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