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      1 // Copyright 2010 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/image_layer.h"
      6 
      7 #include "base/compiler_specific.h"
      8 #include "cc/resources/image_layer_updater.h"
      9 #include "cc/resources/layer_updater.h"
     10 #include "cc/resources/prioritized_resource.h"
     11 #include "cc/resources/resource_update_queue.h"
     12 #include "cc/trees/layer_tree_host.h"
     13 
     14 namespace cc {
     15 
     16 scoped_refptr<ImageLayer> ImageLayer::Create() {
     17   return make_scoped_refptr(new ImageLayer());
     18 }
     19 
     20 ImageLayer::ImageLayer() : TiledLayer() {}
     21 
     22 ImageLayer::~ImageLayer() {}
     23 
     24 void ImageLayer::SetBitmap(const SkBitmap& bitmap) {
     25   // SetBitmap() currently gets called whenever there is any
     26   // style change that affects the layer even if that change doesn't
     27   // affect the actual contents of the image (e.g. a CSS animation).
     28   // With this check in place we avoid unecessary texture uploads.
     29   if (bitmap.pixelRef() && bitmap.pixelRef() == bitmap_.pixelRef())
     30     return;
     31 
     32   bitmap_ = bitmap;
     33   SetNeedsDisplay();
     34 }
     35 
     36 void ImageLayer::SetTexturePriorities(const PriorityCalculator& priority_calc) {
     37   // Update the tile data before creating all the layer's tiles.
     38   UpdateTileSizeAndTilingOption();
     39 
     40   TiledLayer::SetTexturePriorities(priority_calc);
     41 }
     42 
     43 bool ImageLayer::Update(ResourceUpdateQueue* queue,
     44                         const OcclusionTracker* occlusion) {
     45   CreateUpdaterIfNeeded();
     46   if (!updater_->UsingBitmap(bitmap_)) {
     47     updater_->SetBitmap(bitmap_);
     48     UpdateTileSizeAndTilingOption();
     49     InvalidateContentRect(gfx::Rect(content_bounds()));
     50   }
     51   return TiledLayer::Update(queue, occlusion);
     52 }
     53 
     54 void ImageLayer::CreateUpdaterIfNeeded() {
     55   if (updater_.get())
     56     return;
     57 
     58   updater_ = ImageLayerUpdater::Create();
     59   SetTextureFormat(
     60       layer_tree_host()->GetRendererCapabilities().best_texture_format);
     61 }
     62 
     63 LayerUpdater* ImageLayer::Updater() const {
     64   return updater_.get();
     65 }
     66 
     67 void ImageLayer::CalculateContentsScale(float ideal_contents_scale,
     68                                         float device_scale_factor,
     69                                         float page_scale_factor,
     70                                         bool animating_transform_to_screen,
     71                                         float* contents_scale_x,
     72                                         float* contents_scale_y,
     73                                         gfx::Size* content_bounds) {
     74   *contents_scale_x = ImageContentsScaleX();
     75   *contents_scale_y = ImageContentsScaleY();
     76   *content_bounds = gfx::Size(bitmap_.width(), bitmap_.height());
     77 }
     78 
     79 bool ImageLayer::DrawsContent() const {
     80   return !bitmap_.isNull() && TiledLayer::DrawsContent();
     81 }
     82 
     83 void ImageLayer::OnOutputSurfaceCreated() {
     84   SetTextureFormat(
     85       layer_tree_host()->GetRendererCapabilities().best_texture_format);
     86   TiledLayer::OnOutputSurfaceCreated();
     87 }
     88 
     89 float ImageLayer::ImageContentsScaleX() const {
     90   if (bounds().IsEmpty() || bitmap_.width() == 0)
     91     return 1;
     92   return static_cast<float>(bitmap_.width()) / bounds().width();
     93 }
     94 
     95 float ImageLayer::ImageContentsScaleY() const {
     96   if (bounds().IsEmpty() || bitmap_.height() == 0)
     97     return 1;
     98   return static_cast<float>(bitmap_.height()) / bounds().height();
     99 }
    100 
    101 }  // namespace cc
    102