widget/WindowSurface.h

   1 /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*-
   2  *
   3  * This Source Code Form is subject to the terms of the Mozilla Public
   4  * License, v. 2.0. If a copy of the MPL was not distributed with this
   5  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   6
   7 #ifndef _MOZILLA_WIDGET_WINDOW_SURFACE_H
   8 #define _MOZILLA_WIDGET_WINDOW_SURFACE_H
   9
  10 #include "mozilla/gfx/2D.h"
  11 #include "Units.h"
  12
  13 namespace mozilla {
  14 namespace widget {
  15
  16 // A class for drawing to double-buffered windows.
  17 class WindowSurface {
  18  public:
  19   virtual ~WindowSurface() = default;
  20
  21   // Locks a region of the window for drawing, returning a draw target
  22   // capturing the bounds of the provided region.
  23   // Implementations must permit invocation from any thread.
  24   virtual already_AddRefed<gfx::DrawTarget> Lock(
  25       const LayoutDeviceIntRegion& aRegion) = 0;
  26
  27   // Swaps the provided invalid region from the back buffer to the window.
  28   // Implementations must permit invocation from any thread.
  29   virtual void Commit(const LayoutDeviceIntRegion& aInvalidRegion) = 0;
  30
  31   // Whether the window surface represents a fallback method.
  32   virtual bool IsFallback() const { return false; }
  33 };
  34
  35 }  // namespace widget
  36 }  // namespace mozilla
  37
  38 #endif  // _MOZILLA_WIDGET_WINDOW_SURFACE_H