cc/layers/layer.h

   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 #ifndef CC_LAYERS_LAYER_H_
   6 #define CC_LAYERS_LAYER_H_
   7
   8 #include <set>
   9 #include <string>
  10 #include <vector>
  11
  12 #include "base/callback.h"
  13 #include "base/memory/ref_counted.h"
  14 #include "base/observer_list.h"
  15 #include "cc/animation/layer_animation_controller.h"
  16 #include "cc/animation/layer_animation_value_observer.h"
  17 #include "cc/animation/layer_animation_value_provider.h"
  18 #include "cc/base/cc_export.h"
  19 #include "cc/base/region.h"
  20 #include "cc/base/scoped_ptr_vector.h"
  21 #include "cc/debug/frame_timing_request.h"
  22 #include "cc/debug/micro_benchmark.h"
  23 #include "cc/layers/draw_properties.h"
  24 #include "cc/layers/layer_lists.h"
  25 #include "cc/layers/layer_position_constraint.h"
  26 #include "cc/layers/paint_properties.h"
  27 #include "cc/layers/render_surface.h"
  28 #include "cc/layers/scroll_blocks_on.h"
  29 #include "cc/output/filter_operations.h"
  30 #include "cc/trees/property_tree.h"
  31 #include "skia/ext/refptr.h"
  32 #include "third_party/skia/include/core/SkColor.h"
  33 #include "third_party/skia/include/core/SkImageFilter.h"
  34 #include "third_party/skia/include/core/SkPicture.h"
  35 #include "third_party/skia/include/core/SkXfermode.h"
  36 #include "ui/gfx/geometry/point3_f.h"
  37 #include "ui/gfx/geometry/rect.h"
  38 #include "ui/gfx/geometry/rect_f.h"
  39 #include "ui/gfx/geometry/scroll_offset.h"
  40 #include "ui/gfx/transform.h"
  41
  42 namespace gfx {
  43 class BoxF;
  44 }
  45
  46 namespace base {
  47 namespace trace_event {
  48 class ConvertableToTraceFormat;
  49 }
  50 }
  51
  52 namespace cc {
  53
  54 class Animation;
  55 class AnimationDelegate;
  56 struct AnimationEvent;
  57 class CopyOutputRequest;
  58 class LayerAnimationEventObserver;
  59 class LayerClient;
  60 class LayerImpl;
  61 class LayerSettings;
  62 class LayerTreeHost;
  63 class LayerTreeHostCommon;
  64 class LayerTreeImpl;
  65 class LayerTreeSettings;
  66 class RenderingStatsInstrumentation;
  67 class ResourceUpdateQueue;
  68 class ScrollbarLayerInterface;
  69 class SimpleEnclosedRegion;
  70 struct AnimationEvent;
  71
  72 // Base class for composited layers. Special layer types are derived from
  73 // this class.
  74 class CC_EXPORT Layer : public base::RefCounted<Layer>,
  75                         public LayerAnimationValueObserver,
  76                         public LayerAnimationValueProvider {
  77  public:
  78   typedef RenderSurfaceLayerList RenderSurfaceListType;
  79   typedef LayerList LayerListType;
  80   typedef RenderSurface RenderSurfaceType;
  81
  82   enum LayerIdLabels {
  83     INVALID_ID = -1,
  84   };
  85
  86   static scoped_refptr<Layer> Create(const LayerSettings& settings);
  87
  88   int id() const { return layer_id_; }
  89
  90   Layer* RootLayer();
  91   Layer* parent() { return parent_; }
  92   const Layer* parent() const { return parent_; }
  93   void AddChild(scoped_refptr<Layer> child);
  94   void InsertChild(scoped_refptr<Layer> child, size_t index);
  95   void ReplaceChild(Layer* reference, scoped_refptr<Layer> new_layer);
  96   void RemoveFromParent();
  97   void RemoveAllChildren();
  98   void SetChildren(const LayerList& children);
  99   bool HasAncestor(const Layer* ancestor) const;
 100
 101   const LayerList& children() const { return children_; }
 102   Layer* child_at(size_t index) { return children_[index].get(); }
 103
 104   // This requests the layer and its subtree be rendered and given to the
 105   // callback. If the copy is unable to be produced (the layer is destroyed
 106   // first), then the callback is called with a nullptr/empty result. If the
 107   // request's source property is set, any prior uncommitted requests having the
 108   // same source will be aborted.
 109   void RequestCopyOfOutput(scoped_ptr<CopyOutputRequest> request);
 110   bool HasCopyRequest() const {
 111     return !copy_requests_.empty();
 112   }
 113
 114   virtual void SetBackgroundColor(SkColor background_color);
 115   SkColor background_color() const { return background_color_; }
 116   // If contents_opaque(), return an opaque color else return a
 117   // non-opaque color.  Tries to return background_color(), if possible.
 118   SkColor SafeOpaqueBackgroundColor() const;
 119
 120   // A layer's bounds are in logical, non-page-scaled pixels (however, the
 121   // root layer's bounds are in physical pixels).
 122   void SetBounds(const gfx::Size& bounds);
 123   gfx::Size bounds() const { return bounds_; }
 124
 125   void SetMasksToBounds(bool masks_to_bounds);
 126   bool masks_to_bounds() const { return masks_to_bounds_; }
 127
 128   void SetMaskLayer(Layer* mask_layer);
 129   Layer* mask_layer() { return mask_layer_.get(); }
 130   const Layer* mask_layer() const { return mask_layer_.get(); }
 131
 132   virtual void SetNeedsDisplayRect(const gfx::Rect& dirty_rect);
 133   void SetNeedsDisplay() { SetNeedsDisplayRect(gfx::Rect(bounds())); }
 134
 135   void SetOpacity(float opacity);
 136   float opacity() const { return opacity_; }
 137   bool OpacityIsAnimating() const;
 138   bool HasPotentiallyRunningOpacityAnimation() const;
 139   virtual bool OpacityCanAnimateOnImplThread() const;
 140
 141   void SetBlendMode(SkXfermode::Mode blend_mode);
 142   SkXfermode::Mode blend_mode() const { return blend_mode_; }
 143
 144   bool uses_default_blend_mode() const {
 145     return blend_mode_ == SkXfermode::kSrcOver_Mode;
 146   }
 147
 148   // A layer is root for an isolated group when it and all its descendants are
 149   // drawn over a black and fully transparent background, creating an isolated
 150   // group. It should be used along with SetBlendMode(), in order to restrict
 151   // layers within the group to blend with layers outside this group.
 152   void SetIsRootForIsolatedGroup(bool root);
 153   bool is_root_for_isolated_group() const {
 154     return is_root_for_isolated_group_;
 155   }
 156
 157   void SetFilters(const FilterOperations& filters);
 158   const FilterOperations& filters() const { return filters_; }
 159   bool FilterIsAnimating() const;
 160   bool HasPotentiallyRunningFilterAnimation() const;
 161
 162   // Background filters are filters applied to what is behind this layer, when
 163   // they are viewed through non-opaque regions in this layer. They are used
 164   // through the WebLayer interface, and are not exposed to HTML.
 165   void SetBackgroundFilters(const FilterOperations& filters);
 166   const FilterOperations& background_filters() const {
 167     return background_filters_;
 168   }
 169
 170   virtual void SetContentsOpaque(bool opaque);
 171   bool contents_opaque() const { return contents_opaque_; }
 172
 173   void SetPosition(const gfx::PointF& position);
 174   gfx::PointF position() const { return position_; }
 175
 176   // A layer that is a container for fixed position layers cannot be both
 177   // scrollable and have a non-identity transform.
 178   void SetIsContainerForFixedPositionLayers(bool container);
 179   bool IsContainerForFixedPositionLayers() const;
 180
 181   gfx::Vector2dF FixedContainerSizeDelta() const {
 182     return gfx::Vector2dF();
 183   }
 184
 185   void SetPositionConstraint(const LayerPositionConstraint& constraint);
 186   const LayerPositionConstraint& position_constraint() const {
 187     return position_constraint_;
 188   }
 189
 190   void SetTransform(const gfx::Transform& transform);
 191   const gfx::Transform& transform() const { return transform_; }
 192   bool TransformIsAnimating() const;
 193   bool HasPotentiallyRunningTransformAnimation() const;
 194   bool AnimationsPreserveAxisAlignment() const;
 195   bool transform_is_invertible() const { return transform_is_invertible_; }
 196
 197   void SetTransformOrigin(const gfx::Point3F&);
 198   gfx::Point3F transform_origin() const { return transform_origin_; }
 199
 200   bool ScrollOffsetAnimationWasInterrupted() const;
 201
 202   void SetScrollParent(Layer* parent);
 203
 204   Layer* scroll_parent() { return scroll_parent_; }
 205   const Layer* scroll_parent() const { return scroll_parent_; }
 206
 207   void AddScrollChild(Layer* child);
 208   void RemoveScrollChild(Layer* child);
 209
 210   std::set<Layer*>* scroll_children() { return scroll_children_.get(); }
 211   const std::set<Layer*>* scroll_children() const {
 212     return scroll_children_.get();
 213   }
 214
 215   void SetClipParent(Layer* ancestor);
 216
 217   Layer* clip_parent() { return clip_parent_; }
 218   const Layer* clip_parent() const {
 219     return clip_parent_;
 220   }
 221
 222   void AddClipChild(Layer* child);
 223   void RemoveClipChild(Layer* child);
 224
 225   std::set<Layer*>* clip_children() { return clip_children_.get(); }
 226   const std::set<Layer*>* clip_children() const {
 227     return clip_children_.get();
 228   }
 229
 230   DrawProperties<Layer>& draw_properties() { return draw_properties_; }
 231   const DrawProperties<Layer>& draw_properties() const {
 232     return draw_properties_;
 233   }
 234
 235   // The following are shortcut accessors to get various information from
 236   // draw_properties_
 237   const gfx::Transform& draw_transform() const {
 238     return draw_properties_.target_space_transform;
 239   }
 240   const gfx::Transform& screen_space_transform() const {
 241     return draw_properties_.screen_space_transform;
 242   }
 243   float draw_opacity() const { return draw_properties_.opacity; }
 244   bool screen_space_transform_is_animating() const {
 245     return draw_properties_.screen_space_transform_is_animating;
 246   }
 247   gfx::Rect clip_rect() const { return draw_properties_.clip_rect; }
 248   gfx::Rect drawable_content_rect() const {
 249     return draw_properties_.drawable_content_rect;
 250   }
 251   gfx::Rect visible_layer_rect() const {
 252     return draw_properties_.visible_layer_rect;
 253   }
 254   Layer* render_target() {
 255     DCHECK(!draw_properties_.render_target ||
 256            draw_properties_.render_target->render_surface());
 257     return draw_properties_.render_target;
 258   }
 259   const Layer* render_target() const {
 260     DCHECK(!draw_properties_.render_target ||
 261            draw_properties_.render_target->render_surface());
 262     return draw_properties_.render_target;
 263   }
 264   size_t num_unclipped_descendants() const {
 265     return draw_properties_.num_unclipped_descendants;
 266   }
 267
 268   RenderSurface* render_surface() const { return render_surface_.get(); }
 269   void SetScrollOffset(const gfx::ScrollOffset& scroll_offset);
 270   void SetScrollCompensationAdjustment(
 271       const gfx::Vector2dF& scroll_compensation_adjustment);
 272   gfx::Vector2dF ScrollCompensationAdjustment() const;
 273
 274   gfx::ScrollOffset scroll_offset() const { return scroll_offset_; }
 275   void SetScrollOffsetFromImplSide(const gfx::ScrollOffset& scroll_offset);
 276
 277   void SetScrollClipLayerId(int clip_layer_id);
 278   bool scrollable() const { return scroll_clip_layer_id_ != INVALID_ID; }
 279
 280   void SetUserScrollable(bool horizontal, bool vertical);
 281   bool user_scrollable_horizontal() const {
 282     return user_scrollable_horizontal_;
 283   }
 284   bool user_scrollable_vertical() const { return user_scrollable_vertical_; }
 285
 286   void SetShouldScrollOnMainThread(bool should_scroll_on_main_thread);
 287   bool should_scroll_on_main_thread() const {
 288     return should_scroll_on_main_thread_;
 289   }
 290
 291   void SetHaveWheelEventHandlers(bool have_wheel_event_handlers);
 292   bool have_wheel_event_handlers() const { return have_wheel_event_handlers_; }
 293
 294   void SetHaveScrollEventHandlers(bool have_scroll_event_handlers);
 295   bool have_scroll_event_handlers() const {
 296     return have_scroll_event_handlers_;
 297   }
 298
 299   void SetNonFastScrollableRegion(const Region& non_fast_scrollable_region);
 300   const Region& non_fast_scrollable_region() const {
 301     return non_fast_scrollable_region_;
 302   }
 303
 304   void SetTouchEventHandlerRegion(const Region& touch_event_handler_region);
 305   const Region& touch_event_handler_region() const {
 306     return touch_event_handler_region_;
 307   }
 308
 309   void SetScrollBlocksOn(ScrollBlocksOn scroll_blocks_on);
 310   ScrollBlocksOn scroll_blocks_on() const { return scroll_blocks_on_; }
 311
 312   void set_did_scroll_callback(const base::Closure& callback) {
 313     did_scroll_callback_ = callback;
 314   }
 315
 316   void SetDrawCheckerboardForMissingTiles(bool checkerboard);
 317   bool draw_checkerboard_for_missing_tiles() const {
 318     return draw_checkerboard_for_missing_tiles_;
 319   }
 320
 321   void SetForceRenderSurface(bool force_render_surface);
 322   bool force_render_surface() const { return force_render_surface_; }
 323
 324   gfx::Vector2dF ScrollDelta() const { return gfx::Vector2dF(); }
 325   gfx::ScrollOffset CurrentScrollOffset() const { return scroll_offset_; }
 326
 327   void SetDoubleSided(bool double_sided);
 328   bool double_sided() const { return double_sided_; }
 329
 330   void SetShouldFlattenTransform(bool flatten);
 331   bool should_flatten_transform() const { return should_flatten_transform_; }
 332
 333   bool Is3dSorted() const { return sorting_context_id_ != 0; }
 334
 335   void set_use_parent_backface_visibility(bool use) {
 336     use_parent_backface_visibility_ = use;
 337   }
 338   bool use_parent_backface_visibility() const {
 339     return use_parent_backface_visibility_;
 340   }
 341
 342   virtual void SetLayerTreeHost(LayerTreeHost* host);
 343
 344   virtual bool HasDelegatedContent() const;
 345   bool HasContributingDelegatedRenderPasses() const { return false; }
 346
 347   void SetIsDrawable(bool is_drawable);
 348
 349   void SetHideLayerAndSubtree(bool hide);
 350   bool hide_layer_and_subtree() const { return hide_layer_and_subtree_; }
 351
 352   void SetReplicaLayer(Layer* layer);
 353   Layer* replica_layer() { return replica_layer_.get(); }
 354   const Layer* replica_layer() const { return replica_layer_.get(); }
 355
 356   bool has_mask() const { return !!mask_layer_.get(); }
 357   bool has_replica() const { return !!replica_layer_.get(); }
 358   bool replica_has_mask() const {
 359     return replica_layer_.get() &&
 360            (mask_layer_.get() || replica_layer_->mask_layer_.get());
 361   }
 362
 363   int NumDescendantsThatDrawContent() const;
 364
 365   // This is only virtual for tests.
 366   // TODO(awoloszyn): Remove this once we no longer need it for tests
 367   virtual bool DrawsContent() const;
 368
 369   // This methods typically need to be overwritten by derived classes.
 370   virtual void SavePaintProperties();
 371   // Returns true iff anything was updated that needs to be committed.
 372   virtual bool Update();
 373   virtual bool NeedMoreUpdates();
 374   virtual void SetIsMask(bool is_mask) {}
 375   virtual void ReduceMemoryUsage() {}
 376   virtual void OnOutputSurfaceCreated() {}
 377   virtual bool IsSuitableForGpuRasterization() const;
 378
 379   virtual scoped_refptr<base::trace_event::ConvertableToTraceFormat>
 380   TakeDebugInfo();
 381
 382   void SetLayerClient(LayerClient* client) { client_ = client; }
 383
 384   virtual void PushPropertiesTo(LayerImpl* layer);
 385
 386   void CreateRenderSurface();
 387   void ClearRenderSurface();
 388
 389   void ClearRenderSurfaceLayerList();
 390
 391   LayerTreeHost* layer_tree_host() { return layer_tree_host_; }
 392   const LayerTreeHost* layer_tree_host() const { return layer_tree_host_; }
 393
 394   bool AddAnimation(scoped_ptr<Animation> animation);
 395   void PauseAnimation(int animation_id, double time_offset);
 396   void RemoveAnimation(int animation_id);
 397   void RemoveAnimation(int animation_id, Animation::TargetProperty property);
 398   LayerAnimationController* layer_animation_controller() const {
 399     return layer_animation_controller_.get();
 400   }
 401   void SetLayerAnimationControllerForTest(
 402       scoped_refptr<LayerAnimationController> controller);
 403
 404   void set_layer_animation_delegate(AnimationDelegate* delegate) {
 405     DCHECK(layer_animation_controller_);
 406     layer_animation_controller_->set_layer_animation_delegate(delegate);
 407   }
 408
 409   bool HasActiveAnimation() const;
 410   void RegisterForAnimations(AnimationRegistrar* registrar);
 411
 412   void AddLayerAnimationEventObserver(
 413       LayerAnimationEventObserver* animation_observer);
 414   void RemoveLayerAnimationEventObserver(
 415       LayerAnimationEventObserver* animation_observer);
 416
 417   virtual ScrollbarLayerInterface* ToScrollbarLayer();
 418
 419   virtual skia::RefPtr<SkPicture> GetPicture() const;
 420
 421   // Constructs a LayerImpl of the correct runtime type for this Layer type.
 422   virtual scoped_ptr<LayerImpl> CreateLayerImpl(LayerTreeImpl* tree_impl);
 423
 424   bool NeedsDisplayForTesting() const { return !update_rect_.IsEmpty(); }
 425   void ResetNeedsDisplayForTesting() { update_rect_ = gfx::Rect(); }
 426
 427   RenderingStatsInstrumentation* rendering_stats_instrumentation() const;
 428
 429   const PaintProperties& paint_properties() const {
 430     return paint_properties_;
 431   }
 432
 433   void SetNeedsPushProperties();
 434   bool needs_push_properties() const { return needs_push_properties_; }
 435   bool descendant_needs_push_properties() const {
 436     return num_dependents_need_push_properties_ > 0;
 437   }
 438   void reset_needs_push_properties_for_testing() {
 439     needs_push_properties_ = false;
 440   }
 441
 442   virtual void RunMicroBenchmark(MicroBenchmark* benchmark);
 443
 444   void Set3dSortingContextId(int id);
 445   int sorting_context_id() const { return sorting_context_id_; }
 446
 447   void set_property_tree_sequence_number(int sequence_number) {
 448     property_tree_sequence_number_ = sequence_number;
 449   }
 450
 451   void SetTransformTreeIndex(int index);
 452   int transform_tree_index() const;
 453
 454   void SetClipTreeIndex(int index);
 455   int clip_tree_index() const;
 456
 457   void SetOpacityTreeIndex(int index);
 458   int opacity_tree_index() const;
 459
 460   void set_offset_to_transform_parent(gfx::Vector2dF offset) {
 461     if (offset_to_transform_parent_ == offset)
 462       return;
 463     offset_to_transform_parent_ = offset;
 464     SetNeedsPushProperties();
 465   }
 466   gfx::Vector2dF offset_to_transform_parent() const {
 467     return offset_to_transform_parent_;
 468   }
 469
 470   // TODO(vollick): Once we transition to transform and clip trees, rename these
 471   // functions and related values.  The "from property trees" functions below
 472   // use the transform and clip trees.  Eventually, we will use these functions
 473   // to compute the official values, but these functions are retained for
 474   // testing purposes until we've migrated.
 475
 476   const gfx::Rect& visible_rect_from_property_trees() const {
 477     return visible_rect_from_property_trees_;
 478   }
 479   void set_visible_rect_from_property_trees(const gfx::Rect& rect) {
 480     // No push properties here, as this acts like a draw property.
 481     visible_rect_from_property_trees_ = rect;
 482   }
 483
 484   void set_should_flatten_transform_from_property_tree(bool should_flatten) {
 485     if (should_flatten_transform_from_property_tree_ == should_flatten)
 486       return;
 487     should_flatten_transform_from_property_tree_ = should_flatten;
 488     SetNeedsPushProperties();
 489   }
 490   bool should_flatten_transform_from_property_tree() const {
 491     return should_flatten_transform_from_property_tree_;
 492   }
 493
 494   void set_is_clipped(bool is_clipped) {
 495     if (is_clipped_ == is_clipped)
 496       return;
 497     is_clipped_ = is_clipped;
 498     SetNeedsPushProperties();
 499   }
 500   bool is_clipped() const { return is_clipped_; }
 501
 502   // TODO(vollick): These values are temporary and will be removed as soon as
 503   // render surface determinations are moved out of CDP. They only exist because
 504   // certain logic depends on whether or not a layer would render to a separate
 505   // surface, but CDP destroys surfaces and targets it doesn't need, so without
 506   // this boolean, this is impossible to determine after the fact without
 507   // wastefully recomputing it. This is public for the time being so that it can
 508   // be accessed from CDP.
 509   bool has_render_surface() const {
 510     return has_render_surface_;
 511   }
 512
 513   // Sets new frame timing requests for this layer.
 514   void SetFrameTimingRequests(const std::vector<FrameTimingRequest>& requests);
 515
 516   // Accessor for unit tests
 517   const std::vector<FrameTimingRequest>& FrameTimingRequests() const {
 518     return frame_timing_requests_;
 519   }
 520
 521   void DidBeginTracing();
 522   void set_num_layer_or_descandant_with_copy_request(
 523       int num_layer_or_descendants_with_copy_request) {
 524     num_layer_or_descendants_with_copy_request_ =
 525         num_layer_or_descendants_with_copy_request;
 526   }
 527
 528   void set_num_layer_or_descandant_with_input_handler(
 529       int num_layer_or_descendants_with_input_handler) {
 530     num_layer_or_descendants_with_input_handler_ =
 531         num_layer_or_descendants_with_input_handler;
 532   }
 533
 534   int num_layer_or_descendants_with_input_handler() {
 535     return num_layer_or_descendants_with_input_handler_;
 536   }
 537
 538   void set_num_children_with_scroll_parent(
 539       int num_children_with_scroll_parent) {
 540     num_children_with_scroll_parent_ = num_children_with_scroll_parent;
 541   }
 542
 543   int num_children_with_scroll_parent() {
 544     return num_children_with_scroll_parent_;
 545   }
 546
 547   void set_visited(bool visited);
 548   bool visited();
 549   void set_layer_or_descendant_is_drawn(bool layer_or_descendant_is_drawn);
 550   bool layer_or_descendant_is_drawn();
 551   void set_sorted_for_recursion(bool sorted_for_recursion);
 552   bool sorted_for_recursion();
 553
 554  protected:
 555   friend class LayerImpl;
 556   friend class TreeSynchronizer;
 557   ~Layer() override;
 558
 559   explicit Layer(const LayerSettings& settings);
 560
 561   // These SetNeeds functions are in order of severity of update:
 562   //
 563   // Called when this layer has been modified in some way, but isn't sure
 564   // that it needs a commit yet.  It needs CalcDrawProperties and UpdateLayers
 565   // before it knows whether or not a commit is required.
 566   void SetNeedsUpdate();
 567   // Called when a property has been modified in a way that the layer
 568   // knows immediately that a commit is required.  This implies SetNeedsUpdate
 569   // as well as SetNeedsPushProperties to push that property.
 570   void SetNeedsCommit();
 571   // This is identical to SetNeedsCommit, but the former requests a rebuild of
 572   // the property trees.
 573   void SetNeedsCommitNoRebuild();
 574   // Called when there's been a change in layer structure.  Implies both
 575   // SetNeedsUpdate and SetNeedsCommit, but not SetNeedsPushProperties.
 576   void SetNeedsFullTreeSync();
 577
 578   // Called when the next commit should wait until the pending tree is activated
 579   // before finishing the commit and unblocking the main thread. Used to ensure
 580   // unused resources on the impl thread are returned before commit completes.
 581   void SetNextCommitWaitsForActivation();
 582
 583   // Will recalculate whether the layer draws content and set draws_content_
 584   // appropriately.
 585   void UpdateDrawsContent(bool has_drawable_content);
 586   virtual bool HasDrawableContent() const;
 587
 588   // Called when the layer's number of drawable descendants changes.
 589   void AddDrawableDescendants(int num);
 590
 591   void AddDependentNeedsPushProperties();
 592   void RemoveDependentNeedsPushProperties();
 593   bool parent_should_know_need_push_properties() const {
 594     return needs_push_properties() || descendant_needs_push_properties();
 595   }
 596
 597   bool IsPropertyChangeAllowed() const;
 598
 599   // This flag is set when the layer needs to push properties to the impl
 600   // side.
 601   bool needs_push_properties_;
 602
 603   // The number of direct children or dependent layers that need to be recursed
 604   // to in order for them or a descendent of them to push properties to the impl
 605   // side.
 606   int num_dependents_need_push_properties_;
 607
 608   // Tracks whether this layer may have changed stacking order with its
 609   // siblings.
 610   bool stacking_order_changed_;
 611
 612   // The update rect is the region of the compositor resource that was
 613   // actually updated by the compositor. For layers that may do updating
 614   // outside the compositor's control (i.e. plugin layers), this information
 615   // is not available and the update rect will remain empty.
 616   // Note this rect is in layer space (not content space).
 617   gfx::Rect update_rect_;
 618
 619   scoped_refptr<Layer> mask_layer_;
 620
 621   int layer_id_;
 622
 623   // When true, the layer is about to perform an update. Any commit requests
 624   // will be handled implicitly after the update completes.
 625   bool ignore_set_needs_commit_;
 626
 627   // Layers that share a sorting context id will be sorted together in 3d
 628   // space.  0 is a special value that means this layer will not be sorted and
 629   // will be drawn in paint order.
 630   int sorting_context_id_;
 631
 632  private:
 633   friend class base::RefCounted<Layer>;
 634   friend class LayerTreeHostCommon;
 635   void SetParent(Layer* layer);
 636   bool DescendantIsFixedToContainerLayer() const;
 637
 638   // This should only be called during BeginMainFrame since it does not
 639   // trigger a Commit.
 640   void SetHasRenderSurface(bool has_render_surface);
 641
 642   // This should only be called from RemoveFromParent().
 643   void RemoveChildOrDependent(Layer* child);
 644
 645   // LayerAnimationValueProvider implementation.
 646   gfx::ScrollOffset ScrollOffsetForAnimation() const override;
 647
 648   // LayerAnimationValueObserver implementation.
 649   void OnFilterAnimated(const FilterOperations& filters) override;
 650   void OnOpacityAnimated(float opacity) override;
 651   void OnTransformAnimated(const gfx::Transform& transform) override;
 652   void OnScrollOffsetAnimated(const gfx::ScrollOffset& scroll_offset) override;
 653   void OnAnimationWaitingForDeletion() override;
 654   bool IsActive() const override;
 655
 656   // If this layer has a scroll parent, it removes |this| from its list of
 657   // scroll children.
 658   void RemoveFromScrollTree();
 659
 660   // If this layer has a clip parent, it removes |this| from its list of clip
 661   // children.
 662   void RemoveFromClipTree();
 663
 664   // When we detach or attach layer to new LayerTreeHost, all property trees'
 665   // indices becomes invalid.
 666   void InvalidatePropertyTreesIndices();
 667
 668   void UpdateNumCopyRequestsForSubtree(bool add);
 669   void UpdateNumInputHandlersForSubtree(bool add);
 670
 671   LayerList children_;
 672   Layer* parent_;
 673
 674   // Layer instances have a weak pointer to their LayerTreeHost.
 675   // This pointer value is nil when a Layer is not in a tree and is
 676   // updated via SetLayerTreeHost() if a layer moves between trees.
 677   LayerTreeHost* layer_tree_host_;
 678
 679   scoped_refptr<LayerAnimationController> layer_animation_controller_;
 680
 681   // Layer properties.
 682   gfx::Size bounds_;
 683
 684   gfx::ScrollOffset scroll_offset_;
 685   gfx::Vector2dF scroll_compensation_adjustment_;
 686   // This variable indicates which ancestor layer (if any) whose size,
 687   // transformed relative to this layer, defines the maximum scroll offset for
 688   // this layer.
 689   int scroll_clip_layer_id_;
 690   int num_descendants_that_draw_content_;
 691   int transform_tree_index_;
 692   int opacity_tree_index_;
 693   int clip_tree_index_;
 694   int property_tree_sequence_number_;
 695   int num_layer_or_descendants_with_copy_request_;
 696   int num_layer_or_descendants_with_input_handler_;
 697   int num_children_with_scroll_parent_;
 698   gfx::Vector2dF offset_to_transform_parent_;
 699   bool should_flatten_transform_from_property_tree_ : 1;
 700   bool is_clipped_ : 1;
 701   bool should_scroll_on_main_thread_ : 1;
 702   bool have_wheel_event_handlers_ : 1;
 703   bool have_scroll_event_handlers_ : 1;
 704   bool user_scrollable_horizontal_ : 1;
 705   bool user_scrollable_vertical_ : 1;
 706   bool is_root_for_isolated_group_ : 1;
 707   bool is_container_for_fixed_position_layers_ : 1;
 708   bool is_drawable_ : 1;
 709   bool draws_content_ : 1;
 710   bool hide_layer_and_subtree_ : 1;
 711   bool masks_to_bounds_ : 1;
 712   bool contents_opaque_ : 1;
 713   bool double_sided_ : 1;
 714   bool should_flatten_transform_ : 1;
 715   bool use_parent_backface_visibility_ : 1;
 716   bool draw_checkerboard_for_missing_tiles_ : 1;
 717   bool force_render_surface_ : 1;
 718   bool transform_is_invertible_ : 1;
 719   bool has_render_surface_ : 1;
 720   ScrollBlocksOn scroll_blocks_on_ : 3;
 721   Region non_fast_scrollable_region_;
 722   Region touch_event_handler_region_;
 723   gfx::PointF position_;
 724   SkColor background_color_;
 725   float opacity_;
 726   SkXfermode::Mode blend_mode_;
 727   FilterOperations filters_;
 728   FilterOperations background_filters_;
 729   LayerPositionConstraint position_constraint_;
 730   Layer* scroll_parent_;
 731   scoped_ptr<std::set<Layer*>> scroll_children_;
 732
 733   // The following three variables are tracker variables. They are bools
 734   // wrapped inside an integer variable. If true, their value equals the
 735   // LayerTreeHost's meta_information_sequence_number. This wrapping of bools
 736   // inside ints is done to avoid a layer tree treewalk to reset their values.
 737   int layer_or_descendant_is_drawn_tracker_;
 738   int sorted_for_recursion_tracker_;
 739   int visited_tracker_;
 740
 741   Layer* clip_parent_;
 742   scoped_ptr<std::set<Layer*>> clip_children_;
 743
 744   gfx::Transform transform_;
 745   gfx::Point3F transform_origin_;
 746
 747   // Replica layer used for reflections.
 748   scoped_refptr<Layer> replica_layer_;
 749
 750   LayerClient* client_;
 751
 752   ScopedPtrVector<CopyOutputRequest> copy_requests_;
 753
 754   base::Closure did_scroll_callback_;
 755
 756   DrawProperties<Layer> draw_properties_;
 757
 758   PaintProperties paint_properties_;
 759   // TODO(awoloszyn): This is redundant with has_render_surface_,
 760   // and should get removed once it is no longer needed on main thread.
 761   scoped_ptr<RenderSurface> render_surface_;
 762
 763   gfx::Rect visible_rect_from_property_trees_;
 764
 765   std::vector<FrameTimingRequest> frame_timing_requests_;
 766   bool frame_timing_requests_dirty_;
 767
 768   DISALLOW_COPY_AND_ASSIGN(Layer);
 769 };
 770
 771 }  // namespace cc
 772
 773 #endif  // CC_LAYERS_LAYER_H_