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