[expo-av] Prevent debugger from breaking when removing observations (#…

…9334) * [expo-av] Prevent debugger from breaking when removing observations * [expo-av] Remove obversation debug ref count * [expo-av] Update changelog * Update packages/expo-av/ios/EXAV/EXAVPlayerData.m Co-authored-by: Bartłomiej Bukowski <bartlomiejbukowski.b@gmail.com> Co-authored-by: Bartłomiej Bukowski <bartlomiejbukowski.b@gmail.com>
expo · Jul 21, 2020 · 77bc969 · 77bc969
1 parent e6e34f6
commit 77bc969
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diff --git a/packages/expo-av/CHANGELOG.md b/packages/expo-av/CHANGELOG.md
@@ -10,6 +10,7 @@
 
 - Fix audio recording after reload. ([#9283](https://github.com/expo/expo/pull/9283) by [@IjzerenHein](https://github.com/IjzerenHein))
 - Fix fullscreen events not emitted on iOS. ([#9323](https://github.com/expo/expo/pull/9323) by [@IjzerenHein](https://github.com/IjzerenHein))
+- Prevent debugger break when removing observations. ([#9334](https://github.com/expo/expo/pull/9334) by [@IjzerenHein](https://github.com/IjzerenHein))
 
 ## 8.3.0 — 2020-07-08
 

diff --git a/packages/expo-av/ios/EXAV/EXAVPlayerData.m b/packages/expo-av/ios/EXAV/EXAVPlayerData.m
@@ -39,6 +39,7 @@ @interface EXAVPlayerData ()
 @property (nonatomic, strong) id <NSObject> timeObserver;
 @property (nonatomic, strong) id <NSObject> finishObserver;
 @property (nonatomic, strong) id <NSObject> playbackStalledObserver;
+@property (nonatomic, strong) NSMapTable<NSObject *, NSMutableSet<NSString *> *> *observers;
 
 @property (nonatomic, strong) NSNumber *progressUpdateIntervalMillis;
 @property (nonatomic, assign) CMTime currentPosition;
@@ -88,6 +89,7 @@ - (instancetype)initWithEXAV:(EXAV *)exAV
     _finishObserver = nil;
     _playbackStalledObserver = nil;
     _statusUpdateCallback = nil;
+    _observers = [NSMapTable new];
 
     // These status props will be potentially reset by the following call to [self setStatus:parameters ...].
     _progressUpdateIntervalMillis = @(500);
@@ -129,8 +131,8 @@ - (void)_loadNewPlayer
       strongSelf.items = @[firstplayerItem, secondPlayerItem, thirdPlayerItem];
       strongSelf.player = [AVQueuePlayer queuePlayerWithItems:@[firstplayerItem, secondPlayerItem, thirdPlayerItem]];
       if (strongSelf.player) {
-        [strongSelf.player addObserver:strongSelf forKeyPath:EXAVPlayerDataObserverStatusKeyPath options:0 context:nil];
-        [strongSelf.player.currentItem addObserver:strongSelf forKeyPath:EXAVPlayerDataObserverStatusKeyPath options:0 context:nil];
+        [strongSelf _addObserver:strongSelf.player forKeyPath:EXAVPlayerDataObserverStatusKeyPath];
+        [strongSelf _addObserver:strongSelf.player.currentItem forKeyPath:EXAVPlayerDataObserverStatusKeyPath];
       } else {
         NSString *errorMessage = @"Load encountered an error: [AVPlayer playerWithPlayerItem:] returned nil.";
         if (strongSelf.loadFinishBlock) {
@@ -509,12 +511,35 @@ - (void)replayWithStatus:(NSDictionary *)status
 
 #pragma mark - Observers
 
+- (void)_addObserver:(NSObject *)object forKeyPath:(NSString *)path
+{
+  [self _addObserver:object forKeyPath:path options:0];
+}
+
+- (void)_addObserver:(NSObject *)object forKeyPath:(NSString *)path options:(NSKeyValueObservingOptions)options
+{
+  NSMutableSet<NSString *> *set = [_observers objectForKey:object];
+  if (set == nil) {
+    set = [NSMutableSet set];
+    [_observers setObject:set forKey:object];
+  }
+  if (![set containsObject:path]) {
+    [set addObject:path];
+    [object addObserver:self forKeyPath:path options:0 context:nil];
+  }
+}
+
 - (void)_tryRemoveObserver:(NSObject *)object forKeyPath:(NSString *)path
 {
-  @try {
-    [object removeObserver:self forKeyPath:path];
-  } @catch (NSException *exception) {
-    // no-op
+  NSMutableSet<NSString *> *set = [_observers objectForKey:object];
+  if (set) {
+    if ([set containsObject:path]) {
+      [set removeObject:path];
+      if (!set.count) {
+        [_observers removeObjectForKey:object];
+      }
+      [object removeObserver:self forKeyPath:path];
+    }
   }
 }
 
@@ -602,11 +627,8 @@ - (void)_addObserversForPlayerItem:(AVPlayerItem *)playerItem
                                                  object:[_player currentItem]
                                                   queue:nil
                                              usingBlock:playbackStalledObserverBlock];
-  [self _tryRemoveObserver:playerItem forKeyPath:EXAVPlayerDataObserverPlaybackBufferEmptyKeyPath];
-  [playerItem addObserver:self forKeyPath:EXAVPlayerDataObserverPlaybackBufferEmptyKeyPath options:0 context:nil];
-
-  [self _tryRemoveObserver:playerItem forKeyPath:EXAVPlayerDataObserverStatusKeyPath];
-  [playerItem addObserver:self forKeyPath:EXAVPlayerDataObserverStatusKeyPath options:0 context:nil];
+  [self _addObserver:playerItem forKeyPath:EXAVPlayerDataObserverPlaybackBufferEmptyKeyPath];
+  [self _addObserver:playerItem forKeyPath:EXAVPlayerDataObserverStatusKeyPath];
 }
 
 - (void)_updateTimeObserver
@@ -643,15 +665,13 @@ - (void)_addObserversForNewPlayer
   [self _removeObservers];
   [self _updateTimeObserver];
 
-  [_player addObserver:self forKeyPath:EXAVPlayerDataObserverRateKeyPath options:0 context:nil];
+  [self _addObserver:_player forKeyPath:EXAVPlayerDataObserverRateKeyPath];
   NSUInteger currentItemObservationOptions = NSKeyValueObservingOptionOld | NSKeyValueObservingOptionNew;
-  [_player addObserver:self forKeyPath:EXAVPlayerDataObserverCurrentItemKeyPath options:currentItemObservationOptions context:nil];
-  [_player addObserver:self forKeyPath:EXAVPlayerDataObserverTimeControlStatusPath options:0 context:nil]; // Only available after iOS 10
+  [self _addObserver:_player forKeyPath:EXAVPlayerDataObserverCurrentItemKeyPath options:currentItemObservationOptions];
+  [self _addObserver:_player forKeyPath:EXAVPlayerDataObserverTimeControlStatusPath]; // Only available after iOS 10
   [self _addObserversForPlayerItem:_player.currentItem];
 }
 
-
-
 - (void)observeValueForKeyPath:(NSString *)keyPath
                       ofObject:(id)object
                         change:(NSDictionary *)change