1 files changed, 209 insertions, 0 deletions
diff --git a/third_party/libwebrtc/modules/desktop_capture/screen_drawer_win.cc b/third_party/libwebrtc/modules/desktop_capture/screen_drawer_win.cc
new file mode 100644
index 0000000000..7cf634fe89
--- /dev/null
+++ b/third_party/libwebrtc/modules/desktop_capture/screen_drawer_win.cc
@@ -0,0 +1,209 @@
+/*
+ *  Copyright (c) 2016 The WebRTC project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#include <windows.h>
+
+#include <memory>
+
+#include "modules/desktop_capture/screen_drawer.h"
+#include "system_wrappers/include/sleep.h"
+
+namespace webrtc {
+
+namespace {
+
+static constexpr TCHAR kMutexName[] =
+    TEXT("Local\\ScreenDrawerWin-da834f82-8044-11e6-ac81-73dcdd1c1869");
+
+class ScreenDrawerLockWin : public ScreenDrawerLock {
+ public:
+  ScreenDrawerLockWin();
+  ~ScreenDrawerLockWin() override;
+
+ private:
+  HANDLE mutex_;
+};
+
+ScreenDrawerLockWin::ScreenDrawerLockWin() {
+  while (true) {
+    mutex_ = CreateMutex(NULL, FALSE, kMutexName);
+    if (GetLastError() != ERROR_ALREADY_EXISTS && mutex_ != NULL) {
+      break;
+    } else {
+      if (mutex_) {
+        CloseHandle(mutex_);
+      }
+      SleepMs(1000);
+    }
+  }
+}
+
+ScreenDrawerLockWin::~ScreenDrawerLockWin() {
+  CloseHandle(mutex_);
+}
+
+DesktopRect GetScreenRect() {
+  HDC hdc = GetDC(NULL);
+  DesktopRect rect = DesktopRect::MakeWH(GetDeviceCaps(hdc, HORZRES),
+                                         GetDeviceCaps(hdc, VERTRES));
+  ReleaseDC(NULL, hdc);
+  return rect;
+}
+
+HWND CreateDrawerWindow(DesktopRect rect) {
+  HWND hwnd = CreateWindowA(
+      "STATIC", "DrawerWindow", WS_POPUPWINDOW | WS_VISIBLE, rect.left(),
+      rect.top(), rect.width(), rect.height(), NULL, NULL, NULL, NULL);
+  SetForegroundWindow(hwnd);
+  return hwnd;
+}
+
+COLORREF ColorToRef(RgbaColor color) {
+  // Windows device context does not support alpha.
+  return RGB(color.red, color.green, color.blue);
+}
+
+// A ScreenDrawer implementation for Windows.
+class ScreenDrawerWin : public ScreenDrawer {
+ public:
+  ScreenDrawerWin();
+  ~ScreenDrawerWin() override;
+
+  // ScreenDrawer interface.
+  DesktopRect DrawableRegion() override;
+  void DrawRectangle(DesktopRect rect, RgbaColor color) override;
+  void Clear() override;
+  void WaitForPendingDraws() override;
+  bool MayDrawIncompleteShapes() override;
+  WindowId window_id() const override;
+
+ private:
+  // Bring the window to the front, this can help to avoid the impact from other
+  // windows or shadow effects.
+  void BringToFront();
+
+  // Draw a line with `color`.
+  void DrawLine(DesktopVector start, DesktopVector end, RgbaColor color);
+
+  // Draw a dot with `color`.
+  void DrawDot(DesktopVector vect, RgbaColor color);
+
+  const DesktopRect rect_;
+  HWND window_;
+  HDC hdc_;
+};
+
+ScreenDrawerWin::ScreenDrawerWin()
+    : ScreenDrawer(),
+      rect_(GetScreenRect()),
+      window_(CreateDrawerWindow(rect_)),
+      hdc_(GetWindowDC(window_)) {
+  // We do not need to handle any messages for the `window_`, so disable Windows
+  // from processing windows ghosting feature.
+  DisableProcessWindowsGhosting();
+
+  // Always use stock pen (DC_PEN) and brush (DC_BRUSH).
+  SelectObject(hdc_, GetStockObject(DC_PEN));
+  SelectObject(hdc_, GetStockObject(DC_BRUSH));
+  BringToFront();
+}
+
+ScreenDrawerWin::~ScreenDrawerWin() {
+  ReleaseDC(NULL, hdc_);
+  DestroyWindow(window_);
+  // Unfortunately there is no EnableProcessWindowsGhosting() API.
+}
+
+DesktopRect ScreenDrawerWin::DrawableRegion() {
+  return rect_;
+}
+
+void ScreenDrawerWin::DrawRectangle(DesktopRect rect, RgbaColor color) {
+  if (rect.width() == 1 && rect.height() == 1) {
+    // Rectangle function cannot draw a 1 pixel rectangle.
+    DrawDot(rect.top_left(), color);
+    return;
+  }
+
+  if (rect.width() == 1 || rect.height() == 1) {
+    // Rectangle function cannot draw a 1 pixel rectangle.
+    DrawLine(rect.top_left(), DesktopVector(rect.right(), rect.bottom()),
+             color);
+    return;
+  }
+
+  SetDCBrushColor(hdc_, ColorToRef(color));
+  SetDCPenColor(hdc_, ColorToRef(color));
+  Rectangle(hdc_, rect.left(), rect.top(), rect.right(), rect.bottom());
+}
+
+void ScreenDrawerWin::Clear() {
+  DrawRectangle(rect_, RgbaColor(0, 0, 0));
+}
+
+// TODO(zijiehe): Find the right signal to indicate the finish of all pending
+// paintings.
+void ScreenDrawerWin::WaitForPendingDraws() {
+  BringToFront();
+  SleepMs(50);
+}
+
+bool ScreenDrawerWin::MayDrawIncompleteShapes() {
+  return true;
+}
+
+WindowId ScreenDrawerWin::window_id() const {
+  return reinterpret_cast<WindowId>(window_);
+}
+
+void ScreenDrawerWin::DrawLine(DesktopVector start,
+                               DesktopVector end,
+                               RgbaColor color) {
+  POINT points[2];
+  points[0].x = start.x();
+  points[0].y = start.y();
+  points[1].x = end.x();
+  points[1].y = end.y();
+  SetDCPenColor(hdc_, ColorToRef(color));
+  Polyline(hdc_, points, 2);
+}
+
+void ScreenDrawerWin::DrawDot(DesktopVector vect, RgbaColor color) {
+  SetPixel(hdc_, vect.x(), vect.y(), ColorToRef(color));
+}
+
+void ScreenDrawerWin::BringToFront() {
+  if (SetWindowPos(window_, HWND_TOPMOST, 0, 0, 0, 0,
+                   SWP_NOMOVE | SWP_NOSIZE) != FALSE) {
+    return;
+  }
+
+  long ex_style = GetWindowLong(window_, GWL_EXSTYLE);
+  ex_style |= WS_EX_TOPMOST;
+  if (SetWindowLong(window_, GWL_EXSTYLE, ex_style) != 0) {
+    return;
+  }
+
+  BringWindowToTop(window_);
+}
+
+}  // namespace
+
+// static
+std::unique_ptr<ScreenDrawerLock> ScreenDrawerLock::Create() {
+  return std::unique_ptr<ScreenDrawerLock>(new ScreenDrawerLockWin());
+}
+
+// static
+std::unique_ptr<ScreenDrawer> ScreenDrawer::Create() {
+  return std::unique_ptr<ScreenDrawer>(new ScreenDrawerWin());
+}
+
+}  // namespace webrtc