[Mojo Video Capture] Introduce abstraction BuildableVideoCaptureDevice

content/browser/renderer_host/media/buildable_video_capture_device.h

+// Copyright 2016 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.
+
+#ifndef CONTENT_BROWSER_RENDERER_HOST_MEDIA_BUILDABLE_VIDEO_CAPTURE_DEVICE_H_
+#define CONTENT_BROWSER_RENDERER_HOST_MEDIA_BUILDABLE_VIDEO_CAPTURE_DEVICE_H_
+
+#include "base/memory/ptr_util.h"
+#include "base/memory/ref_counted.h"
+#include "content/browser/renderer_host/media/ownership.h"
+#include "content/public/common/media_stream_request.h"
+#include "media/capture/video/video_capture_device.h"
+#include "media/capture/video_capture_types.h"
+
+namespace content {
+
+class VideoCaptureController;
+
+class CONTENT_EXPORT BuildableDeviceCallbacks {
+ public:
+  virtual ~BuildableDeviceCallbacks() {}
+  // Returns false if no descriptor was found.
+  virtual const media::VideoCaptureDeviceDescriptor* LookupDeviceDescriptor(
+      const std::string& id) = 0;
+  virtual void WillStartDevice(media::VideoFacingMode facing_mode) = 0;
+  virtual void DidStartDevice(VideoCaptureController* entry) = 0;
+  virtual void OnDeviceStartFailed(VideoCaptureController* entry) = 0;
+};
+
+// Abstraction for a video capture device that must be "built" before it can be
+// operated and must be "stopped", before it can be released. Typical operation
+// is that a newly created instance initially reports IsDeviceAlive() == false.
+// Clients call CreateAndStartDeviceAsync(), which kicks off the asynchronous
+// building of the device. The outcome of the device building is typically
+// reported to an instance of BuildableDeviceCallbacks (see above). Once the
+// device has been built successfully, the "Device operation methods", are
+// allowed to be called. ReleaseDeviceAsync() must be called in order to
+// release the device if it has before been built successfully. After calling
+// ReleaseDeviceAsync(), it is legal to call CreateAndStartDeviceAsync() to
+// rebuild and start the device again.
+class BuildableVideoCaptureDevice {
+ public:
+  virtual ~BuildableVideoCaptureDevice() {}
+
+  // Device management methods.
+  // The passed-in |context_reference| must guarantee that the context relevant
+  // during the asynchronous processing stays alive.
+  virtual void CreateAndStartDeviceAsync(
+      VideoCaptureController* entry,
+      VideoCaptureController* controller,
+      const media::VideoCaptureParams& params,
+      BuildableDeviceCallbacks* callbacks,
+      std::unique_ptr<Ownership> context_reference) = 0;
+  // The passed-in |context_reference| must guarantee that the context relevant
+  // during the asynchronous processing stays alive.
+  virtual void ReleaseDeviceAsync(
+      VideoCaptureController* controller,
+      std::unique_ptr<Ownership> context_reference) = 0;
+  virtual bool IsDeviceAlive() const = 0;
+
+  // Device operation methods.
+  virtual void GetPhotoCapabilities(
+      media::VideoCaptureDevice::GetPhotoCapabilitiesCallback callback)
+      const = 0;
+  virtual void SetPhotoOptions(
+      media::mojom::PhotoSettingsPtr settings,
+      media::VideoCaptureDevice::SetPhotoOptionsCallback callback) = 0;
+  virtual void TakePhoto(
+      media::VideoCaptureDevice::TakePhotoCallback callback) = 0;
+  virtual void MaybeSuspendDevice() = 0;
+  virtual void ResumeDevice() = 0;
+  virtual void RequestRefreshFrame() = 0;
+
+  // Methods for specific types of devices.
+  // The passed-in |context_reference| must guarantee that the context relevant
+  // during the asynchronous processing stays alive.
+  virtual void SetDesktopCaptureWindowIdAsync(
+      gfx::NativeViewId window_id,
+      std::unique_ptr<Ownership> context_reference) = 0;
+};
+
+}  // namespace content
+
+#endif  // CONTENT_BROWSER_RENDERER_HOST_MEDIA_BUILDABLE_VIDEO_CAPTURE_DEVICE_H_