1/*
2 *  Copyright (c) 2013 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 WEBRTC_MODULES_DESKTOP_CAPTURE_SCREEN_CAPTURER_H_
12#define WEBRTC_MODULES_DESKTOP_CAPTURE_SCREEN_CAPTURER_H_
13
14#include <vector>
15
16#include "webrtc/modules/desktop_capture/desktop_capture_types.h"
17#include "webrtc/modules/desktop_capture/desktop_capturer.h"
18#include "webrtc/system_wrappers/interface/scoped_ptr.h"
19#include "webrtc/typedefs.h"
20
21namespace webrtc {
22
23class DesktopCaptureOptions;
24struct MouseCursorShape;
25
26// Class used to capture video frames asynchronously.
27//
28// The full capture sequence is as follows:
29//
30// (1) Start
31//     This is when pre-capture steps are executed, such as flagging the
32//     display to prevent it from sleeping during a session.
33//
34// (2) CaptureFrame
35//     This is where the bits for the invalid rects are packaged up and sent
36//     to the encoder.
37//     A screen capture is performed if needed. For example, Windows requires
38//     a capture to calculate the diff from the previous screen, whereas the
39//     Mac version does not.
40//
41// Implementation has to ensure the following guarantees:
42// 1. Double buffering
43//    Since data can be read while another capture action is happening.
44class ScreenCapturer : public DesktopCapturer {
45 public:
46  // Use a struct to represent a screen although it has only an id for now,
47  // because we may want to add more fields (e.g. description) in the future.
48  struct Screen {
49    ScreenId id;
50  };
51  typedef std::vector<Screen> ScreenList;
52
53  // Provides callbacks used by the capturer to pass captured video frames and
54  // mouse cursor shapes to the processing pipeline.
55  //
56  // TODO(sergeyu): Move cursor shape capturing to a separate class because it's
57  // unrelated.
58  class MouseShapeObserver {
59   public:
60    // Called when the cursor shape has changed. Must take ownership of
61    // |cursor_shape|.
62    virtual void OnCursorShapeChanged(MouseCursorShape* cursor_shape) = 0;
63
64   protected:
65    virtual ~MouseShapeObserver() {}
66  };
67
68  virtual ~ScreenCapturer() {}
69
70  // Creates platform-specific capturer.
71  //
72  // TODO(sergeyu): Remove all Create() methods except the first one.
73  // crbug.com/172183
74  static ScreenCapturer* Create(const DesktopCaptureOptions& options);
75  static ScreenCapturer* Create();
76
77#if defined(WEBRTC_LINUX)
78  // Creates platform-specific capturer and instructs it whether it should use
79  // X DAMAGE support.
80  static ScreenCapturer* CreateWithXDamage(bool use_x_damage);
81#elif defined(WEBRTC_WIN)
82  // Creates Windows-specific capturer and instructs it whether or not to
83  // disable desktop compositing.
84  static ScreenCapturer* CreateWithDisableAero(bool disable_aero);
85#endif  // defined(WEBRTC_WIN)
86
87  // Called at the beginning of a capturing session. |mouse_shape_observer| must
88  // remain valid until the capturer is destroyed.
89  virtual void SetMouseShapeObserver(
90      MouseShapeObserver* mouse_shape_observer) = 0;
91
92  // Get the list of screens (not containing kFullDesktopScreenId). Returns
93  // false in case of a failure.
94  virtual bool GetScreenList(ScreenList* screens) = 0;
95
96  // Select the screen to be captured. Returns false in case of a failure (e.g.
97  // if there is no screen with the specified id). If this is never called, the
98  // full desktop is captured.
99  virtual bool SelectScreen(ScreenId id) = 0;
100};
101
102}  // namespace webrtc
103
104#endif  // WEBRTC_MODULES_DESKTOP_CAPTURE_SCREEN_CAPTURER_H_
105