screen_capture_utils.h (3649B)
1 /* 2 * Copyright (c) 2014 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_WIN_SCREEN_CAPTURE_UTILS_H_ 12 #define MODULES_DESKTOP_CAPTURE_WIN_SCREEN_CAPTURE_UTILS_H_ 13 14 #include <optional> 15 #include <string> 16 #include <vector> 17 18 #include "modules/desktop_capture/desktop_capturer.h" 19 #include "modules/desktop_capture/desktop_geometry.h" 20 #include "rtc_base/system/rtc_export.h" 21 22 #if defined(WEBRTC_WIN) 23 // Forward declare HMONITOR in a windows.h compatible way so that we can avoid 24 // including windows.h. 25 #define WEBRTC_DECLARE_HANDLE(name) \ 26 struct name##__; \ 27 typedef struct name##__* name 28 WEBRTC_DECLARE_HANDLE(HMONITOR); 29 #undef WEBRTC_DECLARE_HANDLE 30 #endif 31 32 namespace webrtc { 33 34 // Returns true if the system has at least one active display. 35 bool HasActiveDisplay(); 36 37 // Output the list of active screens into `screens`. Returns true if succeeded, 38 // or false if it fails to enumerate the display devices. If the `device_names` 39 // is provided, it will be filled with the DISPLAY_DEVICE.DeviceName in UTF-8 40 // encoding. If this function returns true, consumers can always assume that 41 // `screens`[i] and `device_names`[i] indicate the same monitor on the system. 42 bool GetScreenList(DesktopCapturer::SourceList* screens, 43 std::vector<std::string>* device_names = nullptr); 44 45 // Converts a device index (which are returned by `GetScreenList`) into an 46 // HMONITOR. 47 bool GetHmonitorFromDeviceIndex(DesktopCapturer::SourceId device_index, 48 HMONITOR* hmonitor); 49 50 // Returns true if `monitor` represents a valid display 51 // monitor. Consumers should recheck the validity of HMONITORs before use if a 52 // WM_DISPLAYCHANGE message has been received. 53 bool IsMonitorValid(HMONITOR monitor); 54 55 // Returns the rect of the monitor identified by `monitor`, relative to the 56 // primary display's top-left. On failure, returns an empty rect. 57 DesktopRect GetMonitorRect(HMONITOR monitor); 58 59 // Returns the DPI for the specified monitor. On failure, returns the system DPI 60 // or the Windows default DPI (96x96) if the system DPI can't be retrieved. 61 DesktopVector GetDpiForMonitor(HMONITOR monitor); 62 63 // Returns true if `screen` is a valid screen. The screen device key is 64 // returned through `device_key` if the screen is valid. The device key can be 65 // used in GetScreenRect to verify the screen matches the previously obtained 66 // id. It calls the EnumDisplayDevices API to check if the screen is valid but 67 // EnumDisplayDevices is quite slow so the caller of this function should 68 // be aware of the performance impact. 69 bool IsScreenValid(DesktopCapturer::SourceId screen, std::wstring* device_key); 70 71 // Get the rect of the entire system in system coordinate system. I.e. the 72 // primary monitor always starts from (0, 0). 73 DesktopRect GetFullscreenRect(); 74 75 // Get the rect of the screen identified by `screen`, relative to the primary 76 // display's top-left. If the optional screen device key exists, and does not 77 // match `device_key`, or the screen does not exist, or any error happens, 78 // an empty rect is returned. 79 RTC_EXPORT DesktopRect 80 GetScreenRect(DesktopCapturer::SourceId screen, 81 const std::optional<std::wstring>& device_key); 82 83 } // namespace webrtc 84 85 #endif // MODULES_DESKTOP_CAPTURE_WIN_SCREEN_CAPTURE_UTILS_H_