Implement screen capturer for macos (based on WebRTC source code).

source/base/desktop/frame.cc

@@ -24,6 +24,10 @@
 
 namespace base {
 
+//--------------------------------------------------------------------------------------------------
+// static
+const float Frame::kStandardDPI = 96.0;
+
 //--------------------------------------------------------------------------------------------------
 Frame::Frame(const Size& size,
              const PixelFormat& format,
@@ -68,6 +72,30 @@ void Frame::copyPixelsFrom(const Frame& src_frame, const Point& src_pos, const R
     copyPixelsFrom(src_frame.frameDataAtPos(src_pos), src_frame.stride(), dest_rect);
 }
 
+//--------------------------------------------------------------------------------------------------
+float Frame::scaleFactor() const
+{
+    float scale = 1.0f;
+
+#if defined(OS_MAC)
+    // At least on Windows the logical and physical pixel are the same
+    // See http://crbug.com/948362.
+    if (dpi() != Point(0, 0) && dpi().x() == dpi().y())
+        scale = dpi().x() / kStandardDPI;
+#endif
+
+    return scale;
+}
+
+//--------------------------------------------------------------------------------------------------
+Rect Frame::rect() const
+{
+    const float scale = scaleFactor();
+    // Only scale the size.
+    return Rect::makeXYWH(topLeft().x(), topLeft().y(),
+                          size().width() / scale, size().height() / scale);
+}
+
 //--------------------------------------------------------------------------------------------------
 uint8_t* Frame::frameDataAtPos(const Point& pos) const
 {

source/base/desktop/frame.h

@@ -30,6 +30,8 @@ class SharedMemoryBase;
 class Frame
 {
 public:
+    static const float kStandardDPI;
+
     virtual ~Frame() = default;
 
     SharedMemoryBase* sharedMemory() const { return shared_memory_; }
@@ -51,6 +53,12 @@ class Frame
     void setTopLeft(const Point& top_left) { top_left_ = top_left; }
     const Point& topLeft() const { return top_left_; }
 
+    void setDpi(const Point& dpi) { dpi_ = dpi; }
+    const Point& dpi() const { return dpi_; }
+
+    float scaleFactor() const;
+    Rect rect() const;
+
     void setCapturerType(uint32_t capturer_type) { capturer_type_ = capturer_type; }
     uint32_t capturerType() const { return capturer_type_; }
 

source/base/desktop/mac/desktop_configuration.h

@@ -52,6 +52,9 @@ struct MacDisplayConfiguration
 
     // Display type, built-in or external.
     bool is_builtin = false;
+
+    // Display primary or not.
+    bool is_primary_ = false;
 };
 
 typedef std::vector<MacDisplayConfiguration> MacDisplayConfigurations;

source/base/desktop/mac/desktop_configuration.mm

@@ -87,6 +87,7 @@ MacDisplayConfiguration getConfigurationForScreen(NSScreen* screen)
 
     // Determine if the display is built-in or external.
     display_config.is_builtin = CGDisplayIsBuiltin(display_config.id);
+    display_config.is_primary_ = CGDisplayIsMain(display_config.id);
 
     return display_config;
 }

source/base/desktop/screen_capturer_mac.h

@@ -21,6 +21,18 @@
 
 #include "base/desktop/screen_capturer.h"
 
+#include "base/desktop/mouse_cursor.h"
+#include "base/desktop/screen_capturer_helper.h"
+#include "base/desktop/shared_frame.h"
+#include "base/desktop/mac/frame_provider.h"
+#include "base/desktop/mac/desktop_configuration.h"
+#include "base/desktop/mac/desktop_configuration_monitor.h"
+#include "base/threading/thread_checker.h"
+
+#include <vector>
+
+#include <AppKit/NSImage.h>
+
 namespace base {
 
 class ScreenCapturerMac : public ScreenCapturer
@@ -43,6 +55,62 @@ class ScreenCapturerMac : public ScreenCapturer
     void reset() override;
 
 private:
+    // Returns false if the selected screen is no longer valid.
+    bool cgBlit(const Frame& frame, const Region& region);
+
+    // Called when the screen configuration is changed.
+    void screenConfigurationChanged();
+
+    bool registerRefreshAndMoveHandlers();
+    void unregisterRefreshAndMoveHandlers();
+
+    void screenRefresh(CGDirectDisplayID display_id, CGRectCount count, const CGRect* rect_array,
+                       const Point& display_origin, IOSurfaceRef io_surface);
+    void releaseBuffers();
+
+    std::unique_ptr<Frame> createFrame();
+
+    const bool detect_updated_region_;
+
+    // Queue of the frames buffers.
+    FrameQueue<SharedFrame> queue_;
+
+    // Current display configuration.
+    MacDesktopConfiguration desktop_config_;
+
+    // Currently selected display, or 0 if the full desktop is selected. On OS X
+    // 10.6 and before, this is always 0.
+    CGDirectDisplayID current_display_ = 0;
+
+    // The physical pixel bounds of the current screen.
+    Rect screen_pixel_bounds_;
+
+    // The dip to physical pixel scale of the current screen.
+    float dip_to_pixel_scale_ = 1.0f;
+
+    // A thread-safe list of invalid rectangles, and the size of the most
+    // recently captured screen.
+    ScreenCapturerHelper helper_;
+
+    // Contains an invalid region from the previous capture.
+    Region last_invalid_region_;
+
+    // Monitoring display reconfiguration.
+    std::shared_ptr<DesktopConfigurationMonitor> desktop_config_monitor_;
+
+    // List of streams, one per screen.
+    std::vector<CGDisplayStreamRef> display_streams_;
+
+    // Container holding latest state of the snapshot per displays.
+    FrameProvider desktop_frame_provider_;
+
+    ScreenId current_screen_id_ = kFullDesktopScreenId;
+
+    __strong NSImage* last_ns_cursor_ = nullptr;
+    std::unique_ptr<MouseCursor> last_cursor_;
+
+    THREAD_CHECKER(thread_checker_);
+
     DISALLOW_COPY_AND_ASSIGN(ScreenCapturerMac);
 };