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 PriorityCalculator;
  67 class RenderingStatsInstrumentation;
  68 class ResourceUpdateQueue;
  69 class ScrollbarLayerInterface;
  70 class SimpleEnclosedRegion;
  71 struct AnimationEvent;
  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(const LayerSettings& settings);
  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   // A layer that is a container for fixed position layers cannot be both
 176   // scrollable and have a non-identity transform.
 177   void SetIsContainerForFixedPositionLayers(bool container);
 178   bool IsContainerForFixedPositionLayers() const;
 179
 180   gfx::Vector2dF FixedContainerSizeDelta() const {
 181     return gfx::Vector2dF();
 182   }
 183
 184   void SetPositionConstraint(const LayerPositionConstraint& constraint);
 185   const LayerPositionConstraint& position_constraint() const {
 186     return position_constraint_;
 187   }
 188
 189   void SetTransform(const gfx::Transform& transform);
 190   const gfx::Transform& transform() const { return transform_; }
 191   bool TransformIsAnimating() const;
 192   bool AnimationsPreserveAxisAlignment() const;
 193   bool transform_is_invertible() const { return transform_is_invertible_; }
 194
 195   void SetTransformOrigin(const gfx::Point3F&);
 196   gfx::Point3F transform_origin() const { return transform_origin_; }
 197
 198   void SetScrollParent(Layer* parent);
 199
 200   Layer* scroll_parent() { return scroll_parent_; }
 201   const Layer* scroll_parent() const { return scroll_parent_; }
 202
 203   void AddScrollChild(Layer* child);
 204   void RemoveScrollChild(Layer* child);
 205
 206   std::set<Layer*>* scroll_children() { return scroll_children_.get(); }
 207   const std::set<Layer*>* scroll_children() const {
 208     return scroll_children_.get();
 209   }
 210
 211   void SetClipParent(Layer* ancestor);
 212
 213   Layer* clip_parent() { return clip_parent_; }
 214   const Layer* clip_parent() const {
 215     return clip_parent_;
 216   }
 217
 218   void AddClipChild(Layer* child);
 219   void RemoveClipChild(Layer* child);
 220
 221   std::set<Layer*>* clip_children() { return clip_children_.get(); }
 222   const std::set<Layer*>* clip_children() const {
 223     return clip_children_.get();
 224   }
 225
 226   DrawProperties<Layer>& draw_properties() { return draw_properties_; }
 227   const DrawProperties<Layer>& draw_properties() const {
 228     return draw_properties_;
 229   }
 230
 231   // The following are shortcut accessors to get various information from
 232   // draw_properties_
 233   const gfx::Transform& draw_transform() const {
 234     return draw_properties_.target_space_transform;
 235   }
 236   const gfx::Transform& screen_space_transform() const {
 237     return draw_properties_.screen_space_transform;
 238   }
 239   float draw_opacity() const { return draw_properties_.opacity; }
 240   bool draw_opacity_is_animating() const {
 241     return draw_properties_.opacity_is_animating;
 242   }
 243   bool draw_transform_is_animating() const {
 244     return draw_properties_.target_space_transform_is_animating;
 245   }
 246   bool screen_space_transform_is_animating() const {
 247     return draw_properties_.screen_space_transform_is_animating;
 248   }
 249   bool screen_space_opacity_is_animating() const {
 250     return draw_properties_.screen_space_opacity_is_animating;
 251   }
 252   bool is_clipped() const { return draw_properties_.is_clipped; }
 253   gfx::Rect clip_rect() const { return draw_properties_.clip_rect; }
 254   gfx::Rect drawable_content_rect() const {
 255     return draw_properties_.drawable_content_rect;
 256   }
 257   gfx::Rect visible_layer_rect() const {
 258     return draw_properties_.visible_layer_rect;
 259   }
 260   Layer* render_target() {
 261     DCHECK(!draw_properties_.render_target ||
 262            draw_properties_.render_target->render_surface());
 263     return draw_properties_.render_target;
 264   }
 265   const Layer* render_target() const {
 266     DCHECK(!draw_properties_.render_target ||
 267            draw_properties_.render_target->render_surface());
 268     return draw_properties_.render_target;
 269   }
 270   size_t num_unclipped_descendants() const {
 271     return draw_properties_.num_unclipped_descendants;
 272   }
 273
 274   RenderSurface* render_surface() const { return render_surface_.get(); }
 275   void SetScrollOffset(const gfx::ScrollOffset& scroll_offset);
 276   void SetScrollCompensationAdjustment(
 277       const gfx::Vector2dF& scroll_compensation_adjustment);
 278   gfx::Vector2dF ScrollCompensationAdjustment() const;
 279
 280   gfx::ScrollOffset scroll_offset() const { return scroll_offset_; }
 281   void SetScrollOffsetFromImplSide(const gfx::ScrollOffset& scroll_offset);
 282
 283   void SetScrollClipLayerId(int clip_layer_id);
 284   bool scrollable() const { return scroll_clip_layer_id_ != INVALID_ID; }
 285
 286   void SetUserScrollable(bool horizontal, bool vertical);
 287   bool user_scrollable_horizontal() const {
 288     return user_scrollable_horizontal_;
 289   }
 290   bool user_scrollable_vertical() const { return user_scrollable_vertical_; }
 291
 292   void SetShouldScrollOnMainThread(bool should_scroll_on_main_thread);
 293   bool should_scroll_on_main_thread() const {
 294     return should_scroll_on_main_thread_;
 295   }
 296
 297   void SetHaveWheelEventHandlers(bool have_wheel_event_handlers);
 298   bool have_wheel_event_handlers() const { return have_wheel_event_handlers_; }
 299
 300   void SetHaveScrollEventHandlers(bool have_scroll_event_handlers);
 301   bool have_scroll_event_handlers() const {
 302     return have_scroll_event_handlers_;
 303   }
 304
 305   void SetNonFastScrollableRegion(const Region& non_fast_scrollable_region);
 306   const Region& non_fast_scrollable_region() const {
 307     return non_fast_scrollable_region_;
 308   }
 309
 310   void SetTouchEventHandlerRegion(const Region& touch_event_handler_region);
 311   const Region& touch_event_handler_region() const {
 312     return touch_event_handler_region_;
 313   }
 314
 315   void SetScrollBlocksOn(ScrollBlocksOn scroll_blocks_on);
 316   ScrollBlocksOn scroll_blocks_on() const { return scroll_blocks_on_; }
 317
 318   void set_did_scroll_callback(const base::Closure& callback) {
 319     did_scroll_callback_ = callback;
 320   }
 321
 322   void SetDrawCheckerboardForMissingTiles(bool checkerboard);
 323   bool draw_checkerboard_for_missing_tiles() const {
 324     return draw_checkerboard_for_missing_tiles_;
 325   }
 326
 327   void SetForceRenderSurface(bool force_render_surface);
 328   bool force_render_surface() const { return force_render_surface_; }
 329
 330   gfx::Vector2dF ScrollDelta() const { return gfx::Vector2dF(); }
 331   gfx::ScrollOffset CurrentScrollOffset() const { return scroll_offset_; }
 332
 333   void SetDoubleSided(bool double_sided);
 334   bool double_sided() const { return double_sided_; }
 335
 336   void SetShouldFlattenTransform(bool flatten);
 337   bool should_flatten_transform() const { return should_flatten_transform_; }
 338
 339   bool Is3dSorted() const { return sorting_context_id_ != 0; }
 340
 341   void set_use_parent_backface_visibility(bool use) {
 342     use_parent_backface_visibility_ = use;
 343   }
 344   bool use_parent_backface_visibility() const {
 345     return use_parent_backface_visibility_;
 346   }
 347
 348   virtual void SetLayerTreeHost(LayerTreeHost* host);
 349
 350   virtual bool HasDelegatedContent() const;
 351   bool HasContributingDelegatedRenderPasses() const { return false; }
 352
 353   void SetIsDrawable(bool is_drawable);
 354
 355   void SetHideLayerAndSubtree(bool hide);
 356   bool hide_layer_and_subtree() const { return hide_layer_and_subtree_; }
 357
 358   void SetReplicaLayer(Layer* layer);
 359   Layer* replica_layer() { return replica_layer_.get(); }
 360   const Layer* replica_layer() const { return replica_layer_.get(); }
 361
 362   bool has_mask() const { return !!mask_layer_.get(); }
 363   bool has_replica() const { return !!replica_layer_.get(); }
 364   bool replica_has_mask() const {
 365     return replica_layer_.get() &&
 366            (mask_layer_.get() || replica_layer_->mask_layer_.get());
 367   }
 368
 369   int NumDescendantsThatDrawContent() const;
 370
 371   // This is only virtual for tests.
 372   // TODO(awoloszyn): Remove this once we no longer need it for tests
 373   virtual bool DrawsContent() const;
 374
 375   // This methods typically need to be overwritten by derived classes.
 376   virtual void SavePaintProperties();
 377   // Returns true iff anything was updated that needs to be committed.
 378   virtual bool Update();
 379   virtual bool NeedMoreUpdates();
 380   virtual void SetIsMask(bool is_mask) {}
 381   virtual void ReduceMemoryUsage() {}
 382   virtual void OnOutputSurfaceCreated() {}
 383   virtual bool IsSuitableForGpuRasterization() const;
 384
 385   virtual scoped_refptr<base::trace_event::ConvertableToTraceFormat>
 386   TakeDebugInfo();
 387
 388   void SetLayerClient(LayerClient* client) { client_ = client; }
 389
 390   virtual void PushPropertiesTo(LayerImpl* layer);
 391
 392   void CreateRenderSurface();
 393   void ClearRenderSurface();
 394
 395   void ClearRenderSurfaceLayerList();
 396
 397   LayerTreeHost* layer_tree_host() { return layer_tree_host_; }
 398   const LayerTreeHost* layer_tree_host() const { return layer_tree_host_; }
 399
 400   // Set the priority of all desired textures in this layer.
 401   virtual void SetTexturePriorities(const PriorityCalculator& priority_calc) {}
 402
 403   bool AddAnimation(scoped_ptr<Animation> animation);
 404   void PauseAnimation(int animation_id, double time_offset);
 405   void RemoveAnimation(int animation_id);
 406   void RemoveAnimation(int animation_id, Animation::TargetProperty property);
 407
 408   LayerAnimationController* layer_animation_controller() {
 409     return layer_animation_controller_.get();
 410   }
 411   void SetLayerAnimationControllerForTest(
 412       scoped_refptr<LayerAnimationController> controller);
 413
 414   void set_layer_animation_delegate(AnimationDelegate* delegate) {
 415     DCHECK(layer_animation_controller_);
 416     layer_animation_controller_->set_layer_animation_delegate(delegate);
 417   }
 418
 419   bool HasActiveAnimation() const;
 420   void RegisterForAnimations(AnimationRegistrar* registrar);
 421
 422   void AddLayerAnimationEventObserver(
 423       LayerAnimationEventObserver* animation_observer);
 424   void RemoveLayerAnimationEventObserver(
 425       LayerAnimationEventObserver* animation_observer);
 426
 427   virtual ScrollbarLayerInterface* ToScrollbarLayer();
 428
 429   virtual skia::RefPtr<SkPicture> GetPicture() const;
 430
 431   // Constructs a LayerImpl of the correct runtime type for this Layer type.
 432   virtual scoped_ptr<LayerImpl> CreateLayerImpl(LayerTreeImpl* tree_impl);
 433
 434   bool NeedsDisplayForTesting() const { return !update_rect_.IsEmpty(); }
 435   void ResetNeedsDisplayForTesting() { update_rect_ = gfx::Rect(); }
 436
 437   RenderingStatsInstrumentation* rendering_stats_instrumentation() const;
 438
 439   const PaintProperties& paint_properties() const {
 440     return paint_properties_;
 441   }
 442
 443   // The scale at which contents should be rastered, to match the scale at
 444   // which they will drawn to the screen. This scale is a component of the
 445   // contents scale but does not include page/device scale factors.
 446   // TODO(danakj): This goes away when TiledLayer goes away.
 447   void set_raster_scale(float scale) { raster_scale_ = scale; }
 448   float raster_scale() const { return raster_scale_; }
 449   bool raster_scale_is_unknown() const { return raster_scale_ == 0.f; }
 450
 451   void SetNeedsPushProperties();
 452   bool needs_push_properties() const { return needs_push_properties_; }
 453   bool descendant_needs_push_properties() const {
 454     return num_dependents_need_push_properties_ > 0;
 455   }
 456   void reset_needs_push_properties_for_testing() {
 457     needs_push_properties_ = false;
 458   }
 459
 460   virtual void RunMicroBenchmark(MicroBenchmark* benchmark);
 461
 462   void Set3dSortingContextId(int id);
 463   int sorting_context_id() const { return sorting_context_id_; }
 464
 465   void set_property_tree_sequence_number(int sequence_number) {
 466     property_tree_sequence_number_ = sequence_number;
 467   }
 468
 469   void SetTransformTreeIndex(int index);
 470   int transform_tree_index() const;
 471
 472   void SetClipTreeIndex(int index);
 473   int clip_tree_index() const;
 474
 475   void SetOpacityTreeIndex(int index);
 476   int opacity_tree_index() const;
 477
 478   void set_offset_to_transform_parent(gfx::Vector2dF offset) {
 479     if (offset_to_transform_parent_ == offset)
 480       return;
 481     offset_to_transform_parent_ = offset;
 482     SetNeedsPushProperties();
 483   }
 484   gfx::Vector2dF offset_to_transform_parent() const {
 485     return offset_to_transform_parent_;
 486   }
 487
 488   // TODO(vollick): Once we transition to transform and clip trees, rename these
 489   // functions and related values.  The "from property trees" functions below
 490   // use the transform and clip trees.  Eventually, we will use these functions
 491   // to compute the official values, but these functions are retained for
 492   // testing purposes until we've migrated.
 493
 494   const gfx::Rect& visible_rect_from_property_trees() const {
 495     return visible_rect_from_property_trees_;
 496   }
 497   void set_visible_rect_from_property_trees(const gfx::Rect& rect) {
 498     // No push properties here, as this acts like a draw property.
 499     visible_rect_from_property_trees_ = rect;
 500   }
 501
 502   void set_should_flatten_transform_from_property_tree(bool should_flatten) {
 503     if (should_flatten_transform_from_property_tree_ == should_flatten)
 504       return;
 505     should_flatten_transform_from_property_tree_ = should_flatten;
 506     SetNeedsPushProperties();
 507   }
 508   bool should_flatten_transform_from_property_tree() const {
 509     return should_flatten_transform_from_property_tree_;
 510   }
 511
 512   // TODO(vollick): These values are temporary and will be removed as soon as
 513   // render surface determinations are moved out of CDP. They only exist because
 514   // certain logic depends on whether or not a layer would render to a separate
 515   // surface, but CDP destroys surfaces and targets it doesn't need, so without
 516   // this boolean, this is impossible to determine after the fact without
 517   // wastefully recomputing it. This is public for the time being so that it can
 518   // be accessed from CDP.
 519   bool has_render_surface() const {
 520     return has_render_surface_;
 521   }
 522
 523   // Sets new frame timing requests for this layer.
 524   void SetFrameTimingRequests(const std::vector<FrameTimingRequest>& requests);
 525
 526   // Accessor for unit tests
 527   const std::vector<FrameTimingRequest>& FrameTimingRequests() const {
 528     return frame_timing_requests_;
 529   }
 530
 531   void DidBeginTracing();
 532   void set_num_layer_or_descandant_with_copy_request(
 533       int num_layer_or_descendants_with_copy_request) {
 534     num_layer_or_descendants_with_copy_request_ =
 535         num_layer_or_descendants_with_copy_request;
 536   }
 537
 538   void set_num_layer_or_descandant_with_input_handler(
 539       int num_layer_or_descendants_with_input_handler) {
 540     num_layer_or_descendants_with_input_handler_ =
 541         num_layer_or_descendants_with_input_handler;
 542   }
 543
 544   int num_layer_or_descendants_with_input_handler() {
 545     return num_layer_or_descendants_with_input_handler_;
 546   }
 547
 548   void set_num_children_with_scroll_parent(
 549       int num_children_with_scroll_parent) {
 550     num_children_with_scroll_parent_ = num_children_with_scroll_parent;
 551   }
 552
 553   int num_children_with_scroll_parent() {
 554     return num_children_with_scroll_parent_;
 555   }
 556
 557   void set_visited(bool visited);
 558   bool visited();
 559   void set_layer_or_descendant_is_drawn(bool layer_or_descendant_is_drawn);
 560   bool layer_or_descendant_is_drawn();
 561   void set_sorted_for_recursion(bool sorted_for_recursion);
 562   bool sorted_for_recursion();
 563
 564  protected:
 565   friend class LayerImpl;
 566   friend class TreeSynchronizer;
 567   ~Layer() override;
 568
 569   explicit Layer(const LayerSettings& settings);
 570
 571   // These SetNeeds functions are in order of severity of update:
 572   //
 573   // Called when this layer has been modified in some way, but isn't sure
 574   // that it needs a commit yet.  It needs CalcDrawProperties and UpdateLayers
 575   // before it knows whether or not a commit is required.
 576   void SetNeedsUpdate();
 577   // Called when a property has been modified in a way that the layer
 578   // knows immediately that a commit is required.  This implies SetNeedsUpdate
 579   // as well as SetNeedsPushProperties to push that property.
 580   void SetNeedsCommit();
 581   // This is identical to SetNeedsCommit, but the former requests a rebuild of
 582   // the property trees.
 583   void SetNeedsCommitNoRebuild();
 584   // Called when there's been a change in layer structure.  Implies both
 585   // SetNeedsUpdate and SetNeedsCommit, but not SetNeedsPushProperties.
 586   void SetNeedsFullTreeSync();
 587
 588   // Called when the next commit should wait until the pending tree is activated
 589   // before finishing the commit and unblocking the main thread. Used to ensure
 590   // unused resources on the impl thread are returned before commit completes.
 591   void SetNextCommitWaitsForActivation();
 592
 593   // Will recalculate whether the layer draws content and set draws_content_
 594   // appropriately.
 595   void UpdateDrawsContent(bool has_drawable_content);
 596   virtual bool HasDrawableContent() const;
 597
 598   // Called when the layer's number of drawable descendants changes.
 599   void AddDrawableDescendants(int num);
 600
 601   void AddDependentNeedsPushProperties();
 602   void RemoveDependentNeedsPushProperties();
 603   bool parent_should_know_need_push_properties() const {
 604     return needs_push_properties() || descendant_needs_push_properties();
 605   }
 606
 607   bool IsPropertyChangeAllowed() const;
 608
 609   void reset_raster_scale_to_unknown() { raster_scale_ = 0.f; }
 610
 611   // This flag is set when the layer needs to push properties to the impl
 612   // side.
 613   bool needs_push_properties_;
 614
 615   // The number of direct children or dependent layers that need to be recursed
 616   // to in order for them or a descendent of them to push properties to the impl
 617   // side.
 618   int num_dependents_need_push_properties_;
 619
 620   // Tracks whether this layer may have changed stacking order with its
 621   // siblings.
 622   bool stacking_order_changed_;
 623
 624   // The update rect is the region of the compositor resource that was
 625   // actually updated by the compositor. For layers that may do updating
 626   // outside the compositor's control (i.e. plugin layers), this information
 627   // is not available and the update rect will remain empty.
 628   // Note this rect is in layer space (not content space).
 629   gfx::Rect update_rect_;
 630
 631   scoped_refptr<Layer> mask_layer_;
 632
 633   int layer_id_;
 634
 635   // When true, the layer is about to perform an update. Any commit requests
 636   // will be handled implicitly after the update completes.
 637   bool ignore_set_needs_commit_;
 638
 639   // Layers that share a sorting context id will be sorted together in 3d
 640   // space.  0 is a special value that means this layer will not be sorted and
 641   // will be drawn in paint order.
 642   int sorting_context_id_;
 643
 644  private:
 645   friend class base::RefCounted<Layer>;
 646   friend class LayerTreeHostCommon;
 647   void SetParent(Layer* layer);
 648   bool DescendantIsFixedToContainerLayer() const;
 649
 650   // This should only be called during BeginMainFrame since it does not
 651   // trigger a Commit.
 652   void SetHasRenderSurface(bool has_render_surface);
 653
 654   // This should only be called from RemoveFromParent().
 655   void RemoveChildOrDependent(Layer* child);
 656
 657   // LayerAnimationValueProvider implementation.
 658   gfx::ScrollOffset ScrollOffsetForAnimation() const override;
 659
 660   // LayerAnimationValueObserver implementation.
 661   void OnFilterAnimated(const FilterOperations& filters) override;
 662   void OnOpacityAnimated(float opacity) override;
 663   void OnTransformAnimated(const gfx::Transform& transform) override;
 664   void OnScrollOffsetAnimated(const gfx::ScrollOffset& scroll_offset) override;
 665   void OnAnimationWaitingForDeletion() override;
 666   bool IsActive() const override;
 667
 668   // If this layer has a scroll parent, it removes |this| from its list of
 669   // scroll children.
 670   void RemoveFromScrollTree();
 671
 672   // If this layer has a clip parent, it removes |this| from its list of clip
 673   // children.
 674   void RemoveFromClipTree();
 675
 676   // When we detach or attach layer to new LayerTreeHost, all property trees'
 677   // indices becomes invalid.
 678   void InvalidatePropertyTreesIndices();
 679
 680   void UpdateNumCopyRequestsForSubtree(bool add);
 681   void UpdateNumInputHandlersForSubtree(bool add);
 682
 683   LayerList children_;
 684   Layer* parent_;
 685
 686   // Layer instances have a weak pointer to their LayerTreeHost.
 687   // This pointer value is nil when a Layer is not in a tree and is
 688   // updated via SetLayerTreeHost() if a layer moves between trees.
 689   LayerTreeHost* layer_tree_host_;
 690
 691   scoped_refptr<LayerAnimationController> layer_animation_controller_;
 692
 693   // Layer properties.
 694   gfx::Size bounds_;
 695
 696   gfx::ScrollOffset scroll_offset_;
 697   gfx::Vector2dF scroll_compensation_adjustment_;
 698   // This variable indicates which ancestor layer (if any) whose size,
 699   // transformed relative to this layer, defines the maximum scroll offset for
 700   // this layer.
 701   int scroll_clip_layer_id_;
 702   int num_descendants_that_draw_content_;
 703   int transform_tree_index_;
 704   int opacity_tree_index_;
 705   int clip_tree_index_;
 706   int property_tree_sequence_number_;
 707   int num_layer_or_descendants_with_copy_request_;
 708   int num_layer_or_descendants_with_input_handler_;
 709   int num_children_with_scroll_parent_;
 710   gfx::Vector2dF offset_to_transform_parent_;
 711   bool should_flatten_transform_from_property_tree_ : 1;
 712   bool should_scroll_on_main_thread_ : 1;
 713   bool have_wheel_event_handlers_ : 1;
 714   bool have_scroll_event_handlers_ : 1;
 715   bool user_scrollable_horizontal_ : 1;
 716   bool user_scrollable_vertical_ : 1;
 717   bool is_root_for_isolated_group_ : 1;
 718   bool is_container_for_fixed_position_layers_ : 1;
 719   bool is_drawable_ : 1;
 720   bool draws_content_ : 1;
 721   bool hide_layer_and_subtree_ : 1;
 722   bool masks_to_bounds_ : 1;
 723   bool contents_opaque_ : 1;
 724   bool double_sided_ : 1;
 725   bool should_flatten_transform_ : 1;
 726   bool use_parent_backface_visibility_ : 1;
 727   bool draw_checkerboard_for_missing_tiles_ : 1;
 728   bool force_render_surface_ : 1;
 729   bool transform_is_invertible_ : 1;
 730   bool has_render_surface_ : 1;
 731   ScrollBlocksOn scroll_blocks_on_ : 3;
 732   Region non_fast_scrollable_region_;
 733   Region touch_event_handler_region_;
 734   gfx::PointF position_;
 735   SkColor background_color_;
 736   float opacity_;
 737   SkXfermode::Mode blend_mode_;
 738   FilterOperations filters_;
 739   FilterOperations background_filters_;
 740   LayerPositionConstraint position_constraint_;
 741   Layer* scroll_parent_;
 742   scoped_ptr<std::set<Layer*>> scroll_children_;
 743
 744   // The following three variables are tracker variables. They are bools
 745   // wrapped inside an integer variable. If true, their value equals the
 746   // LayerTreeHost's meta_information_sequence_number. This wrapping of bools
 747   // inside ints is done to avoid a layer tree treewalk to reset their values.
 748   int layer_or_descendant_is_drawn_tracker_;
 749   int sorted_for_recursion_tracker_;
 750   int visited_tracker_;
 751
 752   Layer* clip_parent_;
 753   scoped_ptr<std::set<Layer*>> clip_children_;
 754
 755   gfx::Transform transform_;
 756   gfx::Point3F transform_origin_;
 757
 758   // Replica layer used for reflections.
 759   scoped_refptr<Layer> replica_layer_;
 760
 761   // Transient properties.
 762   float raster_scale_;
 763
 764   LayerClient* client_;
 765
 766   ScopedPtrVector<CopyOutputRequest> copy_requests_;
 767
 768   base::Closure did_scroll_callback_;
 769
 770   DrawProperties<Layer> draw_properties_;
 771
 772   PaintProperties paint_properties_;
 773   // TODO(awoloszyn): This is redundant with has_render_surface_,
 774   // and should get removed once it is no longer needed on main thread.
 775   scoped_ptr<RenderSurface> render_surface_;
 776
 777   gfx::Rect visible_rect_from_property_trees_;
 778
 779   std::vector<FrameTimingRequest> frame_timing_requests_;
 780   bool frame_timing_requests_dirty_;
 781
 782   DISALLOW_COPY_AND_ASSIGN(Layer);
 783 };
 784
 785 }  // namespace cc
 786
 787 #endif  // CC_LAYERS_LAYER_H_