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