src/cc/trees/tree_synchronizer.cc

   1 // Copyright 2011 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/trees/tree_synchronizer.h"
   6
   7 #include "base/containers/hash_tables.h"
   8 #include "base/containers/scoped_ptr_hash_map.h"
   9 #include "base/debug/trace_event.h"
  10 #include "base/logging.h"
  11 #include "cc/animation/scrollbar_animation_controller.h"
  12 #include "cc/input/scrollbar.h"
  13 #include "cc/layers/layer.h"
  14 #include "cc/layers/layer_impl.h"
  15 #include "cc/layers/scrollbar_layer_impl_base.h"
  16 #include "cc/layers/scrollbar_layer_interface.h"
  17
  18 namespace cc {
  19
  20 typedef base::ScopedPtrHashMap<int, LayerImpl> ScopedPtrLayerImplMap;
  21 typedef base::hash_map<int, LayerImpl*> RawPtrLayerImplMap;
  22
  23 void CollectExistingLayerImplRecursive(ScopedPtrLayerImplMap* old_layers,
  24                                        scoped_ptr<LayerImpl> layer_impl) {
  25   if (!layer_impl)
  26     return;
  27
  28   OwnedLayerImplList& children = layer_impl->children();
  29   for (OwnedLayerImplList::iterator it = children.begin();
  30        it != children.end();
  31        ++it)
  32     CollectExistingLayerImplRecursive(old_layers, children.take(it));
  33
  34   CollectExistingLayerImplRecursive(old_layers, layer_impl->TakeMaskLayer());
  35   CollectExistingLayerImplRecursive(old_layers, layer_impl->TakeReplicaLayer());
  36
  37   int id = layer_impl->id();
  38   old_layers->set(id, layer_impl.Pass());
  39 }
  40
  41 template <typename LayerType>
  42 scoped_ptr<LayerImpl> SynchronizeTreesInternal(
  43     LayerType* layer_root,
  44     scoped_ptr<LayerImpl> old_layer_impl_root,
  45     LayerTreeImpl* tree_impl) {
  46   DCHECK(tree_impl);
  47
  48   TRACE_EVENT0("cc", "TreeSynchronizer::SynchronizeTrees");
  49   ScopedPtrLayerImplMap old_layers;
  50   RawPtrLayerImplMap new_layers;
  51
  52   CollectExistingLayerImplRecursive(&old_layers, old_layer_impl_root.Pass());
  53
  54   scoped_ptr<LayerImpl> new_tree = SynchronizeTreesRecursive(
  55       &new_layers, &old_layers, layer_root, tree_impl);
  56
  57   UpdateScrollbarLayerPointersRecursive(&new_layers, layer_root);
  58
  59   return new_tree.Pass();
  60 }
  61
  62 scoped_ptr<LayerImpl> TreeSynchronizer::SynchronizeTrees(
  63     Layer* layer_root,
  64     scoped_ptr<LayerImpl> old_layer_impl_root,
  65     LayerTreeImpl* tree_impl) {
  66   return SynchronizeTreesInternal(
  67       layer_root, old_layer_impl_root.Pass(), tree_impl);
  68 }
  69
  70 scoped_ptr<LayerImpl> TreeSynchronizer::SynchronizeTrees(
  71     LayerImpl* layer_root,
  72     scoped_ptr<LayerImpl> old_layer_impl_root,
  73     LayerTreeImpl* tree_impl) {
  74   return SynchronizeTreesInternal(
  75       layer_root, old_layer_impl_root.Pass(), tree_impl);
  76 }
  77
  78 template <typename LayerType>
  79 scoped_ptr<LayerImpl> ReuseOrCreateLayerImpl(RawPtrLayerImplMap* new_layers,
  80                                              ScopedPtrLayerImplMap* old_layers,
  81                                              LayerType* layer,
  82                                              LayerTreeImpl* tree_impl) {
  83   scoped_ptr<LayerImpl> layer_impl = old_layers->take(layer->id());
  84
  85   if (!layer_impl)
  86     layer_impl = layer->CreateLayerImpl(tree_impl);
  87
  88   (*new_layers)[layer->id()] = layer_impl.get();
  89   return layer_impl.Pass();
  90 }
  91
  92 template <typename LayerType>
  93 scoped_ptr<LayerImpl> SynchronizeTreesRecursiveInternal(
  94     RawPtrLayerImplMap* new_layers,
  95     ScopedPtrLayerImplMap* old_layers,
  96     LayerType* layer,
  97     LayerTreeImpl* tree_impl) {
  98   if (!layer)
  99     return scoped_ptr<LayerImpl>();
 100
 101   scoped_ptr<LayerImpl> layer_impl =
 102       ReuseOrCreateLayerImpl(new_layers, old_layers, layer, tree_impl);
 103
 104   layer_impl->ClearChildList();
 105   for (size_t i = 0; i < layer->children().size(); ++i) {
 106     layer_impl->AddChild(SynchronizeTreesRecursiveInternal(
 107         new_layers, old_layers, layer->child_at(i), tree_impl));
 108   }
 109
 110   layer_impl->SetMaskLayer(SynchronizeTreesRecursiveInternal(
 111       new_layers, old_layers, layer->mask_layer(), tree_impl));
 112   layer_impl->SetReplicaLayer(SynchronizeTreesRecursiveInternal(
 113       new_layers, old_layers, layer->replica_layer(), tree_impl));
 114
 115   // Remove all dangling pointers. The pointers will be setup later in
 116   // UpdateScrollbarLayerPointersRecursive phase
 117   layer_impl->SetHorizontalScrollbarLayer(NULL);
 118   layer_impl->SetVerticalScrollbarLayer(NULL);
 119
 120   return layer_impl.Pass();
 121 }
 122
 123 scoped_ptr<LayerImpl> SynchronizeTreesRecursive(
 124     RawPtrLayerImplMap* new_layers,
 125     ScopedPtrLayerImplMap* old_layers,
 126     Layer* layer,
 127     LayerTreeImpl* tree_impl) {
 128   return SynchronizeTreesRecursiveInternal(
 129       new_layers, old_layers, layer, tree_impl);
 130 }
 131
 132 scoped_ptr<LayerImpl> SynchronizeTreesRecursive(
 133     RawPtrLayerImplMap* new_layers,
 134     ScopedPtrLayerImplMap* old_layers,
 135     LayerImpl* layer,
 136     LayerTreeImpl* tree_impl) {
 137   return SynchronizeTreesRecursiveInternal(
 138       new_layers, old_layers, layer, tree_impl);
 139 }
 140
 141 template <typename LayerType, typename ScrollbarLayerType>
 142 void UpdateScrollbarLayerPointersRecursiveInternal(
 143     const RawPtrLayerImplMap* new_layers,
 144     LayerType* layer) {
 145   if (!layer)
 146     return;
 147
 148   for (size_t i = 0; i < layer->children().size(); ++i) {
 149     UpdateScrollbarLayerPointersRecursiveInternal<
 150         LayerType, ScrollbarLayerType>(new_layers, layer->child_at(i));
 151   }
 152
 153   ScrollbarLayerType* scrollbar_layer = layer->ToScrollbarLayer();
 154   if (!scrollbar_layer)
 155     return;
 156
 157   RawPtrLayerImplMap::const_iterator iter =
 158       new_layers->find(layer->id());
 159   ScrollbarLayerImplBase* scrollbar_layer_impl =
 160       iter != new_layers->end()
 161           ? static_cast<ScrollbarLayerImplBase*>(iter->second)
 162           : NULL;
 163   iter = new_layers->find(scrollbar_layer->ScrollLayerId());
 164   LayerImpl* scroll_layer_impl =
 165       iter != new_layers->end() ? iter->second : NULL;
 166
 167   DCHECK(scrollbar_layer_impl);
 168   DCHECK(scroll_layer_impl);
 169
 170   if (scrollbar_layer->orientation() == HORIZONTAL)
 171     scroll_layer_impl->SetHorizontalScrollbarLayer(scrollbar_layer_impl);
 172   else
 173     scroll_layer_impl->SetVerticalScrollbarLayer(scrollbar_layer_impl);
 174 }
 175
 176 void UpdateScrollbarLayerPointersRecursive(const RawPtrLayerImplMap* new_layers,
 177                                            Layer* layer) {
 178   UpdateScrollbarLayerPointersRecursiveInternal<Layer, ScrollbarLayerInterface>(
 179       new_layers, layer);
 180 }
 181
 182 void UpdateScrollbarLayerPointersRecursive(const RawPtrLayerImplMap* new_layers,
 183                                            LayerImpl* layer) {
 184   UpdateScrollbarLayerPointersRecursiveInternal<
 185       LayerImpl,
 186       ScrollbarLayerImplBase>(new_layers, layer);
 187 }
 188
 189 // static
 190 void TreeSynchronizer::SetNumDependentsNeedPushProperties(
 191     Layer* layer, size_t num) {
 192   layer->num_dependents_need_push_properties_ = num;
 193 }
 194
 195 // static
 196 void TreeSynchronizer::SetNumDependentsNeedPushProperties(
 197     LayerImpl* layer, size_t num) {
 198 }
 199
 200 // static
 201 template <typename LayerType>
 202 void TreeSynchronizer::PushPropertiesInternal(
 203     LayerType* layer,
 204     LayerImpl* layer_impl,
 205     size_t* num_dependents_need_push_properties_for_parent) {
 206   if (!layer) {
 207     DCHECK(!layer_impl);
 208     return;
 209   }
 210
 211   DCHECK_EQ(layer->id(), layer_impl->id());
 212
 213   bool push_layer = layer->needs_push_properties();
 214   bool recurse_on_children_and_dependents =
 215       layer->descendant_needs_push_properties();
 216
 217   if (push_layer)
 218     layer->PushPropertiesTo(layer_impl);
 219
 220   size_t num_dependents_need_push_properties = 0;
 221   if (recurse_on_children_and_dependents) {
 222     PushPropertiesInternal(layer->mask_layer(),
 223                            layer_impl->mask_layer(),
 224                            &num_dependents_need_push_properties);
 225     PushPropertiesInternal(layer->replica_layer(),
 226                            layer_impl->replica_layer(),
 227                            &num_dependents_need_push_properties);
 228
 229     const OwnedLayerImplList& impl_children = layer_impl->children();
 230     DCHECK_EQ(layer->children().size(), impl_children.size());
 231
 232     for (size_t i = 0; i < layer->children().size(); ++i) {
 233       PushPropertiesInternal(layer->child_at(i),
 234                              impl_children[i],
 235                              &num_dependents_need_push_properties);
 236     }
 237
 238     // When PushPropertiesTo completes for a layer, it may still keep
 239     // its needs_push_properties() state if the layer must push itself
 240     // every PushProperties tree walk. Here we keep track of those layers, and
 241     // ensure that their ancestors know about them for the next PushProperties
 242     // tree walk.
 243     SetNumDependentsNeedPushProperties(
 244         layer, num_dependents_need_push_properties);
 245   }
 246
 247   bool add_self_to_parent = num_dependents_need_push_properties > 0 ||
 248                             layer->needs_push_properties();
 249   *num_dependents_need_push_properties_for_parent += add_self_to_parent ? 1 : 0;
 250 }
 251
 252 void TreeSynchronizer::PushProperties(Layer* layer,
 253                                       LayerImpl* layer_impl) {
 254   size_t num_dependents_need_push_properties = 0;
 255   PushPropertiesInternal(
 256       layer, layer_impl, &num_dependents_need_push_properties);
 257 }
 258
 259 void TreeSynchronizer::PushProperties(LayerImpl* layer, LayerImpl* layer_impl) {
 260   size_t num_dependents_need_push_properties = 0;
 261   PushPropertiesInternal(
 262       layer, layer_impl, &num_dependents_need_push_properties);
 263 }
 264
 265 }  // namespace cc