Split FakeVideoCaptureDevice into classes with single responsibility

media/capture/video/fake_video_capture_device.h

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-// Implementation of a fake VideoCaptureDevice class. Used for testing other
-// video capture classes when no real hardware is available.
-
 #ifndef MEDIA_CAPTURE_VIDEO_FAKE_VIDEO_CAPTURE_DEVICE_H_
 #define MEDIA_CAPTURE_VIDEO_FAKE_VIDEO_CAPTURE_DEVICE_H_
 
 #include <stdint.h>
 
 #include <memory>
 #include <string>
 
-#include "base/atomicops.h"
-#include "base/macros.h"
-#include "base/memory/weak_ptr.h"
-#include "base/threading/thread_checker.h"
-#include "base/time/time.h"
 #include "media/capture/video/video_capture_device.h"
 
 namespace media {
 
-class CAPTURE_EXPORT FakeVideoCaptureDevice : public VideoCaptureDevice {
+// Encapsulates factory logic to make a working FakeVideoCaptureDevice based
+// on a given target OutputMode and frame rate.
+class CAPTURE_EXPORT FakeVideoCaptureDeviceMaker {
  public:
-  enum class BufferOwnership {
-    OWN_BUFFERS,
-    CLIENT_BUFFERS,
-  };
+  enum class DeliveryMode { USE_OWN_BUFFERS, USE_CLIENT_BUFFERS };
 
-  FakeVideoCaptureDevice(BufferOwnership buffer_ownership,
-                         float fake_capture_rate,
-                         VideoPixelFormat pixel_format = PIXEL_FORMAT_I420);
-  ~FakeVideoCaptureDevice() override;
+  static void GetSupportedSizes(std::vector<gfx::Size>* supported_sizes);
 
-  // VideoCaptureDevice implementation.
-  void AllocateAndStart(const VideoCaptureParams& params,
-                        std::unique_ptr<Client> client) override;
-  void StopAndDeAllocate() override;
-  void GetPhotoCapabilities(GetPhotoCapabilitiesCallback callback) override;
-  void SetPhotoOptions(mojom::PhotoSettingsPtr settings,
-                       SetPhotoOptionsCallback callback) override;
-  void TakePhoto(TakePhotoCallback callback) override;
-
- private:
-  void CaptureUsingOwnBuffers(base::TimeTicks expected_execution_time);
-  void CaptureUsingClientBuffers(base::TimeTicks expected_execution_time);
-  void BeepAndScheduleNextCapture(
-      base::TimeTicks expected_execution_time,
-      const base::Callback<void(base::TimeTicks)>& next_capture);
-
-  // |thread_checker_| is used to check that all methods are called in the
-  // correct thread that owns the object.
-  base::ThreadChecker thread_checker_;
-
-  const BufferOwnership buffer_ownership_;
-  // Frame rate of the fake video device.
-  const float fake_capture_rate_;
-  // Pixel format of all device streams.
-  const VideoPixelFormat pixel_format_;
-
-  std::unique_ptr<VideoCaptureDevice::Client> client_;
-  // |fake_frame_| is used for capturing on Own Buffers.
-  std::unique_ptr<uint8_t[]> fake_frame_;
-  // Time when the next beep occurs.
-  base::TimeDelta beep_time_;
-  // Time since the fake video started rendering frames.
-  base::TimeDelta elapsed_time_;
-  VideoCaptureFormat capture_format_;
-
-  double current_zoom_;
-
-  // The system time when we receive the first frame.
-  base::TimeTicks first_ref_time_;
-  // FakeVideoCaptureDevice post tasks to itself for frame construction and
-  // needs to deal with asynchronous StopAndDeallocate().
-  base::WeakPtrFactory<FakeVideoCaptureDevice> weak_factory_;
-
-  DISALLOW_COPY_AND_ASSIGN(FakeVideoCaptureDevice);
+  static std::unique_ptr<VideoCaptureDevice> MakeInstance(
+      VideoPixelFormat pixel_format,
+      DeliveryMode delivery_mode,
+      float frame_rate);
 };
 
 }  // namespace media
 
 #endif  // MEDIA_CAPTURE_VIDEO_FAKE_VIDEO_CAPTURE_DEVICE_H_