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 HasAnyAnimationTargetingProperty(
 201       Animation::TargetProperty property) const;
 202
 203   bool ScrollOffsetAnimationWasInterrupted() const;
 204
 205   void SetScrollParent(Layer* parent);
 206
 207   Layer* scroll_parent() { return scroll_parent_; }
 208   const Layer* scroll_parent() const { return scroll_parent_; }
 209
 210   void AddScrollChild(Layer* child);
 211   void RemoveScrollChild(Layer* child);
 212
 213   std::set<Layer*>* scroll_children() { return scroll_children_.get(); }
 214   const std::set<Layer*>* scroll_children() const {
 215     return scroll_children_.get();
 216   }
 217
 218   void SetClipParent(Layer* ancestor);
 219
 220   Layer* clip_parent() { return clip_parent_; }
 221   const Layer* clip_parent() const {
 222     return clip_parent_;
 223   }
 224
 225   void AddClipChild(Layer* child);
 226   void RemoveClipChild(Layer* child);
 227
 228   std::set<Layer*>* clip_children() { return clip_children_.get(); }
 229   const std::set<Layer*>* clip_children() const {
 230     return clip_children_.get();
 231   }
 232
 233   DrawProperties<Layer>& draw_properties() { return draw_properties_; }
 234   const DrawProperties<Layer>& draw_properties() const {
 235     return draw_properties_;
 236   }
 237
 238   // The following are shortcut accessors to get various information from
 239   // draw_properties_
 240   const gfx::Transform& draw_transform() const {
 241     return draw_properties_.target_space_transform;
 242   }
 243   const gfx::Transform& screen_space_transform() const {
 244     return draw_properties_.screen_space_transform;
 245   }
 246   float draw_opacity() const { return draw_properties_.opacity; }
 247   bool screen_space_transform_is_animating() const {
 248     return draw_properties_.screen_space_transform_is_animating;
 249   }
 250   gfx::Rect clip_rect() const { return draw_properties_.clip_rect; }
 251   gfx::Rect drawable_content_rect() const {
 252     return draw_properties_.drawable_content_rect;
 253   }
 254   gfx::Rect visible_layer_rect() const {
 255     return draw_properties_.visible_layer_rect;
 256   }
 257   Layer* render_target() {
 258     DCHECK(!draw_properties_.render_target ||
 259            draw_properties_.render_target->render_surface());
 260     return draw_properties_.render_target;
 261   }
 262   const Layer* render_target() const {
 263     DCHECK(!draw_properties_.render_target ||
 264            draw_properties_.render_target->render_surface());
 265     return draw_properties_.render_target;
 266   }
 267   size_t num_unclipped_descendants() const {
 268     return draw_properties_.num_unclipped_descendants;
 269   }
 270
 271   RenderSurface* render_surface() const { return render_surface_.get(); }
 272   void SetScrollOffset(const gfx::ScrollOffset& scroll_offset);
 273   void SetScrollCompensationAdjustment(
 274       const gfx::Vector2dF& scroll_compensation_adjustment);
 275   gfx::Vector2dF ScrollCompensationAdjustment() const;
 276
 277   gfx::ScrollOffset scroll_offset() const { return scroll_offset_; }
 278   void SetScrollOffsetFromImplSide(const gfx::ScrollOffset& scroll_offset);
 279
 280   void SetScrollClipLayerId(int clip_layer_id);
 281   bool scrollable() const { return scroll_clip_layer_id_ != INVALID_ID; }
 282
 283   void SetUserScrollable(bool horizontal, bool vertical);
 284   bool user_scrollable_horizontal() const {
 285     return user_scrollable_horizontal_;
 286   }
 287   bool user_scrollable_vertical() const { return user_scrollable_vertical_; }
 288
 289   void SetShouldScrollOnMainThread(bool should_scroll_on_main_thread);
 290   bool should_scroll_on_main_thread() const {
 291     return should_scroll_on_main_thread_;
 292   }
 293
 294   void SetHaveWheelEventHandlers(bool have_wheel_event_handlers);
 295   bool have_wheel_event_handlers() const { return have_wheel_event_handlers_; }
 296
 297   void SetHaveScrollEventHandlers(bool have_scroll_event_handlers);
 298   bool have_scroll_event_handlers() const {
 299     return have_scroll_event_handlers_;
 300   }
 301
 302   void SetNonFastScrollableRegion(const Region& non_fast_scrollable_region);
 303   const Region& non_fast_scrollable_region() const {
 304     return non_fast_scrollable_region_;
 305   }
 306
 307   void SetTouchEventHandlerRegion(const Region& touch_event_handler_region);
 308   const Region& touch_event_handler_region() const {
 309     return touch_event_handler_region_;
 310   }
 311
 312   void SetScrollBlocksOn(ScrollBlocksOn scroll_blocks_on);
 313   ScrollBlocksOn scroll_blocks_on() const { return scroll_blocks_on_; }
 314
 315   void set_did_scroll_callback(const base::Closure& callback) {
 316     did_scroll_callback_ = callback;
 317   }
 318
 319   void SetForceRenderSurface(bool force_render_surface);
 320   bool force_render_surface() const { return force_render_surface_; }
 321
 322   gfx::Vector2dF ScrollDelta() const { return gfx::Vector2dF(); }
 323   gfx::ScrollOffset CurrentScrollOffset() const { return scroll_offset_; }
 324
 325   void SetDoubleSided(bool double_sided);
 326   bool double_sided() const { return double_sided_; }
 327
 328   void SetShouldFlattenTransform(bool flatten);
 329   bool should_flatten_transform() const { return should_flatten_transform_; }
 330
 331   bool Is3dSorted() const { return sorting_context_id_ != 0; }
 332
 333   void set_use_parent_backface_visibility(bool use) {
 334     use_parent_backface_visibility_ = use;
 335   }
 336   bool use_parent_backface_visibility() const {
 337     return use_parent_backface_visibility_;
 338   }
 339
 340   virtual void SetLayerTreeHost(LayerTreeHost* host);
 341
 342   virtual bool HasDelegatedContent() const;
 343   bool HasContributingDelegatedRenderPasses() const { return false; }
 344
 345   void SetIsDrawable(bool is_drawable);
 346
 347   void SetHideLayerAndSubtree(bool hide);
 348   bool hide_layer_and_subtree() const { return hide_layer_and_subtree_; }
 349
 350   void SetReplicaLayer(Layer* layer);
 351   Layer* replica_layer() { return replica_layer_.get(); }
 352   const Layer* replica_layer() const { return replica_layer_.get(); }
 353
 354   bool has_mask() const { return !!mask_layer_.get(); }
 355   bool has_replica() const { return !!replica_layer_.get(); }
 356   bool replica_has_mask() const {
 357     return replica_layer_.get() &&
 358            (mask_layer_.get() || replica_layer_->mask_layer_.get());
 359   }
 360
 361   int NumDescendantsThatDrawContent() const;
 362
 363   // This is only virtual for tests.
 364   // TODO(awoloszyn): Remove this once we no longer need it for tests
 365   virtual bool DrawsContent() const;
 366
 367   // This methods typically need to be overwritten by derived classes.
 368   virtual void SavePaintProperties();
 369   // Returns true iff anything was updated that needs to be committed.
 370   virtual bool Update();
 371   virtual bool NeedMoreUpdates();
 372   virtual void SetIsMask(bool is_mask) {}
 373   virtual void ReduceMemoryUsage() {}
 374   virtual void OnOutputSurfaceCreated() {}
 375   virtual bool IsSuitableForGpuRasterization() const;
 376
 377   virtual scoped_refptr<base::trace_event::ConvertableToTraceFormat>
 378   TakeDebugInfo();
 379
 380   void SetLayerClient(LayerClient* client) { client_ = client; }
 381
 382   virtual void PushPropertiesTo(LayerImpl* layer);
 383
 384   void CreateRenderSurface();
 385   void ClearRenderSurface();
 386
 387   void ClearRenderSurfaceLayerList();
 388
 389   LayerTreeHost* layer_tree_host() { return layer_tree_host_; }
 390   const LayerTreeHost* layer_tree_host() const { return layer_tree_host_; }
 391
 392   bool AddAnimation(scoped_ptr<Animation> animation);
 393   void PauseAnimation(int animation_id, double time_offset);
 394   void RemoveAnimation(int animation_id);
 395   void RemoveAnimation(int animation_id, Animation::TargetProperty property);
 396   LayerAnimationController* layer_animation_controller() const {
 397     return layer_animation_controller_.get();
 398   }
 399   void SetLayerAnimationControllerForTest(
 400       scoped_refptr<LayerAnimationController> controller);
 401
 402   void set_layer_animation_delegate(AnimationDelegate* delegate) {
 403     DCHECK(layer_animation_controller_);
 404     layer_animation_controller_->set_layer_animation_delegate(delegate);
 405   }
 406
 407   bool HasActiveAnimation() const;
 408   void RegisterForAnimations(AnimationRegistrar* registrar);
 409
 410   void AddLayerAnimationEventObserver(
 411       LayerAnimationEventObserver* animation_observer);
 412   void RemoveLayerAnimationEventObserver(
 413       LayerAnimationEventObserver* animation_observer);
 414
 415   virtual ScrollbarLayerInterface* ToScrollbarLayer();
 416
 417   virtual skia::RefPtr<SkPicture> GetPicture() const;
 418
 419   // Constructs a LayerImpl of the correct runtime type for this Layer type.
 420   virtual scoped_ptr<LayerImpl> CreateLayerImpl(LayerTreeImpl* tree_impl);
 421
 422   bool NeedsDisplayForTesting() const { return !update_rect_.IsEmpty(); }
 423   void ResetNeedsDisplayForTesting() { update_rect_ = gfx::Rect(); }
 424
 425   RenderingStatsInstrumentation* rendering_stats_instrumentation() const;
 426
 427   const PaintProperties& paint_properties() const {
 428     return paint_properties_;
 429   }
 430
 431   void SetNeedsPushProperties();
 432   bool needs_push_properties() const { return needs_push_properties_; }
 433   bool descendant_needs_push_properties() const {
 434     return num_dependents_need_push_properties_ > 0;
 435   }
 436   void reset_needs_push_properties_for_testing() {
 437     needs_push_properties_ = false;
 438   }
 439
 440   virtual void RunMicroBenchmark(MicroBenchmark* benchmark);
 441
 442   void Set3dSortingContextId(int id);
 443   int sorting_context_id() const { return sorting_context_id_; }
 444
 445   void set_property_tree_sequence_number(int sequence_number) {
 446     property_tree_sequence_number_ = sequence_number;
 447   }
 448
 449   void SetTransformTreeIndex(int index);
 450   int transform_tree_index() const;
 451
 452   void SetClipTreeIndex(int index);
 453   int clip_tree_index() const;
 454
 455   void SetOpacityTreeIndex(int index);
 456   int opacity_tree_index() const;
 457
 458   void set_offset_to_transform_parent(gfx::Vector2dF offset) {
 459     if (offset_to_transform_parent_ == offset)
 460       return;
 461     offset_to_transform_parent_ = offset;
 462     SetNeedsPushProperties();
 463   }
 464   gfx::Vector2dF offset_to_transform_parent() const {
 465     return offset_to_transform_parent_;
 466   }
 467
 468   // TODO(vollick): Once we transition to transform and clip trees, rename these
 469   // functions and related values.  The "from property trees" functions below
 470   // use the transform and clip trees.  Eventually, we will use these functions
 471   // to compute the official values, but these functions are retained for
 472   // testing purposes until we've migrated.
 473
 474   const gfx::Rect& visible_rect_from_property_trees() const {
 475     return visible_rect_from_property_trees_;
 476   }
 477   void set_visible_rect_from_property_trees(const gfx::Rect& rect) {
 478     // No push properties here, as this acts like a draw property.
 479     visible_rect_from_property_trees_ = rect;
 480   }
 481
 482   const gfx::Rect& clip_rect_in_target_space_from_property_trees() const {
 483     return clip_rect_in_target_space_from_property_trees_;
 484   }
 485   void set_clip_rect_in_target_space_from_property_trees(
 486       const gfx::Rect& rect) {
 487     clip_rect_in_target_space_from_property_trees_ = rect;
 488   }
 489
 490   void set_should_flatten_transform_from_property_tree(bool should_flatten) {
 491     if (should_flatten_transform_from_property_tree_ == should_flatten)
 492       return;
 493     should_flatten_transform_from_property_tree_ = should_flatten;
 494     SetNeedsPushProperties();
 495   }
 496   bool should_flatten_transform_from_property_tree() const {
 497     return should_flatten_transform_from_property_tree_;
 498   }
 499
 500   void set_is_clipped(bool is_clipped) {
 501     if (is_clipped_ == is_clipped)
 502       return;
 503     is_clipped_ = is_clipped;
 504     SetNeedsPushProperties();
 505   }
 506   bool is_clipped() const { return is_clipped_; }
 507
 508   // TODO(vollick): These values are temporary and will be removed as soon as
 509   // render surface determinations are moved out of CDP. They only exist because
 510   // certain logic depends on whether or not a layer would render to a separate
 511   // surface, but CDP destroys surfaces and targets it doesn't need, so without
 512   // this boolean, this is impossible to determine after the fact without
 513   // wastefully recomputing it. This is public for the time being so that it can
 514   // be accessed from CDP.
 515   bool has_render_surface() const {
 516     return has_render_surface_;
 517   }
 518
 519   // Sets new frame timing requests for this layer.
 520   void SetFrameTimingRequests(const std::vector<FrameTimingRequest>& requests);
 521
 522   // Accessor for unit tests
 523   const std::vector<FrameTimingRequest>& FrameTimingRequests() const {
 524     return frame_timing_requests_;
 525   }
 526
 527   void DidBeginTracing();
 528   void set_num_layer_or_descandant_with_copy_request(
 529       int num_layer_or_descendants_with_copy_request) {
 530     num_layer_or_descendants_with_copy_request_ =
 531         num_layer_or_descendants_with_copy_request;
 532   }
 533
 534   void set_num_layer_or_descandant_with_input_handler(
 535       int num_layer_or_descendants_with_input_handler) {
 536     num_layer_or_descendants_with_input_handler_ =
 537         num_layer_or_descendants_with_input_handler;
 538   }
 539
 540   int num_layer_or_descendants_with_input_handler() {
 541     return num_layer_or_descendants_with_input_handler_;
 542   }
 543
 544   void set_num_children_with_scroll_parent(
 545       int num_children_with_scroll_parent) {
 546     num_children_with_scroll_parent_ = num_children_with_scroll_parent;
 547   }
 548
 549   int num_children_with_scroll_parent() {
 550     return num_children_with_scroll_parent_;
 551   }
 552
 553   void set_visited(bool visited);
 554   bool visited();
 555   void set_layer_or_descendant_is_drawn(bool layer_or_descendant_is_drawn);
 556   bool layer_or_descendant_is_drawn();
 557   void set_sorted_for_recursion(bool sorted_for_recursion);
 558   bool sorted_for_recursion();
 559
 560  protected:
 561   friend class LayerImpl;
 562   friend class TreeSynchronizer;
 563   ~Layer() override;
 564
 565   explicit Layer(const LayerSettings& settings);
 566
 567   // These SetNeeds functions are in order of severity of update:
 568   //
 569   // Called when this layer has been modified in some way, but isn't sure
 570   // that it needs a commit yet.  It needs CalcDrawProperties and UpdateLayers
 571   // before it knows whether or not a commit is required.
 572   void SetNeedsUpdate();
 573   // Called when a property has been modified in a way that the layer
 574   // knows immediately that a commit is required.  This implies SetNeedsUpdate
 575   // as well as SetNeedsPushProperties to push that property.
 576   void SetNeedsCommit();
 577   // This is identical to SetNeedsCommit, but the former requests a rebuild of
 578   // the property trees.
 579   void SetNeedsCommitNoRebuild();
 580   // Called when there's been a change in layer structure.  Implies both
 581   // SetNeedsUpdate and SetNeedsCommit, but not SetNeedsPushProperties.
 582   void SetNeedsFullTreeSync();
 583
 584   // Called when the next commit should wait until the pending tree is activated
 585   // before finishing the commit and unblocking the main thread. Used to ensure
 586   // unused resources on the impl thread are returned before commit completes.
 587   void SetNextCommitWaitsForActivation();
 588
 589   // Will recalculate whether the layer draws content and set draws_content_
 590   // appropriately.
 591   void UpdateDrawsContent(bool has_drawable_content);
 592   virtual bool HasDrawableContent() const;
 593
 594   // Called when the layer's number of drawable descendants changes.
 595   void AddDrawableDescendants(int num);
 596
 597   void AddDependentNeedsPushProperties();
 598   void RemoveDependentNeedsPushProperties();
 599   bool parent_should_know_need_push_properties() const {
 600     return needs_push_properties() || descendant_needs_push_properties();
 601   }
 602
 603   bool IsPropertyChangeAllowed() const;
 604
 605   // This flag is set when the layer needs to push properties to the impl
 606   // side.
 607   bool needs_push_properties_;
 608
 609   // The number of direct children or dependent layers that need to be recursed
 610   // to in order for them or a descendent of them to push properties to the impl
 611   // side.
 612   int num_dependents_need_push_properties_;
 613
 614   // Tracks whether this layer may have changed stacking order with its
 615   // siblings.
 616   bool stacking_order_changed_;
 617
 618   // The update rect is the region of the compositor resource that was
 619   // actually updated by the compositor. For layers that may do updating
 620   // outside the compositor's control (i.e. plugin layers), this information
 621   // is not available and the update rect will remain empty.
 622   // Note this rect is in layer space (not content space).
 623   gfx::Rect update_rect_;
 624
 625   scoped_refptr<Layer> mask_layer_;
 626
 627   int layer_id_;
 628
 629   // When true, the layer is about to perform an update. Any commit requests
 630   // will be handled implicitly after the update completes.
 631   bool ignore_set_needs_commit_;
 632
 633   // Layers that share a sorting context id will be sorted together in 3d
 634   // space.  0 is a special value that means this layer will not be sorted and
 635   // will be drawn in paint order.
 636   int sorting_context_id_;
 637
 638  private:
 639   friend class base::RefCounted<Layer>;
 640   friend class LayerTreeHostCommon;
 641   void SetParent(Layer* layer);
 642   bool DescendantIsFixedToContainerLayer() const;
 643
 644   // This should only be called during BeginMainFrame since it does not
 645   // trigger a Commit.
 646   void SetHasRenderSurface(bool has_render_surface);
 647
 648   // This should only be called from RemoveFromParent().
 649   void RemoveChildOrDependent(Layer* child);
 650
 651   // LayerAnimationValueProvider implementation.
 652   gfx::ScrollOffset ScrollOffsetForAnimation() const override;
 653
 654   // LayerAnimationValueObserver implementation.
 655   void OnFilterAnimated(const FilterOperations& filters) override;
 656   void OnOpacityAnimated(float opacity) override;
 657   void OnTransformAnimated(const gfx::Transform& transform) override;
 658   void OnScrollOffsetAnimated(const gfx::ScrollOffset& scroll_offset) override;
 659   void OnAnimationWaitingForDeletion() override;
 660   void OnTransformIsPotentiallyAnimatingChanged(bool is_animating) 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   // When we detach or attach layer to new LayerTreeHost, all property trees'
 672   // indices becomes invalid.
 673   void InvalidatePropertyTreesIndices();
 674
 675   void UpdateNumCopyRequestsForSubtree(bool add);
 676   void UpdateNumInputHandlersForSubtree(bool add);
 677
 678   LayerList children_;
 679   Layer* parent_;
 680
 681   // Layer instances have a weak pointer to their LayerTreeHost.
 682   // This pointer value is nil when a Layer is not in a tree and is
 683   // updated via SetLayerTreeHost() if a layer moves between trees.
 684   LayerTreeHost* layer_tree_host_;
 685
 686   scoped_refptr<LayerAnimationController> layer_animation_controller_;
 687
 688   // Layer properties.
 689   gfx::Size bounds_;
 690
 691   gfx::ScrollOffset scroll_offset_;
 692   gfx::Vector2dF scroll_compensation_adjustment_;
 693   // This variable indicates which ancestor layer (if any) whose size,
 694   // transformed relative to this layer, defines the maximum scroll offset for
 695   // this layer.
 696   int scroll_clip_layer_id_;
 697   int num_descendants_that_draw_content_;
 698   int transform_tree_index_;
 699   int opacity_tree_index_;
 700   int clip_tree_index_;
 701   int property_tree_sequence_number_;
 702   int num_layer_or_descendants_with_copy_request_;
 703   int num_layer_or_descendants_with_input_handler_;
 704   int num_children_with_scroll_parent_;
 705   gfx::Vector2dF offset_to_transform_parent_;
 706   bool should_flatten_transform_from_property_tree_ : 1;
 707   bool is_clipped_ : 1;
 708   bool should_scroll_on_main_thread_ : 1;
 709   bool have_wheel_event_handlers_ : 1;
 710   bool have_scroll_event_handlers_ : 1;
 711   bool user_scrollable_horizontal_ : 1;
 712   bool user_scrollable_vertical_ : 1;
 713   bool is_root_for_isolated_group_ : 1;
 714   bool is_container_for_fixed_position_layers_ : 1;
 715   bool is_drawable_ : 1;
 716   bool draws_content_ : 1;
 717   bool hide_layer_and_subtree_ : 1;
 718   bool masks_to_bounds_ : 1;
 719   bool contents_opaque_ : 1;
 720   bool double_sided_ : 1;
 721   bool should_flatten_transform_ : 1;
 722   bool use_parent_backface_visibility_ : 1;
 723   bool force_render_surface_ : 1;
 724   bool transform_is_invertible_ : 1;
 725   bool has_render_surface_ : 1;
 726   ScrollBlocksOn scroll_blocks_on_ : 3;
 727   Region non_fast_scrollable_region_;
 728   Region touch_event_handler_region_;
 729   gfx::PointF position_;
 730   SkColor background_color_;
 731   float opacity_;
 732   SkXfermode::Mode blend_mode_;
 733   FilterOperations filters_;
 734   FilterOperations background_filters_;
 735   LayerPositionConstraint position_constraint_;
 736   Layer* scroll_parent_;
 737   scoped_ptr<std::set<Layer*>> scroll_children_;
 738
 739   // The following three variables are tracker variables. They are bools
 740   // wrapped inside an integer variable. If true, their value equals the
 741   // LayerTreeHost's meta_information_sequence_number. This wrapping of bools
 742   // inside ints is done to avoid a layer tree treewalk to reset their values.
 743   int layer_or_descendant_is_drawn_tracker_;
 744   int sorted_for_recursion_tracker_;
 745   int visited_tracker_;
 746
 747   Layer* clip_parent_;
 748   scoped_ptr<std::set<Layer*>> clip_children_;
 749
 750   gfx::Transform transform_;
 751   gfx::Point3F transform_origin_;
 752
 753   // Replica layer used for reflections.
 754   scoped_refptr<Layer> replica_layer_;
 755
 756   LayerClient* client_;
 757
 758   ScopedPtrVector<CopyOutputRequest> copy_requests_;
 759
 760   base::Closure did_scroll_callback_;
 761
 762   DrawProperties<Layer> draw_properties_;
 763
 764   PaintProperties paint_properties_;
 765   // TODO(awoloszyn): This is redundant with has_render_surface_,
 766   // and should get removed once it is no longer needed on main thread.
 767   scoped_ptr<RenderSurface> render_surface_;
 768
 769   gfx::Rect visible_rect_from_property_trees_;
 770   gfx::Rect clip_rect_in_target_space_from_property_trees_;
 771
 772   std::vector<FrameTimingRequest> frame_timing_requests_;
 773   bool frame_timing_requests_dirty_;
 774
 775   DISALLOW_COPY_AND_ASSIGN(Layer);
 776 };
 777
 778 }  // namespace cc
 779
 780 #endif  // CC_LAYERS_LAYER_H_