blob: 4d6d1175c09a7bd7291df953759e94f68fec5061 [file] [log] [blame]
// 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.
#include <memory>
#include <string>
#include "base/logging.h"
#include "base/macros.h"
#include "base/memory/weak_ptr.h"
#include "content/browser/media/capture/frame_sink_video_capture_device.h"
#include "content/common/content_export.h"
#include "content/public/browser/browser_thread.h"
namespace content {
// Captures the displayed contents of a WebContents, producing a stream of video
// frames.
// Generally, Create() is called with a device ID string that contains
// information necessary for finding a WebContents instance. Thereafter, this
// capture device will capture from the frame sink corresponding to the main
// frame of the RenderFrameHost tree for that WebContents instance. As the
// RenderFrameHost tree mutates (e.g., due to page navigations, crashes, or
// reloads), capture will continue without interruption.
class CONTENT_EXPORT WebContentsVideoCaptureDevice
: public FrameSinkVideoCaptureDevice,
public base::SupportsWeakPtr<WebContentsVideoCaptureDevice> {
WebContentsVideoCaptureDevice(int render_process_id,
int main_render_frame_id);
~WebContentsVideoCaptureDevice() override;
// Creates a WebContentsVideoCaptureDevice instance from the given
// |device_id|. Returns null if |device_id| is invalid.
static std::unique_ptr<WebContentsVideoCaptureDevice> Create(
const std::string& device_id);
// Monitors the WebContents instance and notifies the base class any time the
// frame sink or main render frame's view changes.
class FrameTracker;
// FrameSinkVideoCaptureDevice overrides: These increment/decrement the
// WebContents's capturer count, which causes the embedder to be notified.
void WillStart() final;
void DidStop() final;
// A helper that runs on the UI thread to monitor changes to the
// RenderFrameHost tree during the lifetime of a WebContents instance, and
// posts notifications back to update the target frame sink.
const std::unique_ptr<FrameTracker, BrowserThread::DeleteOnUIThread> tracker_;
} // namespace content