ui/compositor/paint_cache.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_PAINT_CACHE_H_
   6 #define UI_COMPOSITOR_PAINT_CACHE_H_
   7
   8 #include "cc/resources/drawing_display_item.h"
   9 #include "ui/compositor/compositor_export.h"
  10
  11 namespace ui {
  12 class PaintContext;
  13 class PaintRecorder;
  14
  15 // A class that holds the output of a PaintRecorder to be reused when the
  16 // object that created the PaintRecorder has not been changed/invalidated.
  17 class COMPOSITOR_EXPORT PaintCache {
  18  public:
  19   PaintCache();
  20   ~PaintCache();
  21
  22   // Returns true if the PaintCache was able to insert a previously-saved
  23   // painting output into the PaintContext. If it returns false, the caller
  24   // needs to do the work of painting, which can be stored into the PaintCache
  25   // to be used next time.
  26   bool UseCache(const PaintContext& context);
  27
  28  private:
  29   // Only PaintRecorder can modify these.
  30   friend PaintRecorder;
  31
  32   void SetCache(const cc::DrawingDisplayItem* item);
  33
  34   bool has_cache_;
  35   cc::DrawingDisplayItem display_item_;
  36
  37   DISALLOW_COPY_AND_ASSIGN(PaintCache);
  38 };
  39
  40 }  // namespace ui
  41
  42 #endif  // UI_COMPOSITOR_PAINT_CACHE_H_