cc/layers/contents_scaling_layer.cc

   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 "cc/trees/layer_tree_host.h"
   7 #include "ui/gfx/geometry/size_conversions.h"
   8
   9 namespace cc {
  10
  11 gfx::Size ContentsScalingLayer::ComputeContentBoundsForScale(
  12     float scale_x,
  13     float scale_y) const {
  14   return gfx::ToCeiledSize(gfx::ScaleSize(bounds(), scale_x, scale_y));
  15 }
  16
  17 ContentsScalingLayer::ContentsScalingLayer(const LayerSettings& settings)
  18     : Layer(settings),
  19       last_update_contents_scale_x_(0.f),
  20       last_update_contents_scale_y_(0.f) {
  21 }
  22
  23 ContentsScalingLayer::~ContentsScalingLayer() {
  24 }
  25
  26 void ContentsScalingLayer::CalculateContentsScale(
  27     float ideal_contents_scale,
  28     float* contents_scale_x,
  29     float* contents_scale_y,
  30     gfx::Size* content_bounds) {
  31   float old_contents_scale_x = *contents_scale_x;
  32   float old_contents_scale_y = *contents_scale_y;
  33   gfx::Size old_content_bounds = *content_bounds;
  34   *contents_scale_x = ideal_contents_scale;
  35   *contents_scale_y = ideal_contents_scale;
  36   *content_bounds = ComputeContentBoundsForScale(
  37       ideal_contents_scale,
  38       ideal_contents_scale);
  39
  40   if (!layer_tree_host())
  41     return;
  42
  43   if (old_contents_scale_x != *contents_scale_x ||
  44       old_contents_scale_y != *contents_scale_y ||
  45       old_content_bounds != *content_bounds) {
  46     layer_tree_host()->property_trees()->needs_rebuild = true;
  47   }
  48 }
  49
  50 bool ContentsScalingLayer::Update(ResourceUpdateQueue* queue,
  51                                   const OcclusionTracker<Layer>* occlusion) {
  52   bool updated = Layer::Update(queue, occlusion);
  53
  54   if (draw_properties().contents_scale_x == last_update_contents_scale_x_ &&
  55       draw_properties().contents_scale_y == last_update_contents_scale_y_)
  56     return updated;
  57
  58   last_update_contents_scale_x_ = draw_properties().contents_scale_x;
  59   last_update_contents_scale_y_ = draw_properties().contents_scale_y;
  60   // Invalidate the whole layer if scale changed.
  61   SetNeedsDisplayRect(gfx::Rect(paint_properties().bounds));
  62   return updated;
  63 }
  64
  65 }  // namespace cc