/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*-

 *

 * This Source Code Form is subject to the terms of the Mozilla Public

 * License, v. 2.0. If a copy of the MPL was not distributed with this

 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#ifndef _MOZILLA_WIDGET_WINDOW_SURFACE_H

#define _MOZILLA_WIDGET_WINDOW_SURFACE_H

#include "mozilla/gfx/2D.h"

#include "Units.h"

namespace mozilla {

namespace widget {

// A class for drawing to double-buffered windows.

class WindowSurface {

public:

  virtual ~WindowSurface() {}

  // Locks a region of the window for drawing, returning a draw target

  // capturing the bounds of the provided region.

  // Implementations must permit invocation from any thread.

  virtual already_AddRefed<gfx::DrawTarget> Lock(const LayoutDeviceIntRegion& aRegion) = 0;

  // Swaps the provided invalid region from the back buffer to the window.

  // Implementations must permit invocation from any thread.

  virtual void Commit(const LayoutDeviceIntRegion& aInvalidRegion) = 0;

  // Whether the window surface represents a fallback method.

  virtual bool IsFallback() const { return false; }

};

}  // namespace widget

}  // namespace mozilla

#endif // _MOZILLA_WIDGET_WINDOW_SURFACE_H