1 /*
2  *  Copyright (c) 2017 The WebRTC project authors. All Rights Reserved.
3  *
4  *  Use of this source code is governed by a BSD-style license
5  *  that can be found in the LICENSE file in the root of the source
6  *  tree. An additional intellectual property rights grant can be found
7  *  in the file PATENTS.  All contributing project authors may
8  *  be found in the AUTHORS file in the root of the source tree.
9  */
10 
11 #ifndef MODULES_DESKTOP_CAPTURE_FALLBACK_DESKTOP_CAPTURER_WRAPPER_H_
12 #define MODULES_DESKTOP_CAPTURE_FALLBACK_DESKTOP_CAPTURER_WRAPPER_H_
13 
14 #include <memory>
15 
16 #include "modules/desktop_capture/desktop_capture_types.h"
17 #include "modules/desktop_capture/desktop_capturer.h"
18 #include "modules/desktop_capture/desktop_frame.h"
19 #include "modules/desktop_capture/desktop_geometry.h"
20 #include "modules/desktop_capture/shared_memory.h"
21 
22 namespace webrtc {
23 
24 // A DesktopCapturer wrapper owns two DesktopCapturer implementations. If the
25 // main DesktopCapturer fails, it uses the secondary one instead. Two capturers
26 // are expected to return same SourceList, and the meaning of each SourceId is
27 // identical, otherwise FallbackDesktopCapturerWrapper may return frames from
28 // different sources. Using asynchronized DesktopCapturer implementations with
29 // SharedMemoryFactory is not supported, and may result crash or assertion
30 // failure.
31 class FallbackDesktopCapturerWrapper final : public DesktopCapturer,
32                                              public DesktopCapturer::Callback {
33  public:
34   FallbackDesktopCapturerWrapper(
35       std::unique_ptr<DesktopCapturer> main_capturer,
36       std::unique_ptr<DesktopCapturer> secondary_capturer);
37   ~FallbackDesktopCapturerWrapper() override;
38 
39   // DesktopCapturer interface.
40   void Start(DesktopCapturer::Callback* callback) override;
41   void SetSharedMemoryFactory(
42       std::unique_ptr<SharedMemoryFactory> shared_memory_factory) override;
43   void CaptureFrame() override;
44   void SetExcludedWindow(WindowId window) override;
45   bool GetSourceList(SourceList* sources) override;
46   bool SelectSource(SourceId id) override;
47   bool FocusOnSelectedSource() override;
48   bool IsOccluded(const DesktopVector& pos) override;
49 
50  private:
51   // DesktopCapturer::Callback interface.
52   void OnCaptureResult(Result result,
53                        std::unique_ptr<DesktopFrame> frame) override;
54 
55   const std::unique_ptr<DesktopCapturer> main_capturer_;
56   const std::unique_ptr<DesktopCapturer> secondary_capturer_;
57   std::unique_ptr<SharedMemoryFactory> shared_memory_factory_;
58   bool main_capturer_permanent_error_ = false;
59   DesktopCapturer::Callback* callback_ = nullptr;
60 };
61 
62 }  // namespace webrtc
63 
64 #endif  // MODULES_DESKTOP_CAPTURE_FALLBACK_DESKTOP_CAPTURER_WRAPPER_H_
65