From c1c1358baf8ac8bb4942d08e6ed6ae0f50ca9ccf Mon Sep 17 00:00:00 2001
From: Eric Jensen <jensen39@gmail.com>
Date: Mon, 18 Apr 2016 11:10:45 -0700
Subject: [PATCH] Fix video stalling by pausing the video after backgrounding
 the application

---
 AsyncDisplayKit/ASVideoNode.mm          | 36 +++++++++++++----
 AsyncDisplayKitTests/ASVideoNodeTests.m | 52 ++++++++++++++++++++++++-
 2 files changed, 80 insertions(+), 8 deletions(-)

diff --git a/AsyncDisplayKit/ASVideoNode.mm b/AsyncDisplayKit/ASVideoNode.mm
index 73951d52..8d30ef12 100644
--- a/AsyncDisplayKit/ASVideoNode.mm
+++ b/AsyncDisplayKit/ASVideoNode.mm
@@ -113,6 +113,8 @@ static UIViewContentMode ASContentModeFromVideoGravity(NSString *videoGravity) {
     [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(didPlayToEnd:) name:AVPlayerItemDidPlayToEndTimeNotification object:_currentPlayerItem];
     [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(errorWhilePlaying:) name:AVPlayerItemFailedToPlayToEndTimeNotification object:_currentPlayerItem];
     [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(errorWhilePlaying:) name:AVPlayerItemNewErrorLogEntryNotification object:_currentPlayerItem];
+    [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(willEnterForeground:) name:UIApplicationWillEnterForegroundNotification object:nil];
+    [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(didEnterBackground:) name:UIApplicationDidEnterBackgroundNotification object:nil];
   }
 }
 
@@ -124,6 +126,8 @@ static UIViewContentMode ASContentModeFromVideoGravity(NSString *videoGravity) {
     [[NSNotificationCenter defaultCenter] removeObserver:self name:AVPlayerItemDidPlayToEndTimeNotification object:nil];
     [[NSNotificationCenter defaultCenter] removeObserver:self name:AVPlayerItemFailedToPlayToEndTimeNotification object:nil];
     [[NSNotificationCenter defaultCenter] removeObserver:self name:AVPlayerItemNewErrorLogEntryNotification object:nil];
+    [[NSNotificationCenter defaultCenter] removeObserver:self name:UIApplicationWillEnterForegroundNotification object:nil];
+    [[NSNotificationCenter defaultCenter] removeObserver:self name:UIApplicationDidEnterBackgroundNotification object:nil];
   }
 }
 
@@ -487,8 +491,8 @@ static UIViewContentMode ASContentModeFromVideoGravity(NSString *videoGravity) {
   if ([_delegate respondsToSelector:@selector(videoPlaybackDidFinish:)]) {
     [_delegate videoPlaybackDidFinish:self];
   }
-  [_player seekToTime:CMTimeMakeWithSeconds(0, 1)];
-  
+  [_player seekToTime:kCMTimeZero];
+
   if (_shouldAutorepeat) {
     [self play];
   } else {
@@ -500,19 +504,37 @@ static UIViewContentMode ASContentModeFromVideoGravity(NSString *videoGravity) {
 {
   if ([notification.name isEqualToString:AVPlayerItemFailedToPlayToEndTimeNotification]) {
     NSLog(@"Failed to play video");
-  }
-  else if ([notification.name isEqualToString:AVPlayerItemNewErrorLogEntryNotification]) {
-    AVPlayerItem* item = (AVPlayerItem*)notification.object;
-    AVPlayerItemErrorLogEvent* logEvent = item.errorLog.events.lastObject;
+  } else if ([notification.name isEqualToString:AVPlayerItemNewErrorLogEntryNotification]) {
+    AVPlayerItem *item = (AVPlayerItem *)notification.object;
+    AVPlayerItemErrorLogEvent *logEvent = item.errorLog.events.lastObject;
     NSLog(@"AVPlayerItem error log entry added for video with error %@ status %@", item.error,
           (item.status == AVPlayerItemStatusFailed ? @"FAILED" : [NSString stringWithFormat:@"%ld", (long)item.status]));
     NSLog(@"Item is %@", item);
     
-    if (logEvent)
+    if (logEvent) {
       NSLog(@"Log code %ld domain %@ comment %@", (long)logEvent.errorStatusCode, logEvent.errorDomain, logEvent.errorComment);
+    }
   }
 }
 
+- (void)willEnterForeground:(NSNotification *)notification
+{
+  ASDN::MutexLocker l(_videoLock);
+
+  if (_shouldBePlaying) {
+    [self play];
+  }
+}
+
+- (void)didEnterBackground:(NSNotification *)notification
+{
+  ASDN::MutexLocker l(_videoLock);
+
+  if (_shouldBePlaying) {
+    [self pause];
+    _shouldBePlaying = YES;
+  }
+}
 
 #pragma mark - Property Accessors for Tests
 
diff --git a/AsyncDisplayKitTests/ASVideoNodeTests.m b/AsyncDisplayKitTests/ASVideoNodeTests.m
index 74a42452..f9f3acd9 100644
--- a/AsyncDisplayKitTests/ASVideoNodeTests.m
+++ b/AsyncDisplayKitTests/ASVideoNodeTests.m
@@ -113,7 +113,7 @@
   _videoNode.interfaceState = ASInterfaceStateFetchData;
   
   [_videoNode play];
-  [_videoNode observeValueForKeyPath:@"status" ofObject:[_videoNode currentItem] change:@{@"new" : @(AVPlayerItemStatusReadyToPlay)} context:NULL];
+  [_videoNode observeValueForKeyPath:@"status" ofObject:[_videoNode currentItem] change:@{NSKeyValueChangeNewKey : @(AVPlayerItemStatusReadyToPlay)} context:NULL];
   
   XCTAssertFalse(((UIActivityIndicatorView *)_videoNode.spinner.view).isAnimating);
 }
@@ -282,6 +282,56 @@
   XCTAssertFalse(_videoNode.player.muted);
 }
 
+- (void)testVideoThatDoesNotAutorepeatsShouldPauseOnPlaybackEnd
+{
+  _videoNode.asset = _firstAsset;
+  _videoNode.shouldAutorepeat = NO;
+
+  [_videoNode didLoad];
+  [_videoNode setInterfaceState:ASInterfaceStateVisible | ASInterfaceStateDisplay | ASInterfaceStateFetchData];
+  [_videoNode play];
+
+  XCTAssertTrue(_videoNode.isPlaying);
+
+  [[NSNotificationCenter defaultCenter] postNotificationName:AVPlayerItemDidPlayToEndTimeNotification object:_videoNode.currentItem];
+
+  XCTAssertFalse(_videoNode.isPlaying);
+  XCTAssertEqual(0, CMTimeGetSeconds(_videoNode.player.currentTime));
+}
+
+- (void)testVideoThatAutorepeatsShouldRepeatOnPlaybackEnd
+{
+  _videoNode.asset = _firstAsset;
+  _videoNode.shouldAutorepeat = YES;
+
+  [_videoNode didLoad];
+  [_videoNode setInterfaceState:ASInterfaceStateVisible | ASInterfaceStateDisplay | ASInterfaceStateFetchData];
+  [_videoNode play];
+
+  [[NSNotificationCenter defaultCenter] postNotificationName:AVPlayerItemDidPlayToEndTimeNotification object:_videoNode.currentItem];
+
+  XCTAssertTrue(_videoNode.isPlaying);
+}
+
+- (void)testBackgroundingAndForegroungingTheAppShouldPauseAndResume
+{
+  _videoNode.asset = _firstAsset;
+
+  [_videoNode didLoad];
+  [_videoNode setInterfaceState:ASInterfaceStateVisible | ASInterfaceStateDisplay | ASInterfaceStateFetchData];
+  [_videoNode play];
+
+  XCTAssertTrue(_videoNode.isPlaying);
+
+  [[NSNotificationCenter defaultCenter] postNotificationName:UIApplicationDidEnterBackgroundNotification object:nil];
+
+  XCTAssertFalse(_videoNode.isPlaying);
+
+  [[NSNotificationCenter defaultCenter] postNotificationName:UIApplicationWillEnterForegroundNotification object:nil];
+
+  XCTAssertTrue(_videoNode.isPlaying);
+}
+
 - (void)testSettingVideoGravityChangesPlaceholderContentMode
 {
   [_videoNode setPlaceholderImage:[[UIImage alloc] init]];