1 files changed, 185 insertions, 0 deletions
diff --git a/third_party/libwebrtc/modules/desktop_capture/screen_drawer_linux.cc b/third_party/libwebrtc/modules/desktop_capture/screen_drawer_linux.cc
new file mode 100644
index 0000000000..fce036b4aa
--- /dev/null
+++ b/third_party/libwebrtc/modules/desktop_capture/screen_drawer_linux.cc
@@ -0,0 +1,185 @@
+/*
+ *  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 <X11/X.h>
+#include <X11/Xlib.h>
+#include <string.h>
+
+#include <memory>
+
+#include "api/scoped_refptr.h"
+#include "modules/desktop_capture/desktop_capture_types.h"
+#include "modules/desktop_capture/desktop_geometry.h"
+#include "modules/desktop_capture/linux/x11/shared_x_display.h"
+#include "modules/desktop_capture/rgba_color.h"
+#include "modules/desktop_capture/screen_drawer.h"
+#include "modules/desktop_capture/screen_drawer_lock_posix.h"
+#include "rtc_base/checks.h"
+#include "system_wrappers/include/sleep.h"
+
+namespace webrtc {
+
+namespace {
+
+// A ScreenDrawer implementation for X11.
+class ScreenDrawerLinux : public ScreenDrawer {
+ public:
+  ScreenDrawerLinux();
+  ~ScreenDrawerLinux() 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 effect.
+  void BringToFront();
+
+  rtc::scoped_refptr<SharedXDisplay> display_;
+  int screen_num_;
+  DesktopRect rect_;
+  Window window_;
+  GC context_;
+  Colormap colormap_;
+};
+
+ScreenDrawerLinux::ScreenDrawerLinux() {
+  display_ = SharedXDisplay::CreateDefault();
+  RTC_CHECK(display_.get());
+  screen_num_ = DefaultScreen(display_->display());
+  XWindowAttributes root_attributes;
+  if (!XGetWindowAttributes(display_->display(),
+                            RootWindow(display_->display(), screen_num_),
+                            &root_attributes)) {
+    RTC_DCHECK_NOTREACHED() << "Failed to get root window size.";
+  }
+  window_ = XCreateSimpleWindow(
+      display_->display(), RootWindow(display_->display(), screen_num_), 0, 0,
+      root_attributes.width, root_attributes.height, 0,
+      BlackPixel(display_->display(), screen_num_),
+      BlackPixel(display_->display(), screen_num_));
+  XSelectInput(display_->display(), window_, StructureNotifyMask);
+  XMapWindow(display_->display(), window_);
+  while (true) {
+    XEvent event;
+    XNextEvent(display_->display(), &event);
+    if (event.type == MapNotify) {
+      break;
+    }
+  }
+  XFlush(display_->display());
+  Window child;
+  int x, y;
+  if (!XTranslateCoordinates(display_->display(), window_,
+                             RootWindow(display_->display(), screen_num_), 0, 0,
+                             &x, &y, &child)) {
+    RTC_DCHECK_NOTREACHED() << "Failed to get window position.";
+  }
+  // Some window manager does not allow a window to cover two or more monitors.
+  // So if the window is on the first monitor of a two-monitor system, the
+  // second half won't be able to show up without changing configurations of WM,
+  // and its DrawableRegion() is not accurate.
+  rect_ = DesktopRect::MakeLTRB(x, y, root_attributes.width,
+                                root_attributes.height);
+  context_ = DefaultGC(display_->display(), screen_num_);
+  colormap_ = DefaultColormap(display_->display(), screen_num_);
+  BringToFront();
+  // Wait for window animations.
+  SleepMs(200);
+}
+
+ScreenDrawerLinux::~ScreenDrawerLinux() {
+  XUnmapWindow(display_->display(), window_);
+  XDestroyWindow(display_->display(), window_);
+}
+
+DesktopRect ScreenDrawerLinux::DrawableRegion() {
+  return rect_;
+}
+
+void ScreenDrawerLinux::DrawRectangle(DesktopRect rect, RgbaColor color) {
+  rect.Translate(-rect_.left(), -rect_.top());
+  XColor xcolor;
+  // X11 does not support Alpha.
+  // X11 uses 16 bits for each primary color, so we need to slightly normalize
+  // a 8 bits channel to 16 bits channel, by setting the low 8 bits as its high
+  // 8 bits to avoid a mismatch of color returned by capturer.
+  xcolor.red = (color.red << 8) + color.red;
+  xcolor.green = (color.green << 8) + color.green;
+  xcolor.blue = (color.blue << 8) + color.blue;
+  xcolor.flags = DoRed | DoGreen | DoBlue;
+  XAllocColor(display_->display(), colormap_, &xcolor);
+  XSetForeground(display_->display(), context_, xcolor.pixel);
+  XFillRectangle(display_->display(), window_, context_, rect.left(),
+                 rect.top(), rect.width(), rect.height());
+  XFlush(display_->display());
+}
+
+void ScreenDrawerLinux::Clear() {
+  DrawRectangle(rect_, RgbaColor(0, 0, 0));
+}
+
+// TODO(zijiehe): Find the right signal from X11 to indicate the finish of all
+// pending paintings.
+void ScreenDrawerLinux::WaitForPendingDraws() {
+  SleepMs(50);
+}
+
+bool ScreenDrawerLinux::MayDrawIncompleteShapes() {
+  return true;
+}
+
+WindowId ScreenDrawerLinux::window_id() const {
+  return window_;
+}
+
+void ScreenDrawerLinux::BringToFront() {
+  Atom state_above = XInternAtom(display_->display(), "_NET_WM_STATE_ABOVE", 1);
+  Atom window_state = XInternAtom(display_->display(), "_NET_WM_STATE", 1);
+  if (state_above == None || window_state == None) {
+    // Fallback to use XRaiseWindow, it's not reliable if two windows are both
+    // raise itself to the top.
+    XRaiseWindow(display_->display(), window_);
+    return;
+  }
+
+  XEvent event;
+  memset(&event, 0, sizeof(event));
+  event.type = ClientMessage;
+  event.xclient.window = window_;
+  event.xclient.message_type = window_state;
+  event.xclient.format = 32;
+  event.xclient.data.l[0] = 1;  // _NET_WM_STATE_ADD
+  event.xclient.data.l[1] = state_above;
+  XSendEvent(display_->display(), RootWindow(display_->display(), screen_num_),
+             False, SubstructureRedirectMask | SubstructureNotifyMask, &event);
+}
+
+}  // namespace
+
+// static
+std::unique_ptr<ScreenDrawerLock> ScreenDrawerLock::Create() {
+  return std::make_unique<ScreenDrawerLockPosix>();
+}
+
+// static
+std::unique_ptr<ScreenDrawer> ScreenDrawer::Create() {
+  if (SharedXDisplay::CreateDefault().get()) {
+    return std::make_unique<ScreenDrawerLinux>();
+  }
+  return nullptr;
+}
+
+}  // namespace webrtc