Split avfoundationcapturer classes in separate files.

webrtc/sdk/objc/Framework/Classes/RTCAVFoundationVideoCapturerInternal.h

+/*
+ *  Copyright 2016 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.
+ */
+
+#import <AVFoundation/AVFoundation.h>
+#import <Foundation/Foundation.h>
+
+#include "avfoundationvideocapturer.h"

[tkchin_webrtc, 2016/11/21 18:51:47]

Don't import C++ headers in ObjC header files. Otherwise you force importers to
support C++.

I know that in this case it doesn't really matter because this class will never
be used by an ObjC class. However, I think it's best to stay consistent in the
codebase where when we import an ObjC header, we know it can be imported into
any ObjC file without converting it to an ObjC++ file (which changes the
compiler from clang to clang++ for the importer).

Forward declare interfaces that you need instead.

In this case you will need some magic by checking #ifdef __cplusplus and add the
namespace for C++ imports, but otherwise declare it as a struct.

[daniela-webrtc, 2016/11/22 11:43:44]

That's great tip! Thanks

[daniela-webrtc, 2016/11/22 11:43:44]

Done.

+
+NS_ASSUME_NONNULL_BEGIN
+// This class is an implementation detail of AVFoundationVideoCapturer and handles
+// the ObjC integration with the AVFoundation APIs.
+// It is meant to be owned by an instance of AVFoundationVideoCapturer.
+// The reason for this is because other webrtc objects own cricket::VideoCapturer, which is not
+// ref counted. To prevent bad behavior we do not expose this class directly.
+
+@interface RTCAVFoundationVideoCapturerInternal
+    : NSObject<AVCaptureVideoDataOutputSampleBufferDelegate>

[tkchin_webrtc, 2016/11/21 18:51:47]

NSObject <AV...

[daniela-webrtc, 2016/11/22 11:43:44]

Done.

+
+@property(nonatomic, readonly) AVCaptureSession *captureSession;
+@property(nonatomic, readonly) dispatch_queue_t frameQueue;
+@property(nonatomic, readonly) BOOL canUseBackCamera;
+@property(nonatomic, assign) BOOL useBackCamera;  // Defaults to NO.
+@property(atomic, assign) BOOL isRunning;  // Whether the capture session is running.
+@property(atomic, assign) BOOL hasStarted;  // Whether we have an unmatched start.
+
+// We keep a pointer back to AVFoundationVideoCapturer to make callbacks on it
+// when we receive frames. This is safe because this object should be owned by
+// it.
+- (instancetype)initWithCapturer:(webrtc::AVFoundationVideoCapturer *)capturer;
+- (AVCaptureDevice *)getActiveCaptureDevice;
+
+- (nullable AVCaptureDevice *)frontCaptureDevice;
+- (nullable AVCaptureDevice *)backCaptureDevice;
+
+// Starts and stops the capture session asynchronously. We cannot do this
+// synchronously without blocking a WebRTC thread.
+- (void)start;
+- (void)stop;
+
+@end
+NS_ASSUME_NONNULL_END