src/cc/trees/layer_tree_impl.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/layer_tree_impl.h"
   6
   7 #include <limits>
   8 #include <set>
   9
  10 #include "base/debug/trace_event.h"
  11 #include "base/debug/trace_event_argument.h"
  12 #include "cc/animation/keyframed_animation_curve.h"
  13 #include "cc/animation/scrollbar_animation_controller.h"
  14 #include "cc/animation/scrollbar_animation_controller_linear_fade.h"
  15 #include "cc/animation/scrollbar_animation_controller_thinning.h"
  16 #include "cc/base/math_util.h"
  17 #include "cc/base/util.h"
  18 #include "cc/debug/devtools_instrumentation.h"
  19 #include "cc/debug/traced_value.h"
  20 #include "cc/input/page_scale_animation.h"
  21 #include "cc/layers/heads_up_display_layer_impl.h"
  22 #include "cc/layers/layer.h"
  23 #include "cc/layers/layer_iterator.h"
  24 #include "cc/layers/render_surface_impl.h"
  25 #include "cc/layers/scrollbar_layer_impl_base.h"
  26 #include "cc/resources/ui_resource_request.h"
  27 #include "cc/trees/layer_tree_host_common.h"
  28 #include "cc/trees/layer_tree_host_impl.h"
  29 #include "cc/trees/occlusion_tracker.h"
  30 #include "ui/gfx/point_conversions.h"
  31 #include "ui/gfx/size_conversions.h"
  32 #include "ui/gfx/vector2d_conversions.h"
  33
  34 namespace cc {
  35
  36 // This class exists to split the LayerScrollOffsetDelegate between the
  37 // InnerViewportScrollLayer and the OuterViewportScrollLayer in a manner
  38 // that never requires the embedder or LayerImpl to know about.
  39 class LayerScrollOffsetDelegateProxy : public LayerImpl::ScrollOffsetDelegate {
  40  public:
  41   LayerScrollOffsetDelegateProxy(LayerImpl* layer,
  42                                  LayerScrollOffsetDelegate* delegate,
  43                                  LayerTreeImpl* layer_tree)
  44       : layer_(layer), delegate_(delegate), layer_tree_impl_(layer_tree) {}
  45   virtual ~LayerScrollOffsetDelegateProxy() {}
  46
  47   gfx::Vector2dF last_set_scroll_offset() const {
  48     return last_set_scroll_offset_;
  49   }
  50
  51   // LayerScrollOffsetDelegate implementation.
  52   virtual void SetTotalScrollOffset(const gfx::Vector2dF& new_offset) OVERRIDE {
  53     last_set_scroll_offset_ = new_offset;
  54     layer_tree_impl_->UpdateScrollOffsetDelegate();
  55   }
  56
  57   virtual gfx::Vector2dF GetTotalScrollOffset() OVERRIDE {
  58     return layer_tree_impl_->GetDelegatedScrollOffset(layer_);
  59   }
  60
  61   virtual bool IsExternalFlingActive() const OVERRIDE {
  62     return delegate_->IsExternalFlingActive();
  63   }
  64
  65  private:
  66   LayerImpl* layer_;
  67   LayerScrollOffsetDelegate* delegate_;
  68   LayerTreeImpl* layer_tree_impl_;
  69   gfx::Vector2dF last_set_scroll_offset_;
  70 };
  71
  72 LayerTreeImpl::LayerTreeImpl(LayerTreeHostImpl* layer_tree_host_impl)
  73     : layer_tree_host_impl_(layer_tree_host_impl),
  74       source_frame_number_(-1),
  75       hud_layer_(0),
  76       currently_scrolling_layer_(NULL),
  77       root_layer_scroll_offset_delegate_(NULL),
  78       background_color_(0),
  79       has_transparent_background_(false),
  80       page_scale_layer_(NULL),
  81       inner_viewport_scroll_layer_(NULL),
  82       outer_viewport_scroll_layer_(NULL),
  83       page_scale_factor_(1),
  84       page_scale_delta_(1),
  85       sent_page_scale_delta_(1),
  86       min_page_scale_factor_(0),
  87       max_page_scale_factor_(0),
  88       scrolling_layer_id_from_previous_tree_(0),
  89       contents_textures_purged_(false),
  90       requires_high_res_to_draw_(false),
  91       viewport_size_invalid_(false),
  92       needs_update_draw_properties_(true),
  93       needs_full_tree_sync_(true),
  94       next_activation_forces_redraw_(false),
  95       has_ever_been_drawn_(false),
  96       render_surface_layer_list_id_(0),
  97       top_controls_layout_height_(0),
  98       top_controls_content_offset_(0),
  99       top_controls_delta_(0),
 100       sent_top_controls_delta_(0) {
 101 }
 102
 103 LayerTreeImpl::~LayerTreeImpl() {
 104   BreakSwapPromises(SwapPromise::SWAP_FAILS);
 105
 106   // Need to explicitly clear the tree prior to destroying this so that
 107   // the LayerTreeImpl pointer is still valid in the LayerImpl dtor.
 108   DCHECK(!root_layer_);
 109   DCHECK(layers_with_copy_output_request_.empty());
 110 }
 111
 112 void LayerTreeImpl::Shutdown() { root_layer_.reset(); }
 113
 114 void LayerTreeImpl::ReleaseResources() {
 115   if (root_layer_)
 116     ReleaseResourcesRecursive(root_layer_.get());
 117 }
 118
 119 void LayerTreeImpl::SetRootLayer(scoped_ptr<LayerImpl> layer) {
 120   if (inner_viewport_scroll_layer_)
 121     inner_viewport_scroll_layer_->SetScrollOffsetDelegate(NULL);
 122   if (outer_viewport_scroll_layer_)
 123     outer_viewport_scroll_layer_->SetScrollOffsetDelegate(NULL);
 124   inner_viewport_scroll_delegate_proxy_.reset();
 125   outer_viewport_scroll_delegate_proxy_.reset();
 126
 127   root_layer_ = layer.Pass();
 128   currently_scrolling_layer_ = NULL;
 129   inner_viewport_scroll_layer_ = NULL;
 130   outer_viewport_scroll_layer_ = NULL;
 131   page_scale_layer_ = NULL;
 132
 133   layer_tree_host_impl_->OnCanDrawStateChangedForTree();
 134 }
 135
 136 LayerImpl* LayerTreeImpl::InnerViewportScrollLayer() const {
 137   return inner_viewport_scroll_layer_;
 138 }
 139
 140 LayerImpl* LayerTreeImpl::OuterViewportScrollLayer() const {
 141   return outer_viewport_scroll_layer_;
 142 }
 143
 144 gfx::Vector2dF LayerTreeImpl::TotalScrollOffset() const {
 145   gfx::Vector2dF offset;
 146
 147   if (inner_viewport_scroll_layer_)
 148     offset += inner_viewport_scroll_layer_->TotalScrollOffset();
 149
 150   if (outer_viewport_scroll_layer_)
 151     offset += outer_viewport_scroll_layer_->TotalScrollOffset();
 152
 153   return offset;
 154 }
 155
 156 gfx::Vector2dF LayerTreeImpl::TotalMaxScrollOffset() const {
 157   gfx::Vector2dF offset;
 158
 159   if (inner_viewport_scroll_layer_)
 160     offset += inner_viewport_scroll_layer_->MaxScrollOffset();
 161
 162   if (outer_viewport_scroll_layer_)
 163     offset += outer_viewport_scroll_layer_->MaxScrollOffset();
 164
 165   return offset;
 166 }
 167 gfx::Vector2dF LayerTreeImpl::TotalScrollDelta() const {
 168   DCHECK(inner_viewport_scroll_layer_);
 169   gfx::Vector2dF delta = inner_viewport_scroll_layer_->ScrollDelta();
 170
 171   if (outer_viewport_scroll_layer_)
 172     delta += outer_viewport_scroll_layer_->ScrollDelta();
 173
 174   return delta;
 175 }
 176
 177 scoped_ptr<LayerImpl> LayerTreeImpl::DetachLayerTree() {
 178   // Clear all data structures that have direct references to the layer tree.
 179   scrolling_layer_id_from_previous_tree_ =
 180     currently_scrolling_layer_ ? currently_scrolling_layer_->id() : 0;
 181   if (inner_viewport_scroll_layer_)
 182     inner_viewport_scroll_layer_->SetScrollOffsetDelegate(NULL);
 183   if (outer_viewport_scroll_layer_)
 184     outer_viewport_scroll_layer_->SetScrollOffsetDelegate(NULL);
 185   inner_viewport_scroll_delegate_proxy_.reset();
 186   outer_viewport_scroll_delegate_proxy_.reset();
 187   inner_viewport_scroll_layer_ = NULL;
 188   outer_viewport_scroll_layer_ = NULL;
 189   page_scale_layer_ = NULL;
 190   currently_scrolling_layer_ = NULL;
 191
 192   render_surface_layer_list_.clear();
 193   set_needs_update_draw_properties();
 194   return root_layer_.Pass();
 195 }
 196
 197 void LayerTreeImpl::PushPropertiesTo(LayerTreeImpl* target_tree) {
 198   // The request queue should have been processed and does not require a push.
 199   DCHECK_EQ(ui_resource_request_queue_.size(), 0u);
 200
 201   if (next_activation_forces_redraw_) {
 202     target_tree->ForceRedrawNextActivation();
 203     next_activation_forces_redraw_ = false;
 204   }
 205
 206   target_tree->PassSwapPromises(&swap_promise_list_);
 207
 208   target_tree->top_controls_layout_height_ = top_controls_layout_height_;
 209   target_tree->top_controls_content_offset_ = top_controls_content_offset_;
 210   target_tree->top_controls_delta_ =
 211       target_tree->top_controls_delta_ -
 212           target_tree->sent_top_controls_delta_;
 213   target_tree->sent_top_controls_delta_ = 0.f;
 214
 215   target_tree->SetPageScaleValues(
 216       page_scale_factor(), min_page_scale_factor(), max_page_scale_factor(),
 217       target_tree->page_scale_delta() / target_tree->sent_page_scale_delta());
 218   target_tree->set_sent_page_scale_delta(1);
 219
 220   target_tree->page_scale_animation_ = page_scale_animation_.Pass();
 221
 222   if (page_scale_layer_ && inner_viewport_scroll_layer_) {
 223     target_tree->SetViewportLayersFromIds(
 224         page_scale_layer_->id(),
 225         inner_viewport_scroll_layer_->id(),
 226         outer_viewport_scroll_layer_ ? outer_viewport_scroll_layer_->id()
 227                                      : Layer::INVALID_ID);
 228   } else {
 229     target_tree->ClearViewportLayers();
 230   }
 231
 232   target_tree->RegisterSelection(selection_start_, selection_end_);
 233
 234   // This should match the property synchronization in
 235   // LayerTreeHost::finishCommitOnImplThread().
 236   target_tree->set_source_frame_number(source_frame_number());
 237   target_tree->set_background_color(background_color());
 238   target_tree->set_has_transparent_background(has_transparent_background());
 239
 240   if (ContentsTexturesPurged())
 241     target_tree->SetContentsTexturesPurged();
 242   else
 243     target_tree->ResetContentsTexturesPurged();
 244
 245   if (ViewportSizeInvalid())
 246     target_tree->SetViewportSizeInvalid();
 247   else
 248     target_tree->ResetViewportSizeInvalid();
 249
 250   if (hud_layer())
 251     target_tree->set_hud_layer(static_cast<HeadsUpDisplayLayerImpl*>(
 252         LayerTreeHostCommon::FindLayerInSubtree(
 253             target_tree->root_layer(), hud_layer()->id())));
 254   else
 255     target_tree->set_hud_layer(NULL);
 256
 257   target_tree->has_ever_been_drawn_ = false;
 258 }
 259
 260 LayerImpl* LayerTreeImpl::InnerViewportContainerLayer() const {
 261   return inner_viewport_scroll_layer_
 262              ? inner_viewport_scroll_layer_->scroll_clip_layer()
 263              : NULL;
 264 }
 265
 266 LayerImpl* LayerTreeImpl::CurrentlyScrollingLayer() const {
 267   DCHECK(IsActiveTree());
 268   return currently_scrolling_layer_;
 269 }
 270
 271 void LayerTreeImpl::SetCurrentlyScrollingLayer(LayerImpl* layer) {
 272   if (currently_scrolling_layer_ == layer)
 273     return;
 274
 275   if (currently_scrolling_layer_ &&
 276       currently_scrolling_layer_->scrollbar_animation_controller())
 277     currently_scrolling_layer_->scrollbar_animation_controller()
 278         ->DidScrollEnd();
 279   currently_scrolling_layer_ = layer;
 280   if (layer && layer->scrollbar_animation_controller())
 281     layer->scrollbar_animation_controller()->DidScrollBegin();
 282 }
 283
 284 void LayerTreeImpl::ClearCurrentlyScrollingLayer() {
 285   SetCurrentlyScrollingLayer(NULL);
 286   scrolling_layer_id_from_previous_tree_ = 0;
 287 }
 288
 289 namespace {
 290
 291 void ForceScrollbarParameterUpdateAfterScaleChange(LayerImpl* current_layer) {
 292   if (!current_layer)
 293     return;
 294
 295   while (current_layer) {
 296     current_layer->ScrollbarParametersDidChange();
 297     current_layer = current_layer->parent();
 298   }
 299 }
 300
 301 }  // namespace
 302
 303 void LayerTreeImpl::SetPageScaleFactorAndLimits(float page_scale_factor,
 304     float min_page_scale_factor, float max_page_scale_factor) {
 305   SetPageScaleValues(page_scale_factor, min_page_scale_factor,
 306       max_page_scale_factor, page_scale_delta_);
 307 }
 308
 309 void LayerTreeImpl::SetPageScaleDelta(float delta) {
 310   SetPageScaleValues(page_scale_factor_, min_page_scale_factor_,
 311       max_page_scale_factor_, delta);
 312 }
 313
 314 void LayerTreeImpl::SetPageScaleValues(float page_scale_factor,
 315       float min_page_scale_factor, float max_page_scale_factor,
 316       float page_scale_delta) {
 317   bool page_scale_changed =
 318       min_page_scale_factor != min_page_scale_factor_ ||
 319       max_page_scale_factor != max_page_scale_factor_ ||
 320       page_scale_factor != page_scale_factor_;
 321
 322   min_page_scale_factor_ = min_page_scale_factor;
 323   max_page_scale_factor_ = max_page_scale_factor;
 324   page_scale_factor_ = page_scale_factor;
 325
 326   float total = page_scale_factor_ * page_scale_delta;
 327   if (min_page_scale_factor_ && total < min_page_scale_factor_)
 328     page_scale_delta = min_page_scale_factor_ / page_scale_factor_;
 329   else if (max_page_scale_factor_ && total > max_page_scale_factor_)
 330     page_scale_delta = max_page_scale_factor_ / page_scale_factor_;
 331
 332   if (page_scale_delta_ == page_scale_delta && !page_scale_changed)
 333     return;
 334
 335   if (page_scale_delta_ != page_scale_delta) {
 336     page_scale_delta_ = page_scale_delta;
 337
 338     if (IsActiveTree()) {
 339       LayerTreeImpl* pending_tree = layer_tree_host_impl_->pending_tree();
 340       if (pending_tree) {
 341         DCHECK_EQ(1, pending_tree->sent_page_scale_delta());
 342         pending_tree->SetPageScaleDelta(
 343             page_scale_delta_ / sent_page_scale_delta_);
 344       }
 345     }
 346
 347     set_needs_update_draw_properties();
 348   }
 349
 350   if (root_layer_scroll_offset_delegate_) {
 351     root_layer_scroll_offset_delegate_->UpdateRootLayerState(
 352         TotalScrollOffset(),
 353         TotalMaxScrollOffset(),
 354         ScrollableSize(),
 355         total_page_scale_factor(),
 356         min_page_scale_factor_,
 357         max_page_scale_factor_);
 358   }
 359
 360   ForceScrollbarParameterUpdateAfterScaleChange(page_scale_layer());
 361 }
 362
 363 gfx::SizeF LayerTreeImpl::ScrollableViewportSize() const {
 364   if (!InnerViewportContainerLayer())
 365     return gfx::SizeF();
 366
 367   return gfx::ScaleSize(InnerViewportContainerLayer()->bounds(),
 368                         1.0f / total_page_scale_factor());
 369 }
 370
 371 gfx::Rect LayerTreeImpl::RootScrollLayerDeviceViewportBounds() const {
 372   LayerImpl* root_scroll_layer = OuterViewportScrollLayer()
 373                                      ? OuterViewportScrollLayer()
 374                                      : InnerViewportScrollLayer();
 375   if (!root_scroll_layer || root_scroll_layer->children().empty())
 376     return gfx::Rect();
 377   LayerImpl* layer = root_scroll_layer->children()[0];
 378   return MathUtil::MapEnclosingClippedRect(layer->screen_space_transform(),
 379                                            gfx::Rect(layer->content_bounds()));
 380 }
 381
 382 static void ApplySentScrollDeltasFromAbortedCommitTo(LayerImpl* layer) {
 383   layer->ApplySentScrollDeltasFromAbortedCommit();
 384 }
 385
 386 void LayerTreeImpl::ApplySentScrollAndScaleDeltasFromAbortedCommit() {
 387   DCHECK(IsActiveTree());
 388
 389   page_scale_factor_ *= sent_page_scale_delta_;
 390   page_scale_delta_ /= sent_page_scale_delta_;
 391   sent_page_scale_delta_ = 1.f;
 392
 393   top_controls_content_offset_ += sent_top_controls_delta_;
 394   top_controls_delta_ -= sent_top_controls_delta_;
 395   sent_top_controls_delta_ = 0.f;
 396
 397   if (!root_layer())
 398     return;
 399
 400   LayerTreeHostCommon::CallFunctionForSubtree(
 401       root_layer(), base::Bind(&ApplySentScrollDeltasFromAbortedCommitTo));
 402 }
 403
 404 static void ApplyScrollDeltasSinceBeginMainFrameTo(LayerImpl* layer) {
 405   layer->ApplyScrollDeltasSinceBeginMainFrame();
 406 }
 407
 408 void LayerTreeImpl::ApplyScrollDeltasSinceBeginMainFrame() {
 409   DCHECK(IsPendingTree());
 410   if (!root_layer())
 411     return;
 412
 413   LayerTreeHostCommon::CallFunctionForSubtree(
 414       root_layer(), base::Bind(&ApplyScrollDeltasSinceBeginMainFrameTo));
 415 }
 416
 417 void LayerTreeImpl::SetViewportLayersFromIds(
 418     int page_scale_layer_id,
 419     int inner_viewport_scroll_layer_id,
 420     int outer_viewport_scroll_layer_id) {
 421   page_scale_layer_ = LayerById(page_scale_layer_id);
 422   DCHECK(page_scale_layer_);
 423
 424   inner_viewport_scroll_layer_ =
 425       LayerById(inner_viewport_scroll_layer_id);
 426   DCHECK(inner_viewport_scroll_layer_);
 427
 428   outer_viewport_scroll_layer_ =
 429       LayerById(outer_viewport_scroll_layer_id);
 430   DCHECK(outer_viewport_scroll_layer_ ||
 431          outer_viewport_scroll_layer_id == Layer::INVALID_ID);
 432
 433   if (!root_layer_scroll_offset_delegate_)
 434     return;
 435
 436   inner_viewport_scroll_delegate_proxy_ = make_scoped_ptr(
 437       new LayerScrollOffsetDelegateProxy(inner_viewport_scroll_layer_,
 438                                          root_layer_scroll_offset_delegate_,
 439                                          this));
 440
 441   if (outer_viewport_scroll_layer_)
 442     outer_viewport_scroll_delegate_proxy_ = make_scoped_ptr(
 443         new LayerScrollOffsetDelegateProxy(outer_viewport_scroll_layer_,
 444                                            root_layer_scroll_offset_delegate_,
 445                                            this));
 446 }
 447
 448 void LayerTreeImpl::ClearViewportLayers() {
 449   page_scale_layer_ = NULL;
 450   inner_viewport_scroll_layer_ = NULL;
 451   outer_viewport_scroll_layer_ = NULL;
 452 }
 453
 454 bool LayerTreeImpl::UpdateDrawProperties() {
 455   if (!needs_update_draw_properties_)
 456     return true;
 457
 458   // For max_texture_size.
 459   if (!layer_tree_host_impl_->renderer())
 460     return false;
 461
 462   if (!root_layer())
 463     return false;
 464
 465   needs_update_draw_properties_ = false;
 466   render_surface_layer_list_.clear();
 467
 468   {
 469     TRACE_EVENT2("cc",
 470                  "LayerTreeImpl::UpdateDrawProperties",
 471                  "IsActive",
 472                  IsActiveTree(),
 473                  "SourceFrameNumber",
 474                  source_frame_number_);
 475     LayerImpl* page_scale_layer =
 476         page_scale_layer_ ? page_scale_layer_ : InnerViewportContainerLayer();
 477     bool can_render_to_separate_surface =
 478         (layer_tree_host_impl_->GetDrawMode() !=
 479          DRAW_MODE_RESOURCELESS_SOFTWARE);
 480
 481     ++render_surface_layer_list_id_;
 482     LayerTreeHostCommon::CalcDrawPropsImplInputs inputs(
 483         root_layer(),
 484         DrawViewportSize(),
 485         layer_tree_host_impl_->DrawTransform(),
 486         device_scale_factor(),
 487         total_page_scale_factor(),
 488         page_scale_layer,
 489         resource_provider()->max_texture_size(),
 490         settings().can_use_lcd_text,
 491         can_render_to_separate_surface,
 492         settings().layer_transforms_should_scale_layer_contents,
 493         &render_surface_layer_list_,
 494         render_surface_layer_list_id_);
 495     LayerTreeHostCommon::CalculateDrawProperties(&inputs);
 496   }
 497
 498   {
 499     TRACE_EVENT2("cc",
 500                  "LayerTreeImpl::UpdateTilePriorities",
 501                  "IsActive",
 502                  IsActiveTree(),
 503                  "SourceFrameNumber",
 504                  source_frame_number_);
 505     scoped_ptr<OcclusionTracker<LayerImpl> > occlusion_tracker;
 506     if (settings().use_occlusion_for_tile_prioritization) {
 507       occlusion_tracker.reset(new OcclusionTracker<LayerImpl>(
 508           root_layer()->render_surface()->content_rect()));
 509       occlusion_tracker->set_minimum_tracking_size(
 510           settings().minimum_occlusion_tracking_size);
 511     }
 512
 513     bool resourceless_software_draw = (layer_tree_host_impl_->GetDrawMode() ==
 514                                        DRAW_MODE_RESOURCELESS_SOFTWARE);
 515
 516     // LayerIterator is used here instead of CallFunctionForSubtree to only
 517     // UpdateTilePriorities on layers that will be visible (and thus have valid
 518     // draw properties) and not because any ordering is required.
 519     typedef LayerIterator<LayerImpl> LayerIteratorType;
 520     LayerIteratorType end = LayerIteratorType::End(&render_surface_layer_list_);
 521     for (LayerIteratorType it =
 522              LayerIteratorType::Begin(&render_surface_layer_list_);
 523          it != end;
 524          ++it) {
 525       if (occlusion_tracker)
 526         occlusion_tracker->EnterLayer(it);
 527
 528       LayerImpl* layer = *it;
 529       const Occlusion& occlusion_in_content_space =
 530           occlusion_tracker ? occlusion_tracker->GetCurrentOcclusionForLayer(
 531                                   layer->draw_transform())
 532                             : Occlusion();
 533
 534       if (it.represents_itself()) {
 535         layer->UpdateTiles(occlusion_in_content_space,
 536                            resourceless_software_draw);
 537       }
 538
 539       if (!it.represents_contributing_render_surface()) {
 540         if (occlusion_tracker)
 541           occlusion_tracker->LeaveLayer(it);
 542         continue;
 543       }
 544
 545       if (layer->mask_layer()) {
 546         layer->mask_layer()->UpdateTiles(occlusion_in_content_space,
 547                                          resourceless_software_draw);
 548       }
 549       if (layer->replica_layer() && layer->replica_layer()->mask_layer()) {
 550         layer->replica_layer()->mask_layer()->UpdateTiles(
 551             occlusion_in_content_space, resourceless_software_draw);
 552       }
 553
 554       if (occlusion_tracker)
 555         occlusion_tracker->LeaveLayer(it);
 556     }
 557   }
 558
 559   DCHECK(!needs_update_draw_properties_) <<
 560       "CalcDrawProperties should not set_needs_update_draw_properties()";
 561   return true;
 562 }
 563
 564 const LayerImplList& LayerTreeImpl::RenderSurfaceLayerList() const {
 565   // If this assert triggers, then the list is dirty.
 566   DCHECK(!needs_update_draw_properties_);
 567   return render_surface_layer_list_;
 568 }
 569
 570 gfx::Size LayerTreeImpl::ScrollableSize() const {
 571   LayerImpl* root_scroll_layer = OuterViewportScrollLayer()
 572                                      ? OuterViewportScrollLayer()
 573                                      : InnerViewportScrollLayer();
 574   if (!root_scroll_layer || root_scroll_layer->children().empty())
 575     return gfx::Size();
 576   return root_scroll_layer->children()[0]->bounds();
 577 }
 578
 579 LayerImpl* LayerTreeImpl::LayerById(int id) {
 580   LayerIdMap::iterator iter = layer_id_map_.find(id);
 581   return iter != layer_id_map_.end() ? iter->second : NULL;
 582 }
 583
 584 void LayerTreeImpl::RegisterLayer(LayerImpl* layer) {
 585   DCHECK(!LayerById(layer->id()));
 586   layer_id_map_[layer->id()] = layer;
 587 }
 588
 589 void LayerTreeImpl::UnregisterLayer(LayerImpl* layer) {
 590   DCHECK(LayerById(layer->id()));
 591   layer_id_map_.erase(layer->id());
 592 }
 593
 594 size_t LayerTreeImpl::NumLayers() {
 595   return layer_id_map_.size();
 596 }
 597
 598 void LayerTreeImpl::PushPersistedState(LayerTreeImpl* pending_tree) {
 599   pending_tree->SetCurrentlyScrollingLayer(
 600       LayerTreeHostCommon::FindLayerInSubtree(pending_tree->root_layer(),
 601           currently_scrolling_layer_ ? currently_scrolling_layer_->id() : 0));
 602 }
 603
 604 static void DidBecomeActiveRecursive(LayerImpl* layer) {
 605   layer->DidBecomeActive();
 606   if (layer->mask_layer())
 607     layer->mask_layer()->DidBecomeActive();
 608   if (layer->replica_layer() && layer->replica_layer()->mask_layer())
 609     layer->replica_layer()->mask_layer()->DidBecomeActive();
 610
 611   for (size_t i = 0; i < layer->children().size(); ++i)
 612     DidBecomeActiveRecursive(layer->children()[i]);
 613 }
 614
 615 void LayerTreeImpl::DidBecomeActive() {
 616   if (next_activation_forces_redraw_) {
 617     layer_tree_host_impl_->SetFullRootLayerDamage();
 618     next_activation_forces_redraw_ = false;
 619   }
 620
 621   if (scrolling_layer_id_from_previous_tree_) {
 622     currently_scrolling_layer_ = LayerTreeHostCommon::FindLayerInSubtree(
 623         root_layer(), scrolling_layer_id_from_previous_tree_);
 624   }
 625
 626   // Always reset this flag on activation, as we would only have activated
 627   // if we were in a good state.
 628   ResetRequiresHighResToDraw();
 629
 630   if (root_layer())
 631     DidBecomeActiveRecursive(root_layer());
 632
 633   devtools_instrumentation::DidActivateLayerTree(layer_tree_host_impl_->id(),
 634                                                  source_frame_number_);
 635 }
 636
 637 bool LayerTreeImpl::ContentsTexturesPurged() const {
 638   return contents_textures_purged_;
 639 }
 640
 641 void LayerTreeImpl::SetContentsTexturesPurged() {
 642   if (contents_textures_purged_)
 643     return;
 644   contents_textures_purged_ = true;
 645   layer_tree_host_impl_->OnCanDrawStateChangedForTree();
 646 }
 647
 648 void LayerTreeImpl::ResetContentsTexturesPurged() {
 649   if (!contents_textures_purged_)
 650     return;
 651   contents_textures_purged_ = false;
 652   layer_tree_host_impl_->OnCanDrawStateChangedForTree();
 653 }
 654
 655 void LayerTreeImpl::SetRequiresHighResToDraw() {
 656   requires_high_res_to_draw_ = true;
 657 }
 658
 659 void LayerTreeImpl::ResetRequiresHighResToDraw() {
 660   requires_high_res_to_draw_ = false;
 661 }
 662
 663 bool LayerTreeImpl::RequiresHighResToDraw() const {
 664   return requires_high_res_to_draw_;
 665 }
 666
 667 bool LayerTreeImpl::ViewportSizeInvalid() const {
 668   return viewport_size_invalid_;
 669 }
 670
 671 void LayerTreeImpl::SetViewportSizeInvalid() {
 672   viewport_size_invalid_ = true;
 673   layer_tree_host_impl_->OnCanDrawStateChangedForTree();
 674 }
 675
 676 void LayerTreeImpl::ResetViewportSizeInvalid() {
 677   viewport_size_invalid_ = false;
 678   layer_tree_host_impl_->OnCanDrawStateChangedForTree();
 679 }
 680
 681 Proxy* LayerTreeImpl::proxy() const {
 682   return layer_tree_host_impl_->proxy();
 683 }
 684
 685 const LayerTreeSettings& LayerTreeImpl::settings() const {
 686   return layer_tree_host_impl_->settings();
 687 }
 688
 689 const RendererCapabilitiesImpl& LayerTreeImpl::GetRendererCapabilities() const {
 690   return layer_tree_host_impl_->GetRendererCapabilities();
 691 }
 692
 693 ContextProvider* LayerTreeImpl::context_provider() const {
 694   return output_surface()->context_provider();
 695 }
 696
 697 OutputSurface* LayerTreeImpl::output_surface() const {
 698   return layer_tree_host_impl_->output_surface();
 699 }
 700
 701 ResourceProvider* LayerTreeImpl::resource_provider() const {
 702   return layer_tree_host_impl_->resource_provider();
 703 }
 704
 705 TileManager* LayerTreeImpl::tile_manager() const {
 706   return layer_tree_host_impl_->tile_manager();
 707 }
 708
 709 FrameRateCounter* LayerTreeImpl::frame_rate_counter() const {
 710   return layer_tree_host_impl_->fps_counter();
 711 }
 712
 713 PaintTimeCounter* LayerTreeImpl::paint_time_counter() const {
 714   return layer_tree_host_impl_->paint_time_counter();
 715 }
 716
 717 MemoryHistory* LayerTreeImpl::memory_history() const {
 718   return layer_tree_host_impl_->memory_history();
 719 }
 720
 721 gfx::Size LayerTreeImpl::device_viewport_size() const {
 722   return layer_tree_host_impl_->device_viewport_size();
 723 }
 724
 725 bool LayerTreeImpl::IsActiveTree() const {
 726   return layer_tree_host_impl_->active_tree() == this;
 727 }
 728
 729 bool LayerTreeImpl::IsPendingTree() const {
 730   return layer_tree_host_impl_->pending_tree() == this;
 731 }
 732
 733 bool LayerTreeImpl::IsRecycleTree() const {
 734   return layer_tree_host_impl_->recycle_tree() == this;
 735 }
 736
 737 LayerImpl* LayerTreeImpl::FindActiveTreeLayerById(int id) {
 738   LayerTreeImpl* tree = layer_tree_host_impl_->active_tree();
 739   if (!tree)
 740     return NULL;
 741   return tree->LayerById(id);
 742 }
 743
 744 LayerImpl* LayerTreeImpl::FindPendingTreeLayerById(int id) {
 745   LayerTreeImpl* tree = layer_tree_host_impl_->pending_tree();
 746   if (!tree)
 747     return NULL;
 748   return tree->LayerById(id);
 749 }
 750
 751 LayerImpl* LayerTreeImpl::FindRecycleTreeLayerById(int id) {
 752   LayerTreeImpl* tree = layer_tree_host_impl_->recycle_tree();
 753   if (!tree)
 754     return NULL;
 755   return tree->LayerById(id);
 756 }
 757
 758 bool LayerTreeImpl::PinchGestureActive() const {
 759   return layer_tree_host_impl_->pinch_gesture_active();
 760 }
 761
 762 BeginFrameArgs LayerTreeImpl::CurrentBeginFrameArgs() const {
 763   return layer_tree_host_impl_->CurrentBeginFrameArgs();
 764 }
 765
 766 base::TimeDelta LayerTreeImpl::begin_impl_frame_interval() const {
 767   return layer_tree_host_impl_->begin_impl_frame_interval();
 768 }
 769
 770 void LayerTreeImpl::SetNeedsCommit() {
 771   layer_tree_host_impl_->SetNeedsCommit();
 772 }
 773
 774 gfx::Rect LayerTreeImpl::DeviceViewport() const {
 775   return layer_tree_host_impl_->DeviceViewport();
 776 }
 777
 778 gfx::Size LayerTreeImpl::DrawViewportSize() const {
 779   return layer_tree_host_impl_->DrawViewportSize();
 780 }
 781
 782 const gfx::Rect LayerTreeImpl::ViewportRectForTilePriority() const {
 783   return layer_tree_host_impl_->ViewportRectForTilePriority();
 784 }
 785
 786 scoped_ptr<ScrollbarAnimationController>
 787 LayerTreeImpl::CreateScrollbarAnimationController(LayerImpl* scrolling_layer) {
 788   DCHECK(settings().scrollbar_fade_delay_ms);
 789   DCHECK(settings().scrollbar_fade_duration_ms);
 790   base::TimeDelta delay =
 791       base::TimeDelta::FromMilliseconds(settings().scrollbar_fade_delay_ms);
 792   base::TimeDelta duration =
 793       base::TimeDelta::FromMilliseconds(settings().scrollbar_fade_duration_ms);
 794   switch (settings().scrollbar_animator) {
 795     case LayerTreeSettings::LinearFade: {
 796       return ScrollbarAnimationControllerLinearFade::Create(
 797                  scrolling_layer, layer_tree_host_impl_, delay, duration)
 798           .PassAs<ScrollbarAnimationController>();
 799     }
 800     case LayerTreeSettings::Thinning: {
 801       return ScrollbarAnimationControllerThinning::Create(
 802                  scrolling_layer, layer_tree_host_impl_, delay, duration)
 803           .PassAs<ScrollbarAnimationController>();
 804     }
 805     case LayerTreeSettings::NoAnimator:
 806       NOTREACHED();
 807       break;
 808   }
 809   return scoped_ptr<ScrollbarAnimationController>();
 810 }
 811
 812 void LayerTreeImpl::DidAnimateScrollOffset() {
 813   layer_tree_host_impl_->DidAnimateScrollOffset();
 814 }
 815
 816 bool LayerTreeImpl::use_gpu_rasterization() const {
 817   return layer_tree_host_impl_->use_gpu_rasterization();
 818 }
 819
 820 bool LayerTreeImpl::create_low_res_tiling() const {
 821   return layer_tree_host_impl_->create_low_res_tiling();
 822 }
 823
 824 void LayerTreeImpl::SetNeedsRedraw() {
 825   layer_tree_host_impl_->SetNeedsRedraw();
 826 }
 827
 828 const LayerTreeDebugState& LayerTreeImpl::debug_state() const {
 829   return layer_tree_host_impl_->debug_state();
 830 }
 831
 832 float LayerTreeImpl::device_scale_factor() const {
 833   return layer_tree_host_impl_->device_scale_factor();
 834 }
 835
 836 DebugRectHistory* LayerTreeImpl::debug_rect_history() const {
 837   return layer_tree_host_impl_->debug_rect_history();
 838 }
 839
 840 AnimationRegistrar* LayerTreeImpl::animationRegistrar() const {
 841   return layer_tree_host_impl_->animation_registrar();
 842 }
 843
 844 void LayerTreeImpl::GetAllTilesForTracing(std::set<const Tile*>* tiles) const {
 845   typedef LayerIterator<LayerImpl> LayerIteratorType;
 846   LayerIteratorType end = LayerIteratorType::End(&render_surface_layer_list_);
 847   for (LayerIteratorType it =
 848            LayerIteratorType::Begin(&render_surface_layer_list_);
 849        it != end;
 850        ++it) {
 851     if (!it.represents_itself())
 852       continue;
 853     LayerImpl* layer_impl = *it;
 854     layer_impl->GetAllTilesForTracing(tiles);
 855   }
 856 }
 857
 858 void LayerTreeImpl::AsValueInto(base::debug::TracedValue* state) const {
 859   TracedValue::MakeDictIntoImplicitSnapshot(state, "cc::LayerTreeImpl", this);
 860   state->SetInteger("source_frame_number", source_frame_number_);
 861
 862   state->BeginDictionary("root_layer");
 863   root_layer_->AsValueInto(state);
 864   state->EndDictionary();
 865
 866   state->BeginArray("render_surface_layer_list");
 867   typedef LayerIterator<LayerImpl> LayerIteratorType;
 868   LayerIteratorType end = LayerIteratorType::End(&render_surface_layer_list_);
 869   for (LayerIteratorType it = LayerIteratorType::Begin(
 870            &render_surface_layer_list_); it != end; ++it) {
 871     if (!it.represents_itself())
 872       continue;
 873     TracedValue::AppendIDRef(*it, state);
 874   }
 875   state->EndArray();
 876
 877   state->BeginArray("swap_promise_trace_ids");
 878   for (size_t i = 0; i < swap_promise_list_.size(); i++)
 879     state->AppendDouble(swap_promise_list_[i]->TraceId());
 880   state->EndArray();
 881 }
 882
 883 void LayerTreeImpl::SetRootLayerScrollOffsetDelegate(
 884     LayerScrollOffsetDelegate* root_layer_scroll_offset_delegate) {
 885   if (root_layer_scroll_offset_delegate_ == root_layer_scroll_offset_delegate)
 886     return;
 887
 888   if (!root_layer_scroll_offset_delegate) {
 889     // Make sure we remove the proxies from their layers before
 890     // releasing them.
 891     if (InnerViewportScrollLayer())
 892       InnerViewportScrollLayer()->SetScrollOffsetDelegate(NULL);
 893     if (OuterViewportScrollLayer())
 894       OuterViewportScrollLayer()->SetScrollOffsetDelegate(NULL);
 895     inner_viewport_scroll_delegate_proxy_.reset();
 896     outer_viewport_scroll_delegate_proxy_.reset();
 897   }
 898
 899   root_layer_scroll_offset_delegate_ = root_layer_scroll_offset_delegate;
 900
 901   if (root_layer_scroll_offset_delegate_) {
 902     root_layer_scroll_offset_delegate_->UpdateRootLayerState(
 903         TotalScrollOffset(),
 904         TotalMaxScrollOffset(),
 905         ScrollableSize(),
 906         total_page_scale_factor(),
 907         min_page_scale_factor(),
 908         max_page_scale_factor());
 909
 910     if (inner_viewport_scroll_layer_) {
 911       inner_viewport_scroll_delegate_proxy_ = make_scoped_ptr(
 912           new LayerScrollOffsetDelegateProxy(InnerViewportScrollLayer(),
 913                                              root_layer_scroll_offset_delegate_,
 914                                              this));
 915       inner_viewport_scroll_layer_->SetScrollOffsetDelegate(
 916           inner_viewport_scroll_delegate_proxy_.get());
 917     }
 918
 919     if (outer_viewport_scroll_layer_) {
 920       outer_viewport_scroll_delegate_proxy_ = make_scoped_ptr(
 921           new LayerScrollOffsetDelegateProxy(OuterViewportScrollLayer(),
 922                                              root_layer_scroll_offset_delegate_,
 923                                              this));
 924       outer_viewport_scroll_layer_->SetScrollOffsetDelegate(
 925           outer_viewport_scroll_delegate_proxy_.get());
 926     }
 927   }
 928 }
 929
 930 void LayerTreeImpl::UpdateScrollOffsetDelegate() {
 931   DCHECK(InnerViewportScrollLayer());
 932   DCHECK(root_layer_scroll_offset_delegate_);
 933
 934   gfx::Vector2dF offset =
 935       inner_viewport_scroll_delegate_proxy_->last_set_scroll_offset();
 936
 937   if (OuterViewportScrollLayer())
 938     offset += outer_viewport_scroll_delegate_proxy_->last_set_scroll_offset();
 939
 940   root_layer_scroll_offset_delegate_->UpdateRootLayerState(
 941       offset,
 942       TotalMaxScrollOffset(),
 943       ScrollableSize(),
 944       total_page_scale_factor(),
 945       min_page_scale_factor(),
 946       max_page_scale_factor());
 947 }
 948
 949 gfx::Vector2dF LayerTreeImpl::GetDelegatedScrollOffset(LayerImpl* layer) {
 950   DCHECK(root_layer_scroll_offset_delegate_);
 951   DCHECK(InnerViewportScrollLayer());
 952   if (layer == InnerViewportScrollLayer() && !OuterViewportScrollLayer())
 953     return root_layer_scroll_offset_delegate_->GetTotalScrollOffset();
 954
 955   // If we get here, we have both inner/outer viewports, and need to distribute
 956   // the scroll offset between them.
 957   DCHECK(inner_viewport_scroll_delegate_proxy_);
 958   DCHECK(outer_viewport_scroll_delegate_proxy_);
 959   gfx::Vector2dF inner_viewport_offset =
 960       inner_viewport_scroll_delegate_proxy_->last_set_scroll_offset();
 961   gfx::Vector2dF outer_viewport_offset =
 962       outer_viewport_scroll_delegate_proxy_->last_set_scroll_offset();
 963
 964   // It may be nothing has changed.
 965   gfx::Vector2dF delegate_offset =
 966       root_layer_scroll_offset_delegate_->GetTotalScrollOffset();
 967   if (inner_viewport_offset + outer_viewport_offset == delegate_offset) {
 968     if (layer == InnerViewportScrollLayer())
 969       return inner_viewport_offset;
 970     else
 971       return outer_viewport_offset;
 972   }
 973
 974   gfx::Vector2d max_outer_viewport_scroll_offset =
 975       OuterViewportScrollLayer()->MaxScrollOffset();
 976
 977   outer_viewport_offset = delegate_offset - inner_viewport_offset;
 978   outer_viewport_offset.SetToMin(max_outer_viewport_scroll_offset);
 979   outer_viewport_offset.SetToMax(gfx::Vector2d());
 980
 981   if (layer == OuterViewportScrollLayer())
 982     return outer_viewport_offset;
 983
 984   inner_viewport_offset = delegate_offset - outer_viewport_offset;
 985
 986   return inner_viewport_offset;
 987 }
 988
 989 void LayerTreeImpl::QueueSwapPromise(scoped_ptr<SwapPromise> swap_promise) {
 990   DCHECK(swap_promise);
 991   swap_promise_list_.push_back(swap_promise.Pass());
 992 }
 993
 994 void LayerTreeImpl::PassSwapPromises(
 995     ScopedPtrVector<SwapPromise>* new_swap_promise) {
 996   swap_promise_list_.insert_and_take(swap_promise_list_.end(),
 997                                      new_swap_promise);
 998   new_swap_promise->clear();
 999 }
1000
1001 void LayerTreeImpl::FinishSwapPromises(CompositorFrameMetadata* metadata) {
1002   for (size_t i = 0; i < swap_promise_list_.size(); i++)
1003     swap_promise_list_[i]->DidSwap(metadata);
1004   swap_promise_list_.clear();
1005 }
1006
1007 void LayerTreeImpl::BreakSwapPromises(SwapPromise::DidNotSwapReason reason) {
1008   for (size_t i = 0; i < swap_promise_list_.size(); i++)
1009     swap_promise_list_[i]->DidNotSwap(reason);
1010   swap_promise_list_.clear();
1011 }
1012
1013 void LayerTreeImpl::DidModifyTilePriorities() {
1014   layer_tree_host_impl_->DidModifyTilePriorities();
1015 }
1016
1017 void LayerTreeImpl::set_ui_resource_request_queue(
1018     const UIResourceRequestQueue& queue) {
1019   ui_resource_request_queue_ = queue;
1020 }
1021
1022 ResourceProvider::ResourceId LayerTreeImpl::ResourceIdForUIResource(
1023     UIResourceId uid) const {
1024   return layer_tree_host_impl_->ResourceIdForUIResource(uid);
1025 }
1026
1027 bool LayerTreeImpl::IsUIResourceOpaque(UIResourceId uid) const {
1028   return layer_tree_host_impl_->IsUIResourceOpaque(uid);
1029 }
1030
1031 void LayerTreeImpl::ProcessUIResourceRequestQueue() {
1032   while (ui_resource_request_queue_.size() > 0) {
1033     UIResourceRequest req = ui_resource_request_queue_.front();
1034     ui_resource_request_queue_.pop_front();
1035
1036     switch (req.GetType()) {
1037       case UIResourceRequest::UIResourceCreate:
1038         layer_tree_host_impl_->CreateUIResource(req.GetId(), req.GetBitmap());
1039         break;
1040       case UIResourceRequest::UIResourceDelete:
1041         layer_tree_host_impl_->DeleteUIResource(req.GetId());
1042         break;
1043       case UIResourceRequest::UIResourceInvalidRequest:
1044         NOTREACHED();
1045         break;
1046     }
1047   }
1048
1049   // If all UI resource evictions were not recreated by processing this queue,
1050   // then another commit is required.
1051   if (layer_tree_host_impl_->EvictedUIResourcesExist())
1052     layer_tree_host_impl_->SetNeedsCommit();
1053 }
1054
1055 void LayerTreeImpl::AddLayerWithCopyOutputRequest(LayerImpl* layer) {
1056   // Only the active tree needs to know about layers with copy requests, as
1057   // they are aborted if not serviced during draw.
1058   DCHECK(IsActiveTree());
1059
1060   // DCHECK(std::find(layers_with_copy_output_request_.begin(),
1061   //                 layers_with_copy_output_request_.end(),
1062   //                 layer) == layers_with_copy_output_request_.end());
1063   // TODO(danakj): Remove this once crash is found crbug.com/309777
1064   for (size_t i = 0; i < layers_with_copy_output_request_.size(); ++i) {
1065     CHECK(layers_with_copy_output_request_[i] != layer)
1066         << i << " of " << layers_with_copy_output_request_.size();
1067   }
1068   layers_with_copy_output_request_.push_back(layer);
1069 }
1070
1071 void LayerTreeImpl::RemoveLayerWithCopyOutputRequest(LayerImpl* layer) {
1072   // Only the active tree needs to know about layers with copy requests, as
1073   // they are aborted if not serviced during draw.
1074   DCHECK(IsActiveTree());
1075
1076   std::vector<LayerImpl*>::iterator it = std::find(
1077       layers_with_copy_output_request_.begin(),
1078       layers_with_copy_output_request_.end(),
1079       layer);
1080   DCHECK(it != layers_with_copy_output_request_.end());
1081   layers_with_copy_output_request_.erase(it);
1082
1083   // TODO(danakj): Remove this once crash is found crbug.com/309777
1084   for (size_t i = 0; i < layers_with_copy_output_request_.size(); ++i) {
1085     CHECK(layers_with_copy_output_request_[i] != layer)
1086         << i << " of " << layers_with_copy_output_request_.size();
1087   }
1088 }
1089
1090 const std::vector<LayerImpl*>& LayerTreeImpl::LayersWithCopyOutputRequest()
1091     const {
1092   // Only the active tree needs to know about layers with copy requests, as
1093   // they are aborted if not serviced during draw.
1094   DCHECK(IsActiveTree());
1095
1096   return layers_with_copy_output_request_;
1097 }
1098
1099 void LayerTreeImpl::ReleaseResourcesRecursive(LayerImpl* current) {
1100   DCHECK(current);
1101   current->ReleaseResources();
1102   if (current->mask_layer())
1103     ReleaseResourcesRecursive(current->mask_layer());
1104   if (current->replica_layer())
1105     ReleaseResourcesRecursive(current->replica_layer());
1106   for (size_t i = 0; i < current->children().size(); ++i)
1107     ReleaseResourcesRecursive(current->children()[i]);
1108 }
1109
1110 template <typename LayerType>
1111 static inline bool LayerClipsSubtree(LayerType* layer) {
1112   return layer->masks_to_bounds() || layer->mask_layer();
1113 }
1114
1115 static bool PointHitsRect(
1116     const gfx::PointF& screen_space_point,
1117     const gfx::Transform& local_space_to_screen_space_transform,
1118     const gfx::RectF& local_space_rect,
1119     float* distance_to_camera) {
1120   // If the transform is not invertible, then assume that this point doesn't hit
1121   // this rect.
1122   gfx::Transform inverse_local_space_to_screen_space(
1123       gfx::Transform::kSkipInitialization);
1124   if (!local_space_to_screen_space_transform.GetInverse(
1125           &inverse_local_space_to_screen_space))
1126     return false;
1127
1128   // Transform the hit test point from screen space to the local space of the
1129   // given rect.
1130   bool clipped = false;
1131   gfx::Point3F planar_point = MathUtil::ProjectPoint3D(
1132       inverse_local_space_to_screen_space, screen_space_point, &clipped);
1133   gfx::PointF hit_test_point_in_local_space =
1134       gfx::PointF(planar_point.x(), planar_point.y());
1135
1136   // If ProjectPoint could not project to a valid value, then we assume that
1137   // this point doesn't hit this rect.
1138   if (clipped)
1139     return false;
1140
1141   if (!local_space_rect.Contains(hit_test_point_in_local_space))
1142     return false;
1143
1144   if (distance_to_camera) {
1145     // To compute the distance to the camera, we have to take the planar point
1146     // and pull it back to world space and compute the displacement along the
1147     // z-axis.
1148     gfx::Point3F planar_point_in_screen_space(planar_point);
1149     local_space_to_screen_space_transform.TransformPoint(
1150         &planar_point_in_screen_space);
1151     *distance_to_camera = planar_point_in_screen_space.z();
1152   }
1153
1154   return true;
1155 }
1156
1157 static bool PointHitsRegion(const gfx::PointF& screen_space_point,
1158                             const gfx::Transform& screen_space_transform,
1159                             const Region& layer_space_region,
1160                             float layer_content_scale_x,
1161                             float layer_content_scale_y) {
1162   // If the transform is not invertible, then assume that this point doesn't hit
1163   // this region.
1164   gfx::Transform inverse_screen_space_transform(
1165       gfx::Transform::kSkipInitialization);
1166   if (!screen_space_transform.GetInverse(&inverse_screen_space_transform))
1167     return false;
1168
1169   // Transform the hit test point from screen space to the local space of the
1170   // given region.
1171   bool clipped = false;
1172   gfx::PointF hit_test_point_in_content_space = MathUtil::ProjectPoint(
1173       inverse_screen_space_transform, screen_space_point, &clipped);
1174   gfx::PointF hit_test_point_in_layer_space =
1175       gfx::ScalePoint(hit_test_point_in_content_space,
1176                       1.f / layer_content_scale_x,
1177                       1.f / layer_content_scale_y);
1178
1179   // If ProjectPoint could not project to a valid value, then we assume that
1180   // this point doesn't hit this region.
1181   if (clipped)
1182     return false;
1183
1184   return layer_space_region.Contains(
1185       gfx::ToRoundedPoint(hit_test_point_in_layer_space));
1186 }
1187
1188 static const LayerImpl* GetNextClippingLayer(const LayerImpl* layer) {
1189   if (layer->scroll_parent())
1190     return layer->scroll_parent();
1191   if (layer->clip_parent())
1192     return layer->clip_parent();
1193   return layer->parent();
1194 }
1195
1196 static bool PointIsClippedBySurfaceOrClipRect(
1197     const gfx::PointF& screen_space_point,
1198     const LayerImpl* layer) {
1199   // Walk up the layer tree and hit-test any render_surfaces and any layer
1200   // clip rects that are active.
1201   for (; layer; layer = GetNextClippingLayer(layer)) {
1202     if (layer->render_surface() &&
1203         !PointHitsRect(screen_space_point,
1204                        layer->render_surface()->screen_space_transform(),
1205                        layer->render_surface()->content_rect(),
1206                        NULL))
1207       return true;
1208
1209     if (LayerClipsSubtree(layer) &&
1210         !PointHitsRect(screen_space_point,
1211                        layer->screen_space_transform(),
1212                        gfx::Rect(layer->content_bounds()),
1213                        NULL))
1214       return true;
1215   }
1216
1217   // If we have finished walking all ancestors without having already exited,
1218   // then the point is not clipped by any ancestors.
1219   return false;
1220 }
1221
1222 static bool PointHitsLayer(const LayerImpl* layer,
1223                            const gfx::PointF& screen_space_point,
1224                            float* distance_to_intersection) {
1225   gfx::RectF content_rect(layer->content_bounds());
1226   if (!PointHitsRect(screen_space_point,
1227                      layer->screen_space_transform(),
1228                      content_rect,
1229                      distance_to_intersection))
1230     return false;
1231
1232   // At this point, we think the point does hit the layer, but we need to walk
1233   // up the parents to ensure that the layer was not clipped in such a way
1234   // that the hit point actually should not hit the layer.
1235   if (PointIsClippedBySurfaceOrClipRect(screen_space_point, layer))
1236     return false;
1237
1238   // Skip the HUD layer.
1239   if (layer == layer->layer_tree_impl()->hud_layer())
1240     return false;
1241
1242   return true;
1243 }
1244
1245 struct FindClosestMatchingLayerDataForRecursion {
1246   FindClosestMatchingLayerDataForRecursion()
1247       : closest_match(NULL),
1248         closest_distance(-std::numeric_limits<float>::infinity()) {}
1249   LayerImpl* closest_match;
1250   // Note that the positive z-axis points towards the camera, so bigger means
1251   // closer in this case, counterintuitively.
1252   float closest_distance;
1253 };
1254
1255 template <typename Functor>
1256 static void FindClosestMatchingLayer(
1257     const gfx::PointF& screen_space_point,
1258     LayerImpl* layer,
1259     const Functor& func,
1260     FindClosestMatchingLayerDataForRecursion* data_for_recursion) {
1261   for (int i = layer->children().size() - 1; i >= 0; --i) {
1262     FindClosestMatchingLayer(
1263         screen_space_point, layer->children()[i], func, data_for_recursion);
1264   }
1265
1266   float distance_to_intersection = 0.f;
1267   if (func(layer) &&
1268       PointHitsLayer(layer, screen_space_point, &distance_to_intersection) &&
1269       ((!data_for_recursion->closest_match ||
1270         distance_to_intersection > data_for_recursion->closest_distance))) {
1271     data_for_recursion->closest_distance = distance_to_intersection;
1272     data_for_recursion->closest_match = layer;
1273   }
1274 }
1275
1276 static bool ScrollsAnyDrawnRenderSurfaceLayerListMember(LayerImpl* layer) {
1277   if (!layer->scrollable())
1278     return false;
1279   if (layer->IsDrawnRenderSurfaceLayerListMember())
1280     return true;
1281   if (!layer->scroll_children())
1282     return false;
1283   for (std::set<LayerImpl*>::const_iterator it =
1284            layer->scroll_children()->begin();
1285        it != layer->scroll_children()->end();
1286        ++it) {
1287     if ((*it)->IsDrawnRenderSurfaceLayerListMember())
1288       return true;
1289   }
1290   return false;
1291 }
1292
1293 struct FindScrollingLayerFunctor {
1294   bool operator()(LayerImpl* layer) const {
1295     return ScrollsAnyDrawnRenderSurfaceLayerListMember(layer);
1296   }
1297 };
1298
1299 LayerImpl* LayerTreeImpl::FindFirstScrollingLayerThatIsHitByPoint(
1300     const gfx::PointF& screen_space_point) {
1301   FindClosestMatchingLayerDataForRecursion data_for_recursion;
1302   FindClosestMatchingLayer(screen_space_point,
1303                            root_layer(),
1304                            FindScrollingLayerFunctor(),
1305                            &data_for_recursion);
1306   return data_for_recursion.closest_match;
1307 }
1308
1309 struct HitTestVisibleScrollableOrTouchableFunctor {
1310   bool operator()(LayerImpl* layer) const {
1311     return layer->IsDrawnRenderSurfaceLayerListMember() ||
1312            ScrollsAnyDrawnRenderSurfaceLayerListMember(layer) ||
1313            !layer->touch_event_handler_region().IsEmpty() ||
1314            layer->have_wheel_event_handlers();
1315   }
1316 };
1317
1318 LayerImpl* LayerTreeImpl::FindLayerThatIsHitByPoint(
1319     const gfx::PointF& screen_space_point) {
1320   if (!root_layer())
1321     return NULL;
1322   if (!UpdateDrawProperties())
1323     return NULL;
1324   FindClosestMatchingLayerDataForRecursion data_for_recursion;
1325   FindClosestMatchingLayer(screen_space_point,
1326                            root_layer(),
1327                            HitTestVisibleScrollableOrTouchableFunctor(),
1328                            &data_for_recursion);
1329   return data_for_recursion.closest_match;
1330 }
1331
1332 static bool LayerHasTouchEventHandlersAt(const gfx::PointF& screen_space_point,
1333                                          LayerImpl* layer_impl) {
1334   if (layer_impl->touch_event_handler_region().IsEmpty())
1335     return false;
1336
1337   if (!PointHitsRegion(screen_space_point,
1338                        layer_impl->screen_space_transform(),
1339                        layer_impl->touch_event_handler_region(),
1340                        layer_impl->contents_scale_x(),
1341                        layer_impl->contents_scale_y()))
1342     return false;
1343
1344   // At this point, we think the point does hit the touch event handler region
1345   // on the layer, but we need to walk up the parents to ensure that the layer
1346   // was not clipped in such a way that the hit point actually should not hit
1347   // the layer.
1348   if (PointIsClippedBySurfaceOrClipRect(screen_space_point, layer_impl))
1349     return false;
1350
1351   return true;
1352 }
1353
1354 struct FindTouchEventLayerFunctor {
1355   bool operator()(LayerImpl* layer) const {
1356     return LayerHasTouchEventHandlersAt(screen_space_point, layer);
1357   }
1358   const gfx::PointF screen_space_point;
1359 };
1360
1361 LayerImpl* LayerTreeImpl::FindLayerThatIsHitByPointInTouchHandlerRegion(
1362     const gfx::PointF& screen_space_point) {
1363   if (!root_layer())
1364     return NULL;
1365   if (!UpdateDrawProperties())
1366     return NULL;
1367   FindTouchEventLayerFunctor func = {screen_space_point};
1368   FindClosestMatchingLayerDataForRecursion data_for_recursion;
1369   FindClosestMatchingLayer(
1370       screen_space_point, root_layer(), func, &data_for_recursion);
1371   return data_for_recursion.closest_match;
1372 }
1373
1374 void LayerTreeImpl::RegisterSelection(const LayerSelectionBound& start,
1375                                       const LayerSelectionBound& end) {
1376   selection_start_ = start;
1377   selection_end_ = end;
1378 }
1379
1380 static ViewportSelectionBound ComputeViewportSelection(
1381     const LayerSelectionBound& layer_bound,
1382     LayerImpl* layer,
1383     float device_scale_factor) {
1384   ViewportSelectionBound viewport_bound;
1385   viewport_bound.type = layer_bound.type;
1386
1387   if (!layer || layer_bound.type == SELECTION_BOUND_EMPTY)
1388     return viewport_bound;
1389
1390   gfx::PointF layer_scaled_top = gfx::ScalePoint(layer_bound.edge_top,
1391                                                  layer->contents_scale_x(),
1392                                                  layer->contents_scale_y());
1393   gfx::PointF layer_scaled_bottom = gfx::ScalePoint(layer_bound.edge_bottom,
1394                                                     layer->contents_scale_x(),
1395                                                     layer->contents_scale_y());
1396
1397   bool clipped = false;
1398   gfx::PointF screen_top = MathUtil::MapPoint(
1399       layer->screen_space_transform(), layer_scaled_top, &clipped);
1400   gfx::PointF screen_bottom = MathUtil::MapPoint(
1401       layer->screen_space_transform(), layer_scaled_bottom, &clipped);
1402
1403   const float inv_scale = 1.f / device_scale_factor;
1404   viewport_bound.edge_top = gfx::ScalePoint(screen_top, inv_scale);
1405   viewport_bound.edge_bottom = gfx::ScalePoint(screen_bottom, inv_scale);
1406
1407   // The bottom edge point is used for visibility testing as it is the logical
1408   // focal point for bound selection handles (this may change in the future).
1409   // Shifting the visibility point fractionally inward ensures that neighboring
1410   // or logically coincident layers aligned to integral DPI coordinates will not
1411   // spuriously occlude the bound.
1412   gfx::Vector2dF visibility_offset = layer_scaled_top - layer_scaled_bottom;
1413   visibility_offset.Scale(device_scale_factor / visibility_offset.Length());
1414   gfx::PointF visibility_point = layer_scaled_bottom + visibility_offset;
1415   if (visibility_point.x() <= 0)
1416     visibility_point.set_x(visibility_point.x() + device_scale_factor);
1417   visibility_point = MathUtil::MapPoint(
1418       layer->screen_space_transform(), visibility_point, &clipped);
1419
1420   float intersect_distance = 0.f;
1421   viewport_bound.visible =
1422       PointHitsLayer(layer, visibility_point, &intersect_distance);
1423
1424   return viewport_bound;
1425 }
1426
1427 void LayerTreeImpl::GetViewportSelection(ViewportSelectionBound* start,
1428                                          ViewportSelectionBound* end) {
1429   DCHECK(start);
1430   DCHECK(end);
1431
1432   *start = ComputeViewportSelection(
1433       selection_start_,
1434       selection_start_.layer_id ? LayerById(selection_start_.layer_id) : NULL,
1435       device_scale_factor());
1436   if (start->type == SELECTION_BOUND_CENTER ||
1437       start->type == SELECTION_BOUND_EMPTY) {
1438     *end = *start;
1439   } else {
1440     *end = ComputeViewportSelection(
1441         selection_end_,
1442         selection_end_.layer_id ? LayerById(selection_end_.layer_id) : NULL,
1443         device_scale_factor());
1444   }
1445 }
1446
1447 void LayerTreeImpl::RegisterPictureLayerImpl(PictureLayerImpl* layer) {
1448   layer_tree_host_impl_->RegisterPictureLayerImpl(layer);
1449 }
1450
1451 void LayerTreeImpl::UnregisterPictureLayerImpl(PictureLayerImpl* layer) {
1452   layer_tree_host_impl_->UnregisterPictureLayerImpl(layer);
1453 }
1454
1455 void LayerTreeImpl::InputScrollAnimationFinished() {
1456   layer_tree_host_impl_->ScrollEnd();
1457 }
1458
1459 BlockingTaskRunner* LayerTreeImpl::BlockingMainThreadTaskRunner() const {
1460   return proxy()->blocking_main_thread_task_runner();
1461 }
1462
1463 void LayerTreeImpl::SetPageScaleAnimation(const gfx::Vector2d& target_offset,
1464                                           bool anchor_point,
1465                                           float page_scale,
1466                                           base::TimeDelta duration) {
1467   if (!InnerViewportScrollLayer())
1468     return;
1469
1470   gfx::Vector2dF scroll_total = TotalScrollOffset();
1471   gfx::SizeF scaled_scrollable_size = ScrollableSize();
1472   gfx::SizeF viewport_size = InnerViewportContainerLayer()->bounds();
1473
1474   // Easing constants experimentally determined.
1475   scoped_ptr<TimingFunction> timing_function =
1476       CubicBezierTimingFunction::Create(.8, 0, .3, .9).PassAs<TimingFunction>();
1477
1478   // TODO(miletus) : Pass in ScrollOffset.
1479   page_scale_animation_ = PageScaleAnimation::Create(scroll_total,
1480                                                      total_page_scale_factor(),
1481                                                      viewport_size,
1482                                                      scaled_scrollable_size,
1483                                                      timing_function.Pass());
1484
1485   if (anchor_point) {
1486     gfx::Vector2dF anchor(target_offset);
1487     page_scale_animation_->ZoomWithAnchor(
1488         anchor, page_scale, duration.InSecondsF());
1489   } else {
1490     gfx::Vector2dF scaled_target_offset = target_offset;
1491     page_scale_animation_->ZoomTo(
1492         scaled_target_offset, page_scale, duration.InSecondsF());
1493   }
1494 }
1495
1496 scoped_ptr<PageScaleAnimation> LayerTreeImpl::TakePageScaleAnimation() {
1497   return page_scale_animation_.Pass();
1498 }
1499
1500 }  // namespace cc