contents_scaling_layer.h revision a1401311d1ab56c4ed0a474bd38c108f75cb0cd9 
1// Copyright 2012 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 CC_LAYERS_CONTENTS_SCALING_LAYER_H_
6#define CC_LAYERS_CONTENTS_SCALING_LAYER_H_
7
8#include "cc/base/cc_export.h"
9#include "cc/layers/layer.h"
10
11namespace cc {
12
13// Base class for layers that need contents scale.
14// The content bounds are determined by bounds and scale of the contents.
15class CC_EXPORT ContentsScalingLayer : public Layer {
16 public:
17  virtual void CalculateContentsScale(
18      float ideal_contents_scale,
19      float device_scale_factor,
20      float page_scale_factor,
21      bool animating_transform_to_screen,
22      float* contents_scale_x,
23      float* contents_scale_y,
24      gfx::Size* content_bounds) OVERRIDE;
25
26  virtual bool Update(ResourceUpdateQueue* queue,
27                      const OcclusionTracker<Layer>* occlusion) OVERRIDE;
28
29 protected:
30  ContentsScalingLayer();
31  virtual ~ContentsScalingLayer();
32
33  gfx::Size ComputeContentBoundsForScale(float scale_x, float scale_y) const;
34
35 private:
36  float last_update_contents_scale_x_;
37  float last_update_contents_scale_y_;
38
39  DISALLOW_COPY_AND_ASSIGN(ContentsScalingLayer);
40};
41
42}  // namespace cc
43
44#endif  // CC_LAYERS_CONTENTS_SCALING_LAYER_H__
45