contents_scaling_layer.cc revision 6e8cce623b6e4fe0c9e4af605d675dd9d0338c38 
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#include "cc/layers/contents_scaling_layer.h"
6#include "ui/gfx/size_conversions.h"
7
8namespace cc {
9
10gfx::Size ContentsScalingLayer::ComputeContentBoundsForScale(
11    float scale_x,
12    float scale_y) const {
13  return gfx::ToCeiledSize(gfx::ScaleSize(bounds(), scale_x, scale_y));
14}
15
16ContentsScalingLayer::ContentsScalingLayer()
17    : last_update_contents_scale_x_(0.f),
18      last_update_contents_scale_y_(0.f) {}
19
20ContentsScalingLayer::~ContentsScalingLayer() {
21}
22
23void ContentsScalingLayer::CalculateContentsScale(
24    float ideal_contents_scale,
25    float* contents_scale_x,
26    float* contents_scale_y,
27    gfx::Size* content_bounds) {
28  *contents_scale_x = ideal_contents_scale;
29  *contents_scale_y = ideal_contents_scale;
30  *content_bounds = ComputeContentBoundsForScale(
31      ideal_contents_scale,
32      ideal_contents_scale);
33}
34
35bool ContentsScalingLayer::Update(ResourceUpdateQueue* queue,
36                                  const OcclusionTracker<Layer>* occlusion) {
37  bool updated = Layer::Update(queue, occlusion);
38
39  if (draw_properties().contents_scale_x == last_update_contents_scale_x_ &&
40      draw_properties().contents_scale_y == last_update_contents_scale_y_)
41    return updated;
42
43  last_update_contents_scale_x_ = draw_properties().contents_scale_x;
44  last_update_contents_scale_y_ = draw_properties().contents_scale_y;
45  // Invalidate the whole layer if scale changed.
46  SetNeedsDisplayRect(gfx::Rect(paint_properties().bounds));
47  return updated;
48}
49
50}  // namespace cc
51