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/scroll_blocks_on.h"
  28 #include "cc/output/filter_operations.h"
  29 #include "cc/trees/property_tree.h"
  30 #include "skia/ext/refptr.h"
  31 #include "third_party/skia/include/core/SkColor.h"
  32 #include "third_party/skia/include/core/SkImageFilter.h"
  33 #include "third_party/skia/include/core/SkPicture.h"
  34 #include "third_party/skia/include/core/SkXfermode.h"
  35 #include "ui/gfx/geometry/point3_f.h"
  36 #include "ui/gfx/geometry/rect.h"
  37 #include "ui/gfx/geometry/rect_f.h"
  38 #include "ui/gfx/geometry/scroll_offset.h"
  39 #include "ui/gfx/transform.h"
  40
  41 namespace gfx {
  42 class BoxF;
  43 }
  44
  45 namespace base {
  46 namespace trace_event {
  47 class ConvertableToTraceFormat;
  48 }
  49 }
  50
  51 namespace cc {
  52
  53 class Animation;
  54 class AnimationDelegate;
  55 struct AnimationEvent;
  56 class CopyOutputRequest;
  57 class LayerAnimationEventObserver;
  58 class LayerClient;
  59 class LayerImpl;
  60 class LayerSettings;
  61 class LayerTreeHost;
  62 class LayerTreeHostCommon;
  63 class LayerTreeImpl;
  64 class LayerTreeSettings;
  65 class RenderingStatsInstrumentation;
  66 class ResourceUpdateQueue;
  67 class ScrollbarLayerInterface;
  68 class SimpleEnclosedRegion;
  69 struct AnimationEvent;
  70
  71 // Base class for composited layers. Special layer types are derived from
  72 // this class.
  73 class CC_EXPORT Layer : public base::RefCounted<Layer>,
  74                         public LayerAnimationValueObserver,
  75                         public LayerAnimationValueProvider {
  76  public:
  77   typedef LayerList LayerListType;
  78
  79   enum LayerIdLabels {
  80     INVALID_ID = -1,
  81   };
  82
  83   static scoped_refptr<Layer> Create(const LayerSettings& settings);
  84
  85   int id() const { return layer_id_; }
  86
  87   Layer* RootLayer();
  88   Layer* parent() { return parent_; }
  89   const Layer* parent() const { return parent_; }
  90   void AddChild(scoped_refptr<Layer> child);
  91   void InsertChild(scoped_refptr<Layer> child, size_t index);
  92   void ReplaceChild(Layer* reference, scoped_refptr<Layer> new_layer);
  93   void RemoveFromParent();
  94   void RemoveAllChildren();
  95   void SetChildren(const LayerList& children);
  96   bool HasAncestor(const Layer* ancestor) const;
  97
  98   const LayerList& children() const { return children_; }
  99   Layer* child_at(size_t index) { return children_[index].get(); }
 100
 101   // This requests the layer and its subtree be rendered and given to the
 102   // callback. If the copy is unable to be produced (the layer is destroyed
 103   // first), then the callback is called with a nullptr/empty result. If the
 104   // request's source property is set, any prior uncommitted requests having the
 105   // same source will be aborted.
 106   void RequestCopyOfOutput(scoped_ptr<CopyOutputRequest> request);
 107   bool HasCopyRequest() const {
 108     return !copy_requests_.empty();
 109   }
 110
 111   virtual void SetBackgroundColor(SkColor background_color);
 112   SkColor background_color() const { return background_color_; }
 113   // If contents_opaque(), return an opaque color else return a
 114   // non-opaque color.  Tries to return background_color(), if possible.
 115   SkColor SafeOpaqueBackgroundColor() const;
 116
 117   // A layer's bounds are in logical, non-page-scaled pixels (however, the
 118   // root layer's bounds are in physical pixels).
 119   void SetBounds(const gfx::Size& bounds);
 120   gfx::Size bounds() const { return bounds_; }
 121
 122   void SetMasksToBounds(bool masks_to_bounds);
 123   bool masks_to_bounds() const { return masks_to_bounds_; }
 124
 125   void SetMaskLayer(Layer* mask_layer);
 126   Layer* mask_layer() { return mask_layer_.get(); }
 127   const Layer* mask_layer() const { return mask_layer_.get(); }
 128
 129   virtual void SetNeedsDisplayRect(const gfx::Rect& dirty_rect);
 130   void SetNeedsDisplay() { SetNeedsDisplayRect(gfx::Rect(bounds())); }
 131
 132   void SetOpacity(float opacity);
 133   float opacity() const { return opacity_; }
 134   bool OpacityIsAnimating() const;
 135   bool HasPotentiallyRunningOpacityAnimation() const;
 136   virtual bool OpacityCanAnimateOnImplThread() const;
 137
 138   void SetBlendMode(SkXfermode::Mode blend_mode);
 139   SkXfermode::Mode blend_mode() const { return blend_mode_; }
 140
 141   void set_draw_blend_mode(SkXfermode::Mode blend_mode) {
 142     if (draw_blend_mode_ == blend_mode)
 143       return;
 144     draw_blend_mode_ = blend_mode;
 145     SetNeedsPushProperties();
 146   }
 147   SkXfermode::Mode draw_blend_mode() const { return draw_blend_mode_; }
 148
 149   bool uses_default_blend_mode() const {
 150     return blend_mode_ == SkXfermode::kSrcOver_Mode;
 151   }
 152
 153   // A layer is root for an isolated group when it and all its descendants are
 154   // drawn over a black and fully transparent background, creating an isolated
 155   // group. It should be used along with SetBlendMode(), in order to restrict
 156   // layers within the group to blend with layers outside this group.
 157   void SetIsRootForIsolatedGroup(bool root);
 158   bool is_root_for_isolated_group() const {
 159     return is_root_for_isolated_group_;
 160   }
 161
 162   void SetFilters(const FilterOperations& filters);
 163   const FilterOperations& filters() const { return filters_; }
 164   bool FilterIsAnimating() const;
 165   bool HasPotentiallyRunningFilterAnimation() const;
 166
 167   // Background filters are filters applied to what is behind this layer, when
 168   // they are viewed through non-opaque regions in this layer. They are used
 169   // through the WebLayer interface, and are not exposed to HTML.
 170   void SetBackgroundFilters(const FilterOperations& filters);
 171   const FilterOperations& background_filters() const {
 172     return background_filters_;
 173   }
 174
 175   virtual void SetContentsOpaque(bool opaque);
 176   bool contents_opaque() const { return contents_opaque_; }
 177
 178   void SetPosition(const gfx::PointF& position);
 179   gfx::PointF position() const { return position_; }
 180
 181   // A layer that is a container for fixed position layers cannot be both
 182   // scrollable and have a non-identity transform.
 183   void SetIsContainerForFixedPositionLayers(bool container);
 184   bool IsContainerForFixedPositionLayers() const;
 185
 186   gfx::Vector2dF FixedContainerSizeDelta() const {
 187     return gfx::Vector2dF();
 188   }
 189
 190   void SetPositionConstraint(const LayerPositionConstraint& constraint);
 191   const LayerPositionConstraint& position_constraint() const {
 192     return position_constraint_;
 193   }
 194
 195   void SetTransform(const gfx::Transform& transform);
 196   const gfx::Transform& transform() const { return transform_; }
 197   bool TransformIsAnimating() const;
 198   bool HasPotentiallyRunningTransformAnimation() const;
 199   bool HasOnlyTranslationTransforms() const;
 200   bool AnimationsPreserveAxisAlignment() const;
 201   bool transform_is_invertible() const { return transform_is_invertible_; }
 202
 203   bool MaximumTargetScale(float* max_scale) const;
 204   bool AnimationStartScale(float* start_scale) const;
 205
 206   void SetTransformOrigin(const gfx::Point3F&);
 207   gfx::Point3F transform_origin() const { return transform_origin_; }
 208
 209   bool HasAnyAnimationTargetingProperty(
 210       Animation::TargetProperty property) const;
 211
 212   bool ScrollOffsetAnimationWasInterrupted() const;
 213
 214   void SetScrollParent(Layer* parent);
 215
 216   Layer* scroll_parent() { return scroll_parent_; }
 217   const Layer* scroll_parent() const { return scroll_parent_; }
 218
 219   void AddScrollChild(Layer* child);
 220   void RemoveScrollChild(Layer* child);
 221
 222   std::set<Layer*>* scroll_children() { return scroll_children_.get(); }
 223   const std::set<Layer*>* scroll_children() const {
 224     return scroll_children_.get();
 225   }
 226
 227   void SetClipParent(Layer* ancestor);
 228
 229   Layer* clip_parent() { return clip_parent_; }
 230   const Layer* clip_parent() const {
 231     return clip_parent_;
 232   }
 233
 234   void AddClipChild(Layer* child);
 235   void RemoveClipChild(Layer* child);
 236
 237   std::set<Layer*>* clip_children() { return clip_children_.get(); }
 238   const std::set<Layer*>* clip_children() const {
 239     return clip_children_.get();
 240   }
 241
 242   DrawProperties<Layer>& draw_properties() { return draw_properties_; }
 243   const DrawProperties<Layer>& draw_properties() const {
 244     return draw_properties_;
 245   }
 246
 247   // The following are shortcut accessors to get various information from
 248   // draw_properties_
 249   const gfx::Transform& draw_transform() const {
 250     return draw_properties_.target_space_transform;
 251   }
 252   const gfx::Transform& screen_space_transform() const {
 253     return draw_properties_.screen_space_transform;
 254   }
 255   float draw_opacity() const { return draw_properties_.opacity; }
 256   bool screen_space_transform_is_animating() const {
 257     return draw_properties_.screen_space_transform_is_animating;
 258   }
 259   gfx::Rect clip_rect() const { return draw_properties_.clip_rect; }
 260   gfx::Rect drawable_content_rect() const {
 261     return draw_properties_.drawable_content_rect;
 262   }
 263   gfx::Rect visible_layer_rect() const {
 264     return draw_properties_.visible_layer_rect;
 265   }
 266   Layer* render_target() {
 267     DCHECK(!draw_properties_.render_target ||
 268            draw_properties_.render_target->has_render_surface());
 269     return draw_properties_.render_target;
 270   }
 271   const Layer* render_target() const {
 272     DCHECK(!draw_properties_.render_target ||
 273            draw_properties_.render_target->has_render_surface());
 274     return draw_properties_.render_target;
 275   }
 276   size_t num_unclipped_descendants() const {
 277     return draw_properties_.num_unclipped_descendants;
 278   }
 279
 280   void SetScrollOffset(const gfx::ScrollOffset& scroll_offset);
 281   void SetScrollCompensationAdjustment(
 282       const gfx::Vector2dF& scroll_compensation_adjustment);
 283   gfx::Vector2dF ScrollCompensationAdjustment() const;
 284
 285   gfx::ScrollOffset scroll_offset() const { return scroll_offset_; }
 286   void SetScrollOffsetFromImplSide(const gfx::ScrollOffset& scroll_offset);
 287
 288   void SetScrollClipLayerId(int clip_layer_id);
 289   bool scrollable() const { return scroll_clip_layer_id_ != INVALID_ID; }
 290
 291   void SetUserScrollable(bool horizontal, bool vertical);
 292   bool user_scrollable_horizontal() const {
 293     return user_scrollable_horizontal_;
 294   }
 295   bool user_scrollable_vertical() const { return user_scrollable_vertical_; }
 296
 297   void SetShouldScrollOnMainThread(bool should_scroll_on_main_thread);
 298   bool should_scroll_on_main_thread() const {
 299     return should_scroll_on_main_thread_;
 300   }
 301
 302   void SetHaveWheelEventHandlers(bool have_wheel_event_handlers);
 303   bool have_wheel_event_handlers() const { return have_wheel_event_handlers_; }
 304
 305   void SetHaveScrollEventHandlers(bool have_scroll_event_handlers);
 306   bool have_scroll_event_handlers() const {
 307     return have_scroll_event_handlers_;
 308   }
 309
 310   void SetNonFastScrollableRegion(const Region& non_fast_scrollable_region);
 311   const Region& non_fast_scrollable_region() const {
 312     return non_fast_scrollable_region_;
 313   }
 314
 315   void SetTouchEventHandlerRegion(const Region& touch_event_handler_region);
 316   const Region& touch_event_handler_region() const {
 317     return touch_event_handler_region_;
 318   }
 319
 320   void SetScrollBlocksOn(ScrollBlocksOn scroll_blocks_on);
 321   ScrollBlocksOn scroll_blocks_on() const { return scroll_blocks_on_; }
 322
 323   void set_did_scroll_callback(const base::Closure& callback) {
 324     did_scroll_callback_ = callback;
 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 void SetIsMask(bool is_mask) {}
 380   virtual bool IsSuitableForGpuRasterization() const;
 381
 382   virtual scoped_refptr<base::trace_event::ConvertableToTraceFormat>
 383   TakeDebugInfo();
 384
 385   void SetLayerClient(LayerClient* client) { client_ = client; }
 386
 387   virtual void PushPropertiesTo(LayerImpl* layer);
 388
 389   LayerTreeHost* layer_tree_host() { return layer_tree_host_; }
 390   const LayerTreeHost* layer_tree_host() const { return layer_tree_host_; }
 391
 392   bool AddAnimation(scoped_ptr<Animation> animation);
 393   void PauseAnimation(int animation_id, double time_offset);
 394   void RemoveAnimation(int animation_id);
 395   void RemoveAnimation(int animation_id, Animation::TargetProperty property);
 396   LayerAnimationController* layer_animation_controller() const {
 397     return layer_animation_controller_.get();
 398   }
 399   void SetLayerAnimationControllerForTest(
 400       scoped_refptr<LayerAnimationController> controller);
 401
 402   void set_layer_animation_delegate(AnimationDelegate* delegate) {
 403     DCHECK(layer_animation_controller_);
 404     layer_animation_controller_->set_layer_animation_delegate(delegate);
 405   }
 406
 407   bool HasActiveAnimation() const;
 408   void RegisterForAnimations(AnimationRegistrar* registrar);
 409
 410   void AddLayerAnimationEventObserver(
 411       LayerAnimationEventObserver* animation_observer);
 412   void RemoveLayerAnimationEventObserver(
 413       LayerAnimationEventObserver* animation_observer);
 414
 415   virtual ScrollbarLayerInterface* ToScrollbarLayer();
 416
 417   virtual skia::RefPtr<SkPicture> GetPicture() const;
 418
 419   // Constructs a LayerImpl of the correct runtime type for this Layer type.
 420   virtual scoped_ptr<LayerImpl> CreateLayerImpl(LayerTreeImpl* tree_impl);
 421
 422   bool NeedsDisplayForTesting() const { return !update_rect_.IsEmpty(); }
 423   void ResetNeedsDisplayForTesting() { update_rect_ = gfx::Rect(); }
 424
 425   RenderingStatsInstrumentation* rendering_stats_instrumentation() const;
 426
 427   const PaintProperties& paint_properties() const {
 428     return paint_properties_;
 429   }
 430
 431   void SetNeedsPushProperties();
 432   bool needs_push_properties() const { return needs_push_properties_; }
 433   bool descendant_needs_push_properties() const {
 434     return num_dependents_need_push_properties_ > 0;
 435   }
 436   void reset_needs_push_properties_for_testing() {
 437     needs_push_properties_ = false;
 438   }
 439
 440   virtual void RunMicroBenchmark(MicroBenchmark* benchmark);
 441
 442   void Set3dSortingContextId(int id);
 443   int sorting_context_id() const { return sorting_context_id_; }
 444
 445   void set_property_tree_sequence_number(int sequence_number) {
 446     property_tree_sequence_number_ = sequence_number;
 447   }
 448
 449   void SetTransformTreeIndex(int index);
 450   int transform_tree_index() const;
 451
 452   void SetClipTreeIndex(int index);
 453   int clip_tree_index() const;
 454
 455   void SetEffectTreeIndex(int index);
 456   int effect_tree_index() const;
 457
 458   void set_offset_to_transform_parent(gfx::Vector2dF offset) {
 459     if (offset_to_transform_parent_ == offset)
 460       return;
 461     offset_to_transform_parent_ = offset;
 462     SetNeedsPushProperties();
 463   }
 464   gfx::Vector2dF offset_to_transform_parent() const {
 465     return offset_to_transform_parent_;
 466   }
 467
 468   // TODO(vollick): Once we transition to transform and clip trees, rename these
 469   // functions and related values.  The "from property trees" functions below
 470   // use the transform and clip trees.  Eventually, we will use these functions
 471   // to compute the official values, but these functions are retained for
 472   // testing purposes until we've migrated.
 473
 474   const gfx::Rect& visible_rect_from_property_trees() const {
 475     return visible_rect_from_property_trees_;
 476   }
 477   void set_visible_rect_from_property_trees(const gfx::Rect& rect) {
 478     // No push properties here, as this acts like a draw property.
 479     visible_rect_from_property_trees_ = rect;
 480   }
 481
 482   const gfx::Rect& clip_rect_in_target_space_from_property_trees() const {
 483     return clip_rect_in_target_space_from_property_trees_;
 484   }
 485   void set_clip_rect_in_target_space_from_property_trees(
 486       const gfx::Rect& rect) {
 487     clip_rect_in_target_space_from_property_trees_ = rect;
 488   }
 489
 490   void set_should_flatten_transform_from_property_tree(bool should_flatten) {
 491     if (should_flatten_transform_from_property_tree_ == should_flatten)
 492       return;
 493     should_flatten_transform_from_property_tree_ = should_flatten;
 494     SetNeedsPushProperties();
 495   }
 496   bool should_flatten_transform_from_property_tree() const {
 497     return should_flatten_transform_from_property_tree_;
 498   }
 499
 500   void set_is_clipped(bool is_clipped) {
 501     if (is_clipped_ == is_clipped)
 502       return;
 503     is_clipped_ = is_clipped;
 504     SetNeedsPushProperties();
 505   }
 506   bool is_clipped() const { return is_clipped_; }
 507
 508   bool has_render_surface() const {
 509     return has_render_surface_;
 510   }
 511
 512   // Sets new frame timing requests for this layer.
 513   void SetFrameTimingRequests(const std::vector<FrameTimingRequest>& requests);
 514
 515   // Accessor for unit tests
 516   const std::vector<FrameTimingRequest>& FrameTimingRequests() const {
 517     return frame_timing_requests_;
 518   }
 519
 520   void DidBeginTracing();
 521   void set_num_layer_or_descandant_with_copy_request(
 522       int num_layer_or_descendants_with_copy_request) {
 523     num_layer_or_descendants_with_copy_request_ =
 524         num_layer_or_descendants_with_copy_request;
 525   }
 526
 527   void set_num_children_with_scroll_parent(
 528       int num_children_with_scroll_parent) {
 529     num_children_with_scroll_parent_ = num_children_with_scroll_parent;
 530   }
 531
 532   int num_children_with_scroll_parent() {
 533     return num_children_with_scroll_parent_;
 534   }
 535
 536   void set_visited(bool visited);
 537   bool visited();
 538   void set_layer_or_descendant_is_drawn(bool layer_or_descendant_is_drawn);
 539   bool layer_or_descendant_is_drawn();
 540   void set_sorted_for_recursion(bool sorted_for_recursion);
 541   bool sorted_for_recursion();
 542
 543  protected:
 544   friend class LayerImpl;
 545   friend class TreeSynchronizer;
 546   ~Layer() override;
 547
 548   explicit Layer(const LayerSettings& settings);
 549
 550   // These SetNeeds functions are in order of severity of update:
 551   //
 552   // Called when this layer has been modified in some way, but isn't sure
 553   // that it needs a commit yet.  It needs CalcDrawProperties and UpdateLayers
 554   // before it knows whether or not a commit is required.
 555   void SetNeedsUpdate();
 556   // Called when a property has been modified in a way that the layer
 557   // knows immediately that a commit is required.  This implies SetNeedsUpdate
 558   // as well as SetNeedsPushProperties to push that property.
 559   void SetNeedsCommit();
 560   // This is identical to SetNeedsCommit, but the former requests a rebuild of
 561   // the property trees.
 562   void SetNeedsCommitNoRebuild();
 563   // Called when there's been a change in layer structure.  Implies both
 564   // SetNeedsUpdate and SetNeedsCommit, but not SetNeedsPushProperties.
 565   void SetNeedsFullTreeSync();
 566
 567   // Called when the next commit should wait until the pending tree is activated
 568   // before finishing the commit and unblocking the main thread. Used to ensure
 569   // unused resources on the impl thread are returned before commit completes.
 570   void SetNextCommitWaitsForActivation();
 571
 572   // Will recalculate whether the layer draws content and set draws_content_
 573   // appropriately.
 574   void UpdateDrawsContent(bool has_drawable_content);
 575   virtual bool HasDrawableContent() const;
 576
 577   // Called when the layer's number of drawable descendants changes.
 578   void AddDrawableDescendants(int num);
 579
 580   void AddDependentNeedsPushProperties();
 581   void RemoveDependentNeedsPushProperties();
 582   bool parent_should_know_need_push_properties() const {
 583     return needs_push_properties() || descendant_needs_push_properties();
 584   }
 585
 586   bool IsPropertyChangeAllowed() const;
 587
 588   // This flag is set when the layer needs to push properties to the impl
 589   // side.
 590   bool needs_push_properties_;
 591
 592   // The number of direct children or dependent layers that need to be recursed
 593   // to in order for them or a descendent of them to push properties to the impl
 594   // side.
 595   int num_dependents_need_push_properties_;
 596
 597   // Tracks whether this layer may have changed stacking order with its
 598   // siblings.
 599   bool stacking_order_changed_;
 600
 601   // The update rect is the region of the compositor resource that was
 602   // actually updated by the compositor. For layers that may do updating
 603   // outside the compositor's control (i.e. plugin layers), this information
 604   // is not available and the update rect will remain empty.
 605   // Note this rect is in layer space (not content space).
 606   gfx::Rect update_rect_;
 607
 608   scoped_refptr<Layer> mask_layer_;
 609
 610   int layer_id_;
 611
 612   // When true, the layer is about to perform an update. Any commit requests
 613   // will be handled implicitly after the update completes.
 614   bool ignore_set_needs_commit_;
 615
 616   // Layers that share a sorting context id will be sorted together in 3d
 617   // space.  0 is a special value that means this layer will not be sorted and
 618   // will be drawn in paint order.
 619   int sorting_context_id_;
 620
 621  private:
 622   friend class base::RefCounted<Layer>;
 623   friend class LayerTreeHostCommon;
 624   void SetParent(Layer* layer);
 625   bool DescendantIsFixedToContainerLayer() const;
 626
 627   // This should only be called during BeginMainFrame since it does not
 628   // trigger a Commit.
 629   void SetHasRenderSurface(bool has_render_surface);
 630
 631   // This should only be called from RemoveFromParent().
 632   void RemoveChildOrDependent(Layer* child);
 633
 634   // LayerAnimationValueProvider implementation.
 635   gfx::ScrollOffset ScrollOffsetForAnimation() const override;
 636
 637   // LayerAnimationValueObserver implementation.
 638   void OnFilterAnimated(const FilterOperations& filters) override;
 639   void OnOpacityAnimated(float opacity) override;
 640   void OnTransformAnimated(const gfx::Transform& transform) override;
 641   void OnScrollOffsetAnimated(const gfx::ScrollOffset& scroll_offset) override;
 642   void OnAnimationWaitingForDeletion() override;
 643   void OnTransformIsPotentiallyAnimatingChanged(bool is_animating) override;
 644   bool IsActive() const override;
 645
 646   // If this layer has a scroll parent, it removes |this| from its list of
 647   // scroll children.
 648   void RemoveFromScrollTree();
 649
 650   // If this layer has a clip parent, it removes |this| from its list of clip
 651   // children.
 652   void RemoveFromClipTree();
 653
 654   // When we detach or attach layer to new LayerTreeHost, all property trees'
 655   // indices becomes invalid.
 656   void InvalidatePropertyTreesIndices();
 657
 658   void UpdateNumCopyRequestsForSubtree(bool add);
 659
 660   LayerList children_;
 661   Layer* parent_;
 662
 663   // Layer instances have a weak pointer to their LayerTreeHost.
 664   // This pointer value is nil when a Layer is not in a tree and is
 665   // updated via SetLayerTreeHost() if a layer moves between trees.
 666   LayerTreeHost* layer_tree_host_;
 667
 668   scoped_refptr<LayerAnimationController> layer_animation_controller_;
 669
 670   // Layer properties.
 671   gfx::Size bounds_;
 672
 673   gfx::ScrollOffset scroll_offset_;
 674   gfx::Vector2dF scroll_compensation_adjustment_;
 675   // This variable indicates which ancestor layer (if any) whose size,
 676   // transformed relative to this layer, defines the maximum scroll offset for
 677   // this layer.
 678   int scroll_clip_layer_id_;
 679   int num_descendants_that_draw_content_;
 680   int transform_tree_index_;
 681   int effect_tree_index_;
 682   int clip_tree_index_;
 683   int property_tree_sequence_number_;
 684   int num_layer_or_descendants_with_copy_request_;
 685   int num_children_with_scroll_parent_;
 686   gfx::Vector2dF offset_to_transform_parent_;
 687   bool should_flatten_transform_from_property_tree_ : 1;
 688   bool is_clipped_ : 1;
 689   bool should_scroll_on_main_thread_ : 1;
 690   bool have_wheel_event_handlers_ : 1;
 691   bool have_scroll_event_handlers_ : 1;
 692   bool user_scrollable_horizontal_ : 1;
 693   bool user_scrollable_vertical_ : 1;
 694   bool is_root_for_isolated_group_ : 1;
 695   bool is_container_for_fixed_position_layers_ : 1;
 696   bool is_drawable_ : 1;
 697   bool draws_content_ : 1;
 698   bool hide_layer_and_subtree_ : 1;
 699   bool masks_to_bounds_ : 1;
 700   bool contents_opaque_ : 1;
 701   bool double_sided_ : 1;
 702   bool should_flatten_transform_ : 1;
 703   bool use_parent_backface_visibility_ : 1;
 704   bool force_render_surface_ : 1;
 705   bool transform_is_invertible_ : 1;
 706   bool has_render_surface_ : 1;
 707   ScrollBlocksOn scroll_blocks_on_ : 3;
 708   Region non_fast_scrollable_region_;
 709   Region touch_event_handler_region_;
 710   gfx::PointF position_;
 711   SkColor background_color_;
 712   float opacity_;
 713   SkXfermode::Mode blend_mode_;
 714   // draw_blend_mode may be different than blend_mode_,
 715   // when a RenderSurface re-parents the layer's blend_mode.
 716   SkXfermode::Mode draw_blend_mode_;
 717   FilterOperations filters_;
 718   FilterOperations background_filters_;
 719   LayerPositionConstraint position_constraint_;
 720   Layer* scroll_parent_;
 721   scoped_ptr<std::set<Layer*>> scroll_children_;
 722
 723   // The following three variables are tracker variables. They are bools
 724   // wrapped inside an integer variable. If true, their value equals the
 725   // LayerTreeHost's meta_information_sequence_number. This wrapping of bools
 726   // inside ints is done to avoid a layer tree treewalk to reset their values.
 727   int layer_or_descendant_is_drawn_tracker_;
 728   int sorted_for_recursion_tracker_;
 729   int visited_tracker_;
 730
 731   Layer* clip_parent_;
 732   scoped_ptr<std::set<Layer*>> clip_children_;
 733
 734   gfx::Transform transform_;
 735   gfx::Point3F transform_origin_;
 736
 737   // Replica layer used for reflections.
 738   scoped_refptr<Layer> replica_layer_;
 739
 740   LayerClient* client_;
 741
 742   ScopedPtrVector<CopyOutputRequest> copy_requests_;
 743
 744   base::Closure did_scroll_callback_;
 745
 746   DrawProperties<Layer> draw_properties_;
 747
 748   PaintProperties paint_properties_;
 749
 750   gfx::Rect visible_rect_from_property_trees_;
 751   gfx::Rect clip_rect_in_target_space_from_property_trees_;
 752
 753   std::vector<FrameTimingRequest> frame_timing_requests_;
 754   bool frame_timing_requests_dirty_;
 755
 756   DISALLOW_COPY_AND_ASSIGN(Layer);
 757 };
 758
 759 }  // namespace cc
 760
 761 #endif  // CC_LAYERS_LAYER_H_