contents_scaling_layer.h revision b2df76ea8fec9e32f6f3718986dba0d95315b29c 
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 void Update(
27    ResourceUpdateQueue* queue,
28    const OcclusionTracker* occlusion,
29    RenderingStats* stats) OVERRIDE;
30
31 protected:
32  ContentsScalingLayer();
33  virtual ~ContentsScalingLayer();
34
35  gfx::Size ComputeContentBoundsForScale(float scale_x, float scale_y) const;
36
37 private:
38  float last_update_contents_scale_x_;
39  float last_update_contents_scale_y_;
40
41  DISALLOW_COPY_AND_ASSIGN(ContentsScalingLayer);
42};
43
44}  // namespace cc
45
46#endif  // CC_LAYERS_CONTENTS_SCALING_LAYER_H__
47