ui/compositor/compositing_recorder.h

   1 // Copyright 2015 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_COMPOSITOR_COMPOSITING_RECORDER_H_
   6 #define UI_COMPOSITOR_COMPOSITING_RECORDER_H_
   7
   8 #include "base/basictypes.h"
   9 #include "base/macros.h"
  10 #include "ui/compositor/compositor_export.h"
  11
  12 namespace gfx {
  13 class Canvas;
  14 }
  15
  16 namespace ui {
  17 class PaintContext;
  18
  19 // A class to provide scoped compositing filters (eg opacity) of painting to a
  20 // DisplayItemList. The filters provided will be applied to any
  21 // DisplayItems added to the DisplayItemList while this object is alive. In
  22 // other words, any nested PaintRecorders or other such Recorders will
  23 // be filtered by the effect.
  24 class COMPOSITOR_EXPORT CompositingRecorder {
  25  public:
  26   // |alpha| is a value between 0 and 255, where 0 is transparent and 255 is
  27   // opaque.
  28   CompositingRecorder(const PaintContext& context, uint8_t alpha);
  29   ~CompositingRecorder();
  30
  31  private:
  32   gfx::Canvas* canvas_;
  33   bool saved_;
  34
  35   DISALLOW_COPY_AND_ASSIGN(CompositingRecorder);
  36 };
  37
  38 }  // namespace ui
  39
  40 #endif  // UI_COMPOSITOR_CLIP_TRANSFORM_RECORDER_H_