListener?.destroy()
+            val reusedListener = mediaListeners.remove(oldKey)
+            if (reusedListener != null) {
+                wasPlaying = reusedListener.playing ?: false
                 if (DEBUG) Log.d(TAG, "migrating key $oldKey to $key, for resumption")
+                reusedListener.mediaData = data
+                reusedListener.key = key
+                mediaListeners[key] = reusedListener
+                if (wasPlaying != reusedListener.playing) {
+                    // If a player becomes active because of a migration, we'll need to broadcast
+                    // its state. Doing it now would lead to reentrant callbacks, so let's wait
+                    // until we're done.
+                    mainExecutor.execute {
+                        if (mediaListeners[key]?.playing == true) {
+                            if (DEBUG) Log.d(TAG, "deliver delayed playback state for $key")
+                            timeoutCallback.invoke(key, false /* timedOut */)
+                        }
+                    }
+                }
+                return
             } else {
                 Log.w(TAG, "Old key $oldKey for player $key doesn't exist. Continuing...")
             }
         }
         mediaListeners[key] = PlaybackStateListener(key, data)
-
-        // If a player becomes active because of a migration, we'll need to broadcast its state.
-        // Doing it now would lead to reentrant callbacks, so let's wait until we're done.
-        if (migrating && mediaListeners[key]?.playing != wasPlaying) {
-            mainExecutor.execute {
-                if (mediaListeners[key]?.playing == true) {
-                    if (DEBUG) Log.d(TAG, "deliver delayed playback state for $key")
-                    timeoutCallback.invoke(key, false /* timedOut */)
-                }
-            }
-        }
     }
 
     override fun onMediaDataRemoved(key: String) {
@@ -91,26 +94,34 @@ class MediaTimeoutListener @Inject constructor(
     }
 
     private inner class PlaybackStateListener(
-        private val key: String,
+        var key: String,
         data: MediaData
     ) : MediaController.Callback() {
 
         var timedOut = false
         var playing: Boolean? = null
 
+        var mediaData: MediaData = data
+            set(value) {
+                mediaController?.unregisterCallback(this)
+                field = value
+                mediaController = if (field.token != null) {
+                    mediaControllerFactory.create(field.token)
+                } else {
+                    null
+                }
+                mediaController?.registerCallback(this)
+                // Let's register the cancellations, but not dispatch events now.
+                // Timeouts didn't happen yet and reentrant events are troublesome.
+                processState(mediaController?.playbackState, dispatchEvents = false)
+            }
+
         // Resume controls may have null token
-        private val mediaController = if (data.token != null) {
-            mediaControllerFactory.create(data.token)
-        } else {
-            null
-        }
+        private var mediaController: MediaController? = null
         private var cancellation: Runnable? = null
 
         init {
-            mediaController?.registerCallback(this)
-            // Let's register the cancellations, but not dispatch events now.
-            // Timeouts didn't happen yet and reentrant events are troublesome.
-            processState(mediaController?.playbackState, dispatchEvents = false)
+            mediaData = data
         }
 
         fun destroy() {
diff --git a/packages/SystemUI/tests/src/com/android/systemui/media/MediaTimeoutListenerTest.kt b/packages/SystemUI/tests/src/com/android/systemui/media/MediaTimeoutListenerTest.kt
index 7a8e4f7e9b859..f38524369b46b 100644
--- a/packages/SystemUI/tests/src/com/android/systemui/media/MediaTimeoutListenerTest.kt
+++ b/packages/SystemUI/tests/src/com/android/systemui/media/MediaTimeoutListenerTest.kt
@@ -154,6 +154,22 @@ class MediaTimeoutListenerTest : SysuiTestCase() {
         verify(executor).execute(anyObject())
     }
 
+    @Test
+    fun testOnMediaDataLoaded_migratesKeys_noTimeoutExtension() {
+        // From not playing
+        mediaTimeoutListener.onMediaDataLoaded(KEY, null, mediaData)
+        clearInvocations(mediaController)
+
+        // Migrate, still not playing
+        val playingState = mock(android.media.session.PlaybackState::class.java)
+        `when`(playingState.state).thenReturn(PlaybackState.STATE_PAUSED)
+        `when`(mediaController.playbackState).thenReturn(playingState)
+        mediaTimeoutListener.onMediaDataLoaded("NEWKEY", KEY, mediaData)
+
+        // Never cancels callback, or schedule another one
+        verify(cancellationRunnable, never()).run()
+    }
+
     @Test
     fun testOnPlaybackStateChanged_schedulesTimeout_whenPaused() {
         // Assuming we're registered