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   virtual bool OpacityCanAnimateOnImplThread() const;
 139
 140   void SetBlendMode(SkXfermode::Mode blend_mode);
 141   SkXfermode::Mode blend_mode() const { return blend_mode_; }
 142
 143   bool uses_default_blend_mode() const {
 144     return blend_mode_ == SkXfermode::kSrcOver_Mode;
 145   }
 146
 147   // A layer is root for an isolated group when it and all its descendants are
 148   // drawn over a black and fully transparent background, creating an isolated
 149   // group. It should be used along with SetBlendMode(), in order to restrict
 150   // layers within the group to blend with layers outside this group.
 151   void SetIsRootForIsolatedGroup(bool root);
 152   bool is_root_for_isolated_group() const {
 153     return is_root_for_isolated_group_;
 154   }
 155
 156   void SetFilters(const FilterOperations& filters);
 157   const FilterOperations& filters() const { return filters_; }
 158   bool FilterIsAnimating() const;
 159
 160   // Background filters are filters applied to what is behind this layer, when
 161   // they are viewed through non-opaque regions in this layer. They are used
 162   // through the WebLayer interface, and are not exposed to HTML.
 163   void SetBackgroundFilters(const FilterOperations& filters);
 164   const FilterOperations& background_filters() const {
 165     return background_filters_;
 166   }
 167
 168   virtual void SetContentsOpaque(bool opaque);
 169   bool contents_opaque() const { return contents_opaque_; }
 170
 171   void SetPosition(const gfx::PointF& position);
 172   gfx::PointF position() const { return position_; }
 173
 174   // A layer that is a container for fixed position layers cannot be both
 175   // scrollable and have a non-identity transform.
 176   void SetIsContainerForFixedPositionLayers(bool container);
 177   bool IsContainerForFixedPositionLayers() const;
 178
 179   gfx::Vector2dF FixedContainerSizeDelta() const {
 180     return gfx::Vector2dF();
 181   }
 182
 183   void SetPositionConstraint(const LayerPositionConstraint& constraint);
 184   const LayerPositionConstraint& position_constraint() const {
 185     return position_constraint_;
 186   }
 187
 188   void SetTransform(const gfx::Transform& transform);
 189   const gfx::Transform& transform() const { return transform_; }
 190   bool TransformIsAnimating() const;
 191   bool AnimationsPreserveAxisAlignment() const;
 192   bool transform_is_invertible() const { return transform_is_invertible_; }
 193
 194   void SetTransformOrigin(const gfx::Point3F&);
 195   gfx::Point3F transform_origin() const { return transform_origin_; }
 196
 197   void SetScrollParent(Layer* parent);
 198
 199   Layer* scroll_parent() { return scroll_parent_; }
 200   const Layer* scroll_parent() const { return scroll_parent_; }
 201
 202   void AddScrollChild(Layer* child);
 203   void RemoveScrollChild(Layer* child);
 204
 205   std::set<Layer*>* scroll_children() { return scroll_children_.get(); }
 206   const std::set<Layer*>* scroll_children() const {
 207     return scroll_children_.get();
 208   }
 209
 210   void SetClipParent(Layer* ancestor);
 211
 212   Layer* clip_parent() { return clip_parent_; }
 213   const Layer* clip_parent() const {
 214     return clip_parent_;
 215   }
 216
 217   void AddClipChild(Layer* child);
 218   void RemoveClipChild(Layer* child);
 219
 220   std::set<Layer*>* clip_children() { return clip_children_.get(); }
 221   const std::set<Layer*>* clip_children() const {
 222     return clip_children_.get();
 223   }
 224
 225   DrawProperties<Layer>& draw_properties() { return draw_properties_; }
 226   const DrawProperties<Layer>& draw_properties() const {
 227     return draw_properties_;
 228   }
 229
 230   // The following are shortcut accessors to get various information from
 231   // draw_properties_
 232   const gfx::Transform& draw_transform() const {
 233     return draw_properties_.target_space_transform;
 234   }
 235   const gfx::Transform& screen_space_transform() const {
 236     return draw_properties_.screen_space_transform;
 237   }
 238   float draw_opacity() const { return draw_properties_.opacity; }
 239   bool draw_opacity_is_animating() const {
 240     return draw_properties_.opacity_is_animating;
 241   }
 242   bool draw_transform_is_animating() const {
 243     return draw_properties_.target_space_transform_is_animating;
 244   }
 245   bool screen_space_transform_is_animating() const {
 246     return draw_properties_.screen_space_transform_is_animating;
 247   }
 248   bool screen_space_opacity_is_animating() const {
 249     return draw_properties_.screen_space_opacity_is_animating;
 250   }
 251   bool is_clipped() const { return draw_properties_.is_clipped; }
 252   gfx::Rect clip_rect() const { return draw_properties_.clip_rect; }
 253   gfx::Rect drawable_content_rect() const {
 254     return draw_properties_.drawable_content_rect;
 255   }
 256   gfx::Rect visible_layer_rect() const {
 257     return draw_properties_.visible_layer_rect;
 258   }
 259   Layer* render_target() {
 260     DCHECK(!draw_properties_.render_target ||
 261            draw_properties_.render_target->render_surface());
 262     return draw_properties_.render_target;
 263   }
 264   const Layer* render_target() const {
 265     DCHECK(!draw_properties_.render_target ||
 266            draw_properties_.render_target->render_surface());
 267     return draw_properties_.render_target;
 268   }
 269   size_t num_unclipped_descendants() const {
 270     return draw_properties_.num_unclipped_descendants;
 271   }
 272
 273   RenderSurface* render_surface() const { return render_surface_.get(); }
 274   void SetScrollOffset(const gfx::ScrollOffset& scroll_offset);
 275   void SetScrollCompensationAdjustment(
 276       const gfx::Vector2dF& scroll_compensation_adjustment);
 277   gfx::Vector2dF ScrollCompensationAdjustment() const;
 278
 279   gfx::ScrollOffset scroll_offset() const { return scroll_offset_; }
 280   void SetScrollOffsetFromImplSide(const gfx::ScrollOffset& scroll_offset);
 281
 282   void SetScrollClipLayerId(int clip_layer_id);
 283   bool scrollable() const { return scroll_clip_layer_id_ != INVALID_ID; }
 284
 285   void SetUserScrollable(bool horizontal, bool vertical);
 286   bool user_scrollable_horizontal() const {
 287     return user_scrollable_horizontal_;
 288   }
 289   bool user_scrollable_vertical() const { return user_scrollable_vertical_; }
 290
 291   void SetShouldScrollOnMainThread(bool should_scroll_on_main_thread);
 292   bool should_scroll_on_main_thread() const {
 293     return should_scroll_on_main_thread_;
 294   }
 295
 296   void SetHaveWheelEventHandlers(bool have_wheel_event_handlers);
 297   bool have_wheel_event_handlers() const { return have_wheel_event_handlers_; }
 298
 299   void SetHaveScrollEventHandlers(bool have_scroll_event_handlers);
 300   bool have_scroll_event_handlers() const {
 301     return have_scroll_event_handlers_;
 302   }
 303
 304   void SetNonFastScrollableRegion(const Region& non_fast_scrollable_region);
 305   const Region& non_fast_scrollable_region() const {
 306     return non_fast_scrollable_region_;
 307   }
 308
 309   void SetTouchEventHandlerRegion(const Region& touch_event_handler_region);
 310   const Region& touch_event_handler_region() const {
 311     return touch_event_handler_region_;
 312   }
 313
 314   void SetScrollBlocksOn(ScrollBlocksOn scroll_blocks_on);
 315   ScrollBlocksOn scroll_blocks_on() const { return scroll_blocks_on_; }
 316
 317   void set_did_scroll_callback(const base::Closure& callback) {
 318     did_scroll_callback_ = callback;
 319   }
 320
 321   void SetDrawCheckerboardForMissingTiles(bool checkerboard);
 322   bool draw_checkerboard_for_missing_tiles() const {
 323     return draw_checkerboard_for_missing_tiles_;
 324   }
 325
 326   void SetForceRenderSurface(bool force_render_surface);
 327   bool force_render_surface() const { return force_render_surface_; }
 328
 329   gfx::Vector2dF ScrollDelta() const { return gfx::Vector2dF(); }
 330   gfx::ScrollOffset CurrentScrollOffset() const { return scroll_offset_; }
 331
 332   void SetDoubleSided(bool double_sided);
 333   bool double_sided() const { return double_sided_; }
 334
 335   void SetShouldFlattenTransform(bool flatten);
 336   bool should_flatten_transform() const { return should_flatten_transform_; }
 337
 338   bool Is3dSorted() const { return sorting_context_id_ != 0; }
 339
 340   void set_use_parent_backface_visibility(bool use) {
 341     use_parent_backface_visibility_ = use;
 342   }
 343   bool use_parent_backface_visibility() const {
 344     return use_parent_backface_visibility_;
 345   }
 346
 347   virtual void SetLayerTreeHost(LayerTreeHost* host);
 348
 349   virtual bool HasDelegatedContent() const;
 350   bool HasContributingDelegatedRenderPasses() const { return false; }
 351
 352   void SetIsDrawable(bool is_drawable);
 353
 354   void SetHideLayerAndSubtree(bool hide);
 355   bool hide_layer_and_subtree() const { return hide_layer_and_subtree_; }
 356
 357   void SetReplicaLayer(Layer* layer);
 358   Layer* replica_layer() { return replica_layer_.get(); }
 359   const Layer* replica_layer() const { return replica_layer_.get(); }
 360
 361   bool has_mask() const { return !!mask_layer_.get(); }
 362   bool has_replica() const { return !!replica_layer_.get(); }
 363   bool replica_has_mask() const {
 364     return replica_layer_.get() &&
 365            (mask_layer_.get() || replica_layer_->mask_layer_.get());
 366   }
 367
 368   int NumDescendantsThatDrawContent() const;
 369
 370   // This is only virtual for tests.
 371   // TODO(awoloszyn): Remove this once we no longer need it for tests
 372   virtual bool DrawsContent() const;
 373
 374   // This methods typically need to be overwritten by derived classes.
 375   virtual void SavePaintProperties();
 376   // Returns true iff anything was updated that needs to be committed.
 377   virtual bool Update();
 378   virtual bool NeedMoreUpdates();
 379   virtual void SetIsMask(bool is_mask) {}
 380   virtual void ReduceMemoryUsage() {}
 381   virtual void OnOutputSurfaceCreated() {}
 382   virtual bool IsSuitableForGpuRasterization() const;
 383
 384   virtual scoped_refptr<base::trace_event::ConvertableToTraceFormat>
 385   TakeDebugInfo();
 386
 387   void SetLayerClient(LayerClient* client) { client_ = client; }
 388
 389   virtual void PushPropertiesTo(LayerImpl* layer);
 390
 391   void CreateRenderSurface();
 392   void ClearRenderSurface();
 393
 394   void ClearRenderSurfaceLayerList();
 395
 396   LayerTreeHost* layer_tree_host() { return layer_tree_host_; }
 397   const LayerTreeHost* layer_tree_host() const { return layer_tree_host_; }
 398
 399   bool AddAnimation(scoped_ptr<Animation> animation);
 400   void PauseAnimation(int animation_id, double time_offset);
 401   void RemoveAnimation(int animation_id);
 402   void RemoveAnimation(int animation_id, Animation::TargetProperty property);
 403
 404   LayerAnimationController* layer_animation_controller() {
 405     return layer_animation_controller_.get();
 406   }
 407   void SetLayerAnimationControllerForTest(
 408       scoped_refptr<LayerAnimationController> controller);
 409
 410   void set_layer_animation_delegate(AnimationDelegate* delegate) {
 411     DCHECK(layer_animation_controller_);
 412     layer_animation_controller_->set_layer_animation_delegate(delegate);
 413   }
 414
 415   bool HasActiveAnimation() const;
 416   void RegisterForAnimations(AnimationRegistrar* registrar);
 417
 418   void AddLayerAnimationEventObserver(
 419       LayerAnimationEventObserver* animation_observer);
 420   void RemoveLayerAnimationEventObserver(
 421       LayerAnimationEventObserver* animation_observer);
 422
 423   virtual ScrollbarLayerInterface* ToScrollbarLayer();
 424
 425   virtual skia::RefPtr<SkPicture> GetPicture() const;
 426
 427   // Constructs a LayerImpl of the correct runtime type for this Layer type.
 428   virtual scoped_ptr<LayerImpl> CreateLayerImpl(LayerTreeImpl* tree_impl);
 429
 430   bool NeedsDisplayForTesting() const { return !update_rect_.IsEmpty(); }
 431   void ResetNeedsDisplayForTesting() { update_rect_ = gfx::Rect(); }
 432
 433   RenderingStatsInstrumentation* rendering_stats_instrumentation() const;
 434
 435   const PaintProperties& paint_properties() const {
 436     return paint_properties_;
 437   }
 438
 439   // The scale at which contents should be rastered, to match the scale at
 440   // which they will drawn to the screen. This scale is a component of the
 441   // contents scale but does not include page/device scale factors.
 442   // TODO(danakj): This goes away when TiledLayer goes away.
 443   void set_raster_scale(float scale) { raster_scale_ = scale; }
 444   float raster_scale() const { return raster_scale_; }
 445   bool raster_scale_is_unknown() const { return raster_scale_ == 0.f; }
 446
 447   void SetNeedsPushProperties();
 448   bool needs_push_properties() const { return needs_push_properties_; }
 449   bool descendant_needs_push_properties() const {
 450     return num_dependents_need_push_properties_ > 0;
 451   }
 452   void reset_needs_push_properties_for_testing() {
 453     needs_push_properties_ = false;
 454   }
 455
 456   virtual void RunMicroBenchmark(MicroBenchmark* benchmark);
 457
 458   void Set3dSortingContextId(int id);
 459   int sorting_context_id() const { return sorting_context_id_; }
 460
 461   void set_property_tree_sequence_number(int sequence_number) {
 462     property_tree_sequence_number_ = sequence_number;
 463   }
 464
 465   void SetTransformTreeIndex(int index);
 466   int transform_tree_index() const;
 467
 468   void SetClipTreeIndex(int index);
 469   int clip_tree_index() const;
 470
 471   void SetOpacityTreeIndex(int index);
 472   int opacity_tree_index() const;
 473
 474   void set_offset_to_transform_parent(gfx::Vector2dF offset) {
 475     if (offset_to_transform_parent_ == offset)
 476       return;
 477     offset_to_transform_parent_ = offset;
 478     SetNeedsPushProperties();
 479   }
 480   gfx::Vector2dF offset_to_transform_parent() const {
 481     return offset_to_transform_parent_;
 482   }
 483
 484   // TODO(vollick): Once we transition to transform and clip trees, rename these
 485   // functions and related values.  The "from property trees" functions below
 486   // use the transform and clip trees.  Eventually, we will use these functions
 487   // to compute the official values, but these functions are retained for
 488   // testing purposes until we've migrated.
 489
 490   const gfx::Rect& visible_rect_from_property_trees() const {
 491     return visible_rect_from_property_trees_;
 492   }
 493   void set_visible_rect_from_property_trees(const gfx::Rect& rect) {
 494     // No push properties here, as this acts like a draw property.
 495     visible_rect_from_property_trees_ = rect;
 496   }
 497
 498   void set_should_flatten_transform_from_property_tree(bool should_flatten) {
 499     if (should_flatten_transform_from_property_tree_ == should_flatten)
 500       return;
 501     should_flatten_transform_from_property_tree_ = should_flatten;
 502     SetNeedsPushProperties();
 503   }
 504   bool should_flatten_transform_from_property_tree() const {
 505     return should_flatten_transform_from_property_tree_;
 506   }
 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   void reset_raster_scale_to_unknown() { raster_scale_ = 0.f; }
 606
 607   // This flag is set when the layer needs to push properties to the impl
 608   // side.
 609   bool needs_push_properties_;
 610
 611   // The number of direct children or dependent layers that need to be recursed
 612   // to in order for them or a descendent of them to push properties to the impl
 613   // side.
 614   int num_dependents_need_push_properties_;
 615
 616   // Tracks whether this layer may have changed stacking order with its
 617   // siblings.
 618   bool stacking_order_changed_;
 619
 620   // The update rect is the region of the compositor resource that was
 621   // actually updated by the compositor. For layers that may do updating
 622   // outside the compositor's control (i.e. plugin layers), this information
 623   // is not available and the update rect will remain empty.
 624   // Note this rect is in layer space (not content space).
 625   gfx::Rect update_rect_;
 626
 627   scoped_refptr<Layer> mask_layer_;
 628
 629   int layer_id_;
 630
 631   // When true, the layer is about to perform an update. Any commit requests
 632   // will be handled implicitly after the update completes.
 633   bool ignore_set_needs_commit_;
 634
 635   // Layers that share a sorting context id will be sorted together in 3d
 636   // space.  0 is a special value that means this layer will not be sorted and
 637   // will be drawn in paint order.
 638   int sorting_context_id_;
 639
 640  private:
 641   friend class base::RefCounted<Layer>;
 642   friend class LayerTreeHostCommon;
 643   void SetParent(Layer* layer);
 644   bool DescendantIsFixedToContainerLayer() const;
 645
 646   // This should only be called during BeginMainFrame since it does not
 647   // trigger a Commit.
 648   void SetHasRenderSurface(bool has_render_surface);
 649
 650   // This should only be called from RemoveFromParent().
 651   void RemoveChildOrDependent(Layer* child);
 652
 653   // LayerAnimationValueProvider implementation.
 654   gfx::ScrollOffset ScrollOffsetForAnimation() const override;
 655
 656   // LayerAnimationValueObserver implementation.
 657   void OnFilterAnimated(const FilterOperations& filters) override;
 658   void OnOpacityAnimated(float opacity) override;
 659   void OnTransformAnimated(const gfx::Transform& transform) override;
 660   void OnScrollOffsetAnimated(const gfx::ScrollOffset& scroll_offset) override;
 661   void OnAnimationWaitingForDeletion() override;
 662   bool IsActive() const override;
 663
 664   // If this layer has a scroll parent, it removes |this| from its list of
 665   // scroll children.
 666   void RemoveFromScrollTree();
 667
 668   // If this layer has a clip parent, it removes |this| from its list of clip
 669   // children.
 670   void RemoveFromClipTree();
 671
 672   // When we detach or attach layer to new LayerTreeHost, all property trees'
 673   // indices becomes invalid.
 674   void InvalidatePropertyTreesIndices();
 675
 676   void UpdateNumCopyRequestsForSubtree(bool add);
 677   void UpdateNumInputHandlersForSubtree(bool add);
 678
 679   LayerList children_;
 680   Layer* parent_;
 681
 682   // Layer instances have a weak pointer to their LayerTreeHost.
 683   // This pointer value is nil when a Layer is not in a tree and is
 684   // updated via SetLayerTreeHost() if a layer moves between trees.
 685   LayerTreeHost* layer_tree_host_;
 686
 687   scoped_refptr<LayerAnimationController> layer_animation_controller_;
 688
 689   // Layer properties.
 690   gfx::Size bounds_;
 691
 692   gfx::ScrollOffset scroll_offset_;
 693   gfx::Vector2dF scroll_compensation_adjustment_;
 694   // This variable indicates which ancestor layer (if any) whose size,
 695   // transformed relative to this layer, defines the maximum scroll offset for
 696   // this layer.
 697   int scroll_clip_layer_id_;
 698   int num_descendants_that_draw_content_;
 699   int transform_tree_index_;
 700   int opacity_tree_index_;
 701   int clip_tree_index_;
 702   int property_tree_sequence_number_;
 703   int num_layer_or_descendants_with_copy_request_;
 704   int num_layer_or_descendants_with_input_handler_;
 705   int num_children_with_scroll_parent_;
 706   gfx::Vector2dF offset_to_transform_parent_;
 707   bool should_flatten_transform_from_property_tree_ : 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 draw_checkerboard_for_missing_tiles_ : 1;
 724   bool force_render_surface_ : 1;
 725   bool transform_is_invertible_ : 1;
 726   bool has_render_surface_ : 1;
 727   ScrollBlocksOn scroll_blocks_on_ : 3;
 728   Region non_fast_scrollable_region_;
 729   Region touch_event_handler_region_;
 730   gfx::PointF position_;
 731   SkColor background_color_;
 732   float opacity_;
 733   SkXfermode::Mode blend_mode_;
 734   FilterOperations filters_;
 735   FilterOperations background_filters_;
 736   LayerPositionConstraint position_constraint_;
 737   Layer* scroll_parent_;
 738   scoped_ptr<std::set<Layer*>> scroll_children_;
 739
 740   // The following three variables are tracker variables. They are bools
 741   // wrapped inside an integer variable. If true, their value equals the
 742   // LayerTreeHost's meta_information_sequence_number. This wrapping of bools
 743   // inside ints is done to avoid a layer tree treewalk to reset their values.
 744   int layer_or_descendant_is_drawn_tracker_;
 745   int sorted_for_recursion_tracker_;
 746   int visited_tracker_;
 747
 748   Layer* clip_parent_;
 749   scoped_ptr<std::set<Layer*>> clip_children_;
 750
 751   gfx::Transform transform_;
 752   gfx::Point3F transform_origin_;
 753
 754   // Replica layer used for reflections.
 755   scoped_refptr<Layer> replica_layer_;
 756
 757   // Transient properties.
 758   float raster_scale_;
 759
 760   LayerClient* client_;
 761
 762   ScopedPtrVector<CopyOutputRequest> copy_requests_;
 763
 764   base::Closure did_scroll_callback_;
 765
 766   DrawProperties<Layer> draw_properties_;
 767
 768   PaintProperties paint_properties_;
 769   // TODO(awoloszyn): This is redundant with has_render_surface_,
 770   // and should get removed once it is no longer needed on main thread.
 771   scoped_ptr<RenderSurface> render_surface_;
 772
 773   gfx::Rect visible_rect_from_property_trees_;
 774
 775   std::vector<FrameTimingRequest> frame_timing_requests_;
 776   bool frame_timing_requests_dirty_;
 777
 778   DISALLOW_COPY_AND_ASSIGN(Layer);
 779 };
 780
 781 }  // namespace cc
 782
 783 #endif  // CC_LAYERS_LAYER_H_