Add stream of VideoEvent

Author: cbenhagen

packages/video_player/video_player_platform_interface/lib/method_channel_video_player.dart

@@ -93,4 +93,31 @@ class MethodChannelVideoPlayer extends VideoPlayerPlatform {
       ),
     );
   }
+
+  @override
+  Stream<VideoEvent> videoEventsFor(int textureId) {
+    return _eventChannelFor(textureId)
+        .receiveBroadcastStream()
+        .map((dynamic event) {
+      final Map<dynamic, dynamic> map = event;
+      switch (map['event']) {
+        case 'initialized':
+          return VideoEvent.initialized;
+        case 'completed':
+          return VideoEvent.completed;
+        case 'bufferingUpdate':
+          return VideoEvent.bufferingUpdate;
+        case 'bufferingStart':
+          return VideoEvent.bufferingStart;
+        case 'bufferingEnd':
+          return VideoEvent.bufferingEnd;
+        default:
+          return VideoEvent.unknown;
+      }
+    });
+  }
+
+  EventChannel _eventChannelFor(int textureId) {
+    return EventChannel('flutter.io/videoPlayer/videoEvents$textureId');
+  }
 }

packages/video_player/video_player_platform_interface/lib/video_player_platform_interface.dart

@@ -69,13 +69,18 @@ abstract class VideoPlayerPlatform {
   ///
   /// For assets the [asset] key is mandatory. Optionally you can specify
   /// the [package].
-  /// TODO (cbenhagen): create a [DataSourceDescription] class
+  /// TODO (cbenhagen): create a [DataSource] class
   Future<int> create(
     Map<String, dynamic> dataSourceDescription,
   ) {
     throw UnimplementedError('create() has not been implemented.');
   }
 
+  /// Returns a Stream of [VideoEvent]s.
+  Stream<VideoEvent> videoEventsFor(int textureId) {
+    throw UnimplementedError('videoEventsFor() has not been implemented.');
+  }
+
   /// Sets the looping attribute of the video.
   Future<void> setLooping(int textureId, bool looping) {
     throw UnimplementedError('setLooping() has not been implemented.');
@@ -114,3 +119,12 @@ abstract class VideoPlayerPlatform {
   // implemented with `implements`.
   void _verifyProvidesDefaultImplementations() {}
 }
+
+enum VideoEvent {
+  initialized,
+  completed,
+  bufferingUpdate,
+  bufferingStart,
+  bufferingEnd,
+  unknown,
+}

packages/video_player/video_player_platform_interface/test/method_channel_video_player_test.dart

@@ -2,6 +2,8 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
+import 'dart:async';
+
 import 'package:mockito/mockito.dart';
 import 'package:flutter/services.dart';
 import 'package:flutter_test/flutter_test.dart';
@@ -212,6 +214,31 @@ void main() {
       );
       expect(position, const Duration(milliseconds: 234));
     });
+
+    test('videoEventsFor', () async {
+      defaultBinaryMessenger.setMockMessageHandler(
+        "flutter.io/videoPlayer/videoEvents123",
+        (ByteData message) async {
+          final MethodCall methodCall =
+              const StandardMethodCodec().decodeMethodCall(message);
+          if (methodCall.method == 'listen') {
+            defaultBinaryMessenger.handlePlatformMessage(
+                "flutter.io/videoPlayer/videoEvents123",
+                const StandardMethodCodec().encodeSuccessEnvelope(
+                    <String, dynamic>{'event': 'initialized'}),
+                (ByteData data) {});
+
+            return const StandardMethodCodec().encodeSuccessEnvelope(null);
+          } else if (methodCall.method == 'cancel') {
+            return const StandardMethodCodec().encodeSuccessEnvelope(null);
+          } else {
+            fail('Expected listen or cancel');
+          }
+        },
+      );
+      final Stream<VideoEvent> videoEvents = player.videoEventsFor(123);
+      expect(await videoEvents.first, VideoEvent.initialized);
+    });
   });
 }