Implement picture in picture for iOS

Test Plan:
 - Run on ipad
 - test out onIsPictureInPictureSupported, onIsPictureInPictureActive, restoreUserInterfaceForPictureInPictureStop, startPictureInPicture, stopPictureInPicture

ios/Video/RCTVideo.h

@@ -16,7 +16,7 @@
 #if __has_include(<react-native-video/RCTVideoCache.h>)
 @interface RCTVideo : UIView <RCTVideoPlayerViewControllerDelegate, DVAssetLoaderDelegatesDelegate>
 #else
-@interface RCTVideo : UIView <RCTVideoPlayerViewControllerDelegate>
+@interface RCTVideo : UIView <RCTVideoPlayerViewControllerDelegate, AVPictureInPictureControllerDelegate>
 #endif
 
 @property (nonatomic, copy) RCTBubblingEventBlock onVideoLoadStart;
@@ -38,6 +38,8 @@
 @property (nonatomic, copy) RCTBubblingEventBlock onPlaybackResume;
 @property (nonatomic, copy) RCTBubblingEventBlock onPlaybackRateChange;
 @property (nonatomic, copy) RCTBubblingEventBlock onVideoExternalPlaybackChange;
+@property (nonatomic, copy) RCTBubblingEventBlock onIsPictureInPictureSupported;
+@property (nonatomic, copy) RCTBubblingEventBlock onIsPictureInPictureActive;
 
 - (instancetype)initWithEventDispatcher:(RCTEventDispatcher *)eventDispatcher NS_DESIGNATED_INITIALIZER;
 

ios/Video/RCTVideo.m

@@ -27,6 +27,8 @@ static int const RCTVideoUnset = -1;
   AVPlayer *_player;
   AVPlayerItem *_playerItem;
   NSDictionary *_source;
+  AVPictureInPictureController *_pipController;
+  void (^__strong _Nonnull _restoreUserInterfaceForPIPStopCompletionHandler)(BOOL);
   BOOL _playerItemObserversSet;
   BOOL _playerBufferEmpty;
   AVPlayerLayer *_playerLayer;
@@ -101,6 +103,7 @@ static int const RCTVideoUnset = -1;
     _allowsExternalPlayback = YES;
     _playWhenInactive = false;
     _ignoreSilentSwitch = @"inherit"; // inherit, ignore, obey
+	_restoreUserInterfaceForPIPStopCompletionHandler = NULL;
 #if __has_include(<react-native-video/RCTVideoCache.h>)
     _videoCache = [RCTVideoCache sharedInstance];
 #endif
@@ -379,6 +382,12 @@ static int const RCTVideoUnset = -1;
                                     @"target": self.reactTag
                                 });
       }
+
+      if (@available(iOS 9, *)) {
+        if (self.onIsPictureInPictureSupported) {
+          self.onIsPictureInPictureSupported(@{@"supported": [NSNumber numberWithBool:(bool)[AVPictureInPictureController isPictureInPictureSupported]]});
+        }
+      }
     }];
   });
   _videoLoadStarted = YES;
@@ -780,6 +789,37 @@ static int const RCTVideoUnset = -1;
   _playWhenInactive = playWhenInactive;
 }
 
+- (void)setPictureInPicture:(BOOL)pictureInPicture
+{
+  if (_pipController && pictureInPicture && ![_pipController isPictureInPictureActive]) {
+    dispatch_async(dispatch_get_main_queue(), ^{
+      [_pipController startPictureInPicture];
+    });
+  } else if (_pipController && !pictureInPicture && [_pipController isPictureInPictureActive]) {
+    dispatch_async(dispatch_get_main_queue(), ^{
+      [_pipController stopPictureInPicture];
+	});
+  }
+}
+
+- (void)setRestoreUserInterfaceForPIPStopCompletionHandler:(BOOL)restore
+{
+  if (_restoreUserInterfaceForPIPStopCompletionHandler != NULL) {
+    _restoreUserInterfaceForPIPStopCompletionHandler(restore);
+    _restoreUserInterfaceForPIPStopCompletionHandler = NULL;
+  }
+}
+
+- (void)setupPipController {
+  if (@available(iOS 9, *)) {
+    if (!_pipController && _playerLayer && [AVPictureInPictureController isPictureInPictureSupported]) {
+	  // Create new controller passing reference to the AVPlayerLayer
+      _pipController = [[AVPictureInPictureController alloc] initWithPlayerLayer:_playerLayer];
+      _pipController.delegate = self;
+    }
+  }
+}
+
 - (void)setIgnoreSilentSwitch:(NSString *)ignoreSilentSwitch
 {
   _ignoreSilentSwitch = ignoreSilentSwitch;
@@ -1234,6 +1274,8 @@ static int const RCTVideoUnset = -1;
     
     [self.layer addSublayer:_playerLayer];
     self.layer.needsDisplayOnBoundsChange = YES;
+
+    [self setupPipController];
   }
 }
 
@@ -1490,4 +1532,35 @@ static int const RCTVideoUnset = -1;
     return array[0];
 }
 
+#pragma mark - Picture in Picture
+
+- (void)pictureInPictureControllerDidStopPictureInPicture:(AVPictureInPictureController *)pictureInPictureController {
+  if (self.onIsPictureInPictureActive && _pipController) {
+    self.onIsPictureInPictureActive(@{@"active": [NSNumber numberWithBool:false]});
+  }
+}
+
+- (void)pictureInPictureControllerDidStartPictureInPicture:(AVPictureInPictureController *)pictureInPictureController {
+  if (self.onIsPictureInPictureActive && _pipController) {
+    self.onIsPictureInPictureActive(@{@"active": [NSNumber numberWithBool:true]});
+  }
+}
+
+- (void)pictureInPictureControllerWillStopPictureInPicture:(AVPictureInPictureController *)pictureInPictureController {
+
+}
+
+- (void)pictureInPictureControllerWillStartPictureInPicture:(AVPictureInPictureController *)pictureInPictureController {
+
+}
+
+- (void)pictureInPictureController:(AVPictureInPictureController *)pictureInPictureController failedToStartPictureInPictureWithError:(NSError *)error {
+
+}
+
+- (void)pictureInPictureController:(AVPictureInPictureController *)pictureInPictureController restoreUserInterfaceForPictureInPictureStopWithCompletionHandler:(void (^)(BOOL))completionHandler {
+  NSAssert(_restoreUserInterfaceForPIPStopCompletionHandler == NULL, @"restoreUserInterfaceForPIPStopCompletionHandler was not called after picture in picture was exited.");
+  _restoreUserInterfaceForPIPStopCompletionHandler = completionHandler;
+}
+
 @end

ios/Video/RCTVideoManager.m

@@ -42,6 +42,8 @@ RCT_EXPORT_VIEW_PROPERTY(fullscreenOrientation, NSString);
 RCT_EXPORT_VIEW_PROPERTY(filter, NSString);
 RCT_EXPORT_VIEW_PROPERTY(filterEnabled, BOOL);
 RCT_EXPORT_VIEW_PROPERTY(progressUpdateInterval, float);
+RCT_EXPORT_VIEW_PROPERTY(pictureInPicture, BOOL);
+RCT_EXPORT_VIEW_PROPERTY(restoreUserInterfaceForPIPStopCompletionHandler, BOOL);
 /* Should support: onLoadStart, onLoad, and onError to stay consistent with Image */
 RCT_EXPORT_VIEW_PROPERTY(onVideoLoadStart, RCTBubblingEventBlock);
 RCT_EXPORT_VIEW_PROPERTY(onVideoLoad, RCTBubblingEventBlock);
@@ -77,6 +79,8 @@ RCT_REMAP_METHOD(save,
         }
     }];
 }
+RCT_EXPORT_VIEW_PROPERTY(onIsPictureInPictureSupported, RCTBubblingEventBlock);
+RCT_EXPORT_VIEW_PROPERTY(onIsPictureInPictureActive, RCTBubblingEventBlock);
 
 - (NSDictionary *)constantsToExport
 {