Tweaks for new Objective-C API.

webrtc/api/objc/RTCVideoTrack.mm

 /*
  *  Copyright 2015 The WebRTC project authors. All Rights Reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
@@ skipping 15 matching lines @@
 - (instancetype)initWithFactory:(RTCPeerConnectionFactory *)factory
                          source:(RTCVideoSource *)source
                         trackId:(NSString *)trackId {
   NSParameterAssert(factory);
   NSParameterAssert(source);
   NSParameterAssert(trackId.length);
   std::string nativeId = [NSString stdStringForString:trackId];
   rtc::scoped_refptr<webrtc::VideoTrackInterface> track =
       factory.nativeFactory->CreateVideoTrack(nativeId,
                                               source.nativeVideoSource);
-  return [self initWithNativeTrack:track type:RTCMediaStreamTrackTypeVideo];
+  self = [super initWithNativeTrack:track type:RTCMediaStreamTrackTypeVideo];

[hjon_webrtc, 2016/02/19 20:55:34]

If |source| was actually an RTCAVFoundationVideoSource, calling self resulted in
|_source| becoming an RTCVideoSource instead. In turn, that caused the video
preview in AppRTCDemo to not appear because of this line:
https://code.google.com/p/chromium/codesearch#chromium/src/third_party/webrtc....

For the time being, I was concentrating on getting AppRTCDemo working, so there
might be a better way to fix this that I haven't seen yet.

[tkchin_webrtc, 2016/02/19 23:26:38]

you don't need to re-init the adapters, that should already be there.

to avoid the double source assign/init, lazily load the source in the getter for
the initWithNative case, and then assign source directly for the initWithFactory
case like you already have it.

- (RTCVideoSource *)source {
  if (!_source) {
    _source = ...<stuff from other ctor>
  }
  return _source;
}

[hjon_webrtc, 2016/02/19 23:58:36]

Done.

+  if (self) {
+    _adapters = [NSMutableArray array];
+    _source = source;
+  }
+  return self;
 }
 
-- (instancetype)initWithNativeMediaTrack:
+- (instancetype)initWithNativeTrack:
     (rtc::scoped_refptr<webrtc::MediaStreamTrackInterface>)nativeMediaTrack
-                                    type:(RTCMediaStreamTrackType)type {
+                               type:(RTCMediaStreamTrackType)type {
   NSParameterAssert(nativeMediaTrack);
   NSParameterAssert(type == RTCMediaStreamTrackTypeVideo);
   if (self = [super initWithNativeTrack:nativeMediaTrack type:type]) {
     _adapters = [NSMutableArray array];
     rtc::scoped_refptr<webrtc::VideoSourceInterface> source =
         self.nativeVideoTrack->GetSource();
     if (source) {
       _source = [[RTCVideoSource alloc] initWithNativeVideoSource:source.get()];
     }
   }
@@ skipping 39 matching lines @@
   [_adapters removeObjectAtIndex:indexToRemove];
 }
 
 #pragma mark - Private
 
 - (rtc::scoped_refptr<webrtc::VideoTrackInterface>)nativeVideoTrack {
   return static_cast<webrtc::VideoTrackInterface *>(self.nativeTrack.get());
 }
 
 @end