Fix buffering behaviour and eventSink bug on iOS

example/ios/Flutter/Flutter.podspec

@@ -0,0 +1,18 @@
+#
+# NOTE: This podspec is NOT to be published. It is only used as a local source!
+#
+
+Pod::Spec.new do |s|
+  s.name             = 'Flutter'
+  s.version          = '1.0.0'
+  s.summary          = 'High-performance, high-fidelity mobile apps.'
+  s.description      = <<-DESC
+Flutter provides an easy and productive way to build and deploy high-performance mobile apps for Android and iOS.
+                       DESC
+  s.homepage         = 'https://flutter.io'
+  s.license          = { :type => 'MIT' }
+  s.author           = { 'Flutter Dev Team' => 'flutter-dev@googlegroups.com' }
+  s.source           = { :git => 'https://github.com/flutter/engine', :tag => s.version.to_s }
+  s.ios.deployment_target = '8.0'
+  s.vendored_frameworks = 'Flutter.framework'
+end

ios/Classes/AudioPlayer.m

@@ -114,6 +114,7 @@
 }
 
 - (void)broadcastPlaybackEvent {
+	if (!_eventSink) return;
 	long long now = (long long)([[NSDate date] timeIntervalSince1970] * 1000.0);
 	_updatePosition = [self getCurrentPosition];
 	_updateTime = now;
@@ -150,6 +151,11 @@
 	[self broadcastPlaybackEvent];
 }
 
+- (void)setPlaybackBufferingState:(enum PlaybackState)state buffering:(BOOL)buffering {
+	_buffering = buffering;
+	[self setPlaybackState:state];
+}
+
 - (void)setUrl:(NSString*)url result:(FlutterResult)result {
 	// TODO: error if already connecting
 	_connectionResult = result;
@@ -271,7 +277,7 @@
 	[_player pause];
 	[_player seekToTime:CMTimeMake(0, 1000)
 	  completionHandler:^(BOOL finished) {
-		  [self setPlaybackState:stopped];
+		  [self setPlaybackBufferingState:stopped buffering:NO];
 	  }];
 }
 
@@ -279,7 +285,7 @@
 	[_player pause];
 	[_player seekToTime:CMTimeMake(0, 1000)
 	  completionHandler:^(BOOL finished) {
-		  [self setPlaybackState:completed];
+		  [self setPlaybackBufferingState:completed buffering:NO];
 	  }];
 }