ui/gfx/scoped_canvas.h

   1 // Copyright 2013 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #ifndef UI_GFX_SCOPED_CANVAS_H_
   6 #define UI_GFX_SCOPED_CANVAS_H_
   7
   8 #include "ui/gfx/canvas.h"
   9
  10 namespace gfx {
  11
  12 // Saves the drawing state, and restores the state when going out of scope.
  13 class ScopedCanvas {
  14  public:
  15   explicit ScopedCanvas(gfx::Canvas* canvas) : canvas_(canvas) {
  16     if (canvas_)
  17       canvas_->Save();
  18   }
  19   ~ScopedCanvas() {
  20     if (canvas_)
  21       canvas_->Restore();
  22   }
  23   void SetCanvas(gfx::Canvas* canvas) {
  24     if (canvas_)
  25       canvas_->Restore();
  26     canvas_ = canvas;
  27     canvas_->Save();
  28   }
  29
  30  private:
  31   gfx::Canvas* canvas_;
  32
  33   DISALLOW_COPY_AND_ASSIGN(ScopedCanvas);
  34 };
  35
  36 }  // namespace gfx
  37
  38 #endif  // UI_GFX_SCOPED_CANVAS_H_