cc/trees/layer_tree_impl.h

// Copyright 2012 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef CC_TREES_LAYER_TREE_IMPL_H_
#define CC_TREES_LAYER_TREE_IMPL_H_

#include <set>
#include <string>
#include <vector>

#include "base/containers/hash_tables.h"
#include "base/values.h"
#include "cc/base/scoped_ptr_vector.h"
#include "cc/base/synced_property.h"
#include "cc/input/layer_selection_bound.h"
#include "cc/layers/layer_impl.h"
#include "cc/output/begin_frame_args.h"
#include "cc/output/renderer.h"
#include "cc/output/swap_promise.h"
#include "cc/resources/ui_resource_client.h"
#include "cc/trees/layer_tree_host_impl.h"

namespace base {
namespace trace_event {
class TracedValue;
}
}

namespace cc {

class ContextProvider;
class DebugRectHistory;
class FrameRateCounter;
class HeadsUpDisplayLayerImpl;
class LayerScrollOffsetDelegateProxy;
class LayerTreeDebugState;
class LayerTreeImpl;
class LayerTreeSettings;
class MemoryHistory;
class OutputSurface;
class PageScaleAnimation;
class PaintTimeCounter;
class PictureLayerImpl;
class Proxy;
class ResourceProvider;
class TileManager;
class UIResourceRequest;
struct PendingPageScaleAnimation;
struct RendererCapabilities;
struct SelectionHandle;

typedef std::vector<UIResourceRequest> UIResourceRequestQueue;
typedef SyncedProperty<AdditionGroup<float>> SyncedTopControls;
typedef SyncedProperty<AdditionGroup<gfx::Vector2dF>> SyncedElasticOverscroll;

class CC_EXPORT LayerTreeImpl {
 public:
  static scoped_ptr<LayerTreeImpl> create(
      LayerTreeHostImpl* layer_tree_host_impl,
      scoped_refptr<SyncedProperty<ScaleGroup>> page_scale_factor,
      scoped_refptr<SyncedTopControls> top_controls_shown_ratio,
      scoped_refptr<SyncedElasticOverscroll> elastic_overscroll) {
    return make_scoped_ptr(
        new LayerTreeImpl(layer_tree_host_impl, page_scale_factor,
                          top_controls_shown_ratio, elastic_overscroll));
  }
  virtual ~LayerTreeImpl();

  void Shutdown();
  void ReleaseResources();
  void RecreateResources();

  // Methods called by the layer tree that pass-through or access LTHI.
  // ---------------------------------------------------------------------------
  const LayerTreeSettings& settings() const;
  const LayerTreeDebugState& debug_state() const;
  const RendererCapabilitiesImpl& GetRendererCapabilities() const;
  ContextProvider* context_provider() const;
  OutputSurface* output_surface() const;
  ResourceProvider* resource_provider() const;
  TileManager* tile_manager() const;
  FrameRateCounter* frame_rate_counter() const;
  PaintTimeCounter* paint_time_counter() const;
  MemoryHistory* memory_history() const;
  gfx::Size device_viewport_size() const;
  float device_scale_factor() const;
  DebugRectHistory* debug_rect_history() const;
  bool IsActiveTree() const;
  bool IsPendingTree() const;
  bool IsRecycleTree() const;
  bool IsSyncTree() const;
  LayerImpl* FindActiveTreeLayerById(int id);
  LayerImpl* FindPendingTreeLayerById(int id);
  bool PinchGestureActive() const;
  BeginFrameArgs CurrentBeginFrameArgs() const;
  base::TimeDelta begin_impl_frame_interval() const;
  void SetNeedsCommit();
  gfx::Rect DeviceViewport() const;
  gfx::Size DrawViewportSize() const;
  const gfx::Rect ViewportRectForTilePriority() const;
  scoped_ptr<ScrollbarAnimationController> CreateScrollbarAnimationController(
      LayerImpl* scrolling_layer);
  void DidAnimateScrollOffset();
  void InputScrollAnimationFinished();
  bool use_gpu_rasterization() const;
  GpuRasterizationStatus GetGpuRasterizationStatus() const;
  bool create_low_res_tiling() const;
  BlockingTaskRunner* BlockingMainThreadTaskRunner() const;
  bool RequiresHighResToDraw() const;
  bool SmoothnessTakesPriority() const;

  // Tree specific methods exposed to layer-impl tree.
  // ---------------------------------------------------------------------------
  void SetNeedsRedraw();

  // Tracing methods.
  // ---------------------------------------------------------------------------
  void GetAllTilesForTracing(std::set<const Tile*>* tiles) const;
  void AsValueInto(base::trace_event::TracedValue* dict) const;

  // Other public methods
  // ---------------------------------------------------------------------------
  LayerImpl* root_layer() const { return root_layer_.get(); }
  void SetRootLayer(scoped_ptr<LayerImpl>);
  scoped_ptr<LayerImpl> DetachLayerTree();

  void PushPropertiesTo(LayerTreeImpl* tree_impl);

  int source_frame_number() const { return source_frame_number_; }
  void set_source_frame_number(int frame_number) {
    source_frame_number_ = frame_number;
  }

  HeadsUpDisplayLayerImpl* hud_layer() { return hud_layer_; }
  void set_hud_layer(HeadsUpDisplayLayerImpl* layer_impl) {
    hud_layer_ = layer_impl;
  }

  LayerImpl* InnerViewportScrollLayer() const;
  // This function may return NULL, it is the caller's responsibility to check.
  LayerImpl* OuterViewportScrollLayer() const;
  gfx::ScrollOffset TotalScrollOffset() const;
  gfx::ScrollOffset TotalMaxScrollOffset() const;

  LayerImpl* InnerViewportContainerLayer() const;
  LayerImpl* OuterViewportContainerLayer() const;
  LayerImpl* CurrentlyScrollingLayer() const;
  void SetCurrentlyScrollingLayer(LayerImpl* layer);
  void ClearCurrentlyScrollingLayer();

  void SetViewportLayersFromIds(int overscroll_elasticity_layer,
                                int page_scale_layer_id,
                                int inner_viewport_scroll_layer_id,
                                int outer_viewport_scroll_layer_id);
  void ClearViewportLayers();
  LayerImpl* overscroll_elasticity_layer() {
    return overscroll_elasticity_layer_;
  }
  LayerImpl* page_scale_layer() { return page_scale_layer_; }
  void ApplySentScrollAndScaleDeltasFromAbortedCommit();

  SkColor background_color() const { return background_color_; }
  void set_background_color(SkColor color) { background_color_ = color; }

  bool has_transparent_background() const {
    return has_transparent_background_;
  }
  void set_has_transparent_background(bool transparent) {
    has_transparent_background_ = transparent;
  }

  void SetPageScaleOnActiveTree(float active_page_scale);
  void PushPageScaleFromMainThread(float page_scale_factor,
                                   float min_page_scale_factor,
                                   float max_page_scale_factor);
  float current_page_scale_factor() const {
    return page_scale_factor()->Current(IsActiveTree());
  }
  float min_page_scale_factor() const { return min_page_scale_factor_; }
  float max_page_scale_factor() const { return max_page_scale_factor_; }

  float page_scale_delta() const { return page_scale_factor()->Delta(); }

  SyncedProperty<ScaleGroup>* page_scale_factor();
  const SyncedProperty<ScaleGroup>* page_scale_factor() const;

  SyncedElasticOverscroll* elastic_overscroll() {
    return elastic_overscroll_.get();
  }
  const SyncedElasticOverscroll* elastic_overscroll() const {
    return elastic_overscroll_.get();
  }

  SyncedTopControls* top_controls_shown_ratio() {
    return top_controls_shown_ratio_.get();
  }
  const SyncedTopControls* top_controls_shown_ratio() const {
    return top_controls_shown_ratio_.get();
  }

  // Updates draw properties and render surface layer list, as well as tile
  // priorities. Returns false if it was unable to update.  Updating lcd
  // text may cause invalidations, so should only be done after a commit.
  bool UpdateDrawProperties(bool update_lcd_text);

  void set_needs_update_draw_properties() {
    needs_update_draw_properties_ = true;
  }
  bool needs_update_draw_properties() const {
    return needs_update_draw_properties_;
  }

  void set_needs_full_tree_sync(bool needs) { needs_full_tree_sync_ = needs; }
  bool needs_full_tree_sync() const { return needs_full_tree_sync_; }

  void ForceRedrawNextActivation() { next_activation_forces_redraw_ = true; }

  void set_has_ever_been_drawn(bool has_drawn) {
    has_ever_been_drawn_ = has_drawn;
  }
  bool has_ever_been_drawn() const { return has_ever_been_drawn_; }

  void set_ui_resource_request_queue(const UIResourceRequestQueue& queue);

  const LayerImplList& RenderSurfaceLayerList() const;
  const Region& UnoccludedScreenSpaceRegion() const;

  // These return the size of the root scrollable area and the size of
  // the user-visible scrolling viewport, in CSS layout coordinates.
  gfx::Size ScrollableSize() const;
  gfx::SizeF ScrollableViewportSize() const;

  gfx::Rect RootScrollLayerDeviceViewportBounds() const;

  LayerImpl* LayerById(int id);

  // These should be called by LayerImpl's ctor/dtor.
  void RegisterLayer(LayerImpl* layer);
  void UnregisterLayer(LayerImpl* layer);

  size_t NumLayers();

  AnimationRegistrar* GetAnimationRegistrar() const;

  void PushPersistedState(LayerTreeImpl* pending_tree);

  void DidBecomeActive();

  bool ContentsTexturesPurged() const;
  void SetContentsTexturesPurged();
  void ResetContentsTexturesPurged();

  // Set on the active tree when the viewport size recently changed
  // and the active tree's size is now out of date.
  bool ViewportSizeInvalid() const;
  void SetViewportSizeInvalid();
  void ResetViewportSizeInvalid();

  // Useful for debug assertions, probably shouldn't be used for anything else.
  Proxy* proxy() const;

  void SetRootLayerScrollOffsetDelegate(
      LayerScrollOffsetDelegate* root_layer_scroll_offset_delegate);
  void OnRootLayerDelegatedScrollOffsetChanged();
  void UpdateScrollOffsetDelegate();
  gfx::ScrollOffset GetDelegatedScrollOffset(LayerImpl* layer);

  // Call this function when you expect there to be a swap buffer.
  // See swap_promise.h for how to use SwapPromise.
  void QueueSwapPromise(scoped_ptr<SwapPromise> swap_promise);

  // Take the |new_swap_promise| and append it to |swap_promise_list_|.
  void PassSwapPromises(ScopedPtrVector<SwapPromise>* new_swap_promise);
  void FinishSwapPromises(CompositorFrameMetadata* metadata);
  void BreakSwapPromises(SwapPromise::DidNotSwapReason reason);

  void DidModifyTilePriorities();

  ResourceProvider::ResourceId ResourceIdForUIResource(UIResourceId uid) const;
  void ProcessUIResourceRequestQueue();

  bool IsUIResourceOpaque(UIResourceId uid) const;

  void RegisterPictureLayerImpl(PictureLayerImpl* layer);
  void UnregisterPictureLayerImpl(PictureLayerImpl* layer);
  const std::vector<PictureLayerImpl*>& picture_layers() const {
    return picture_layers_;
  }

  void AddLayerWithCopyOutputRequest(LayerImpl* layer);
  void RemoveLayerWithCopyOutputRequest(LayerImpl* layer);
  const std::vector<LayerImpl*>& LayersWithCopyOutputRequest() const;

  int current_render_surface_list_id() const {
    return render_surface_layer_list_id_;
  }

  LayerImpl* FindFirstScrollingLayerThatIsHitByPoint(
      const gfx::PointF& screen_space_point);

  LayerImpl* FindLayerThatIsHitByPoint(const gfx::PointF& screen_space_point);

  LayerImpl* FindLayerWithWheelHandlerThatIsHitByPoint(
      const gfx::PointF& screen_space_point);

  LayerImpl* FindLayerThatIsHitByPointInTouchHandlerRegion(
      const gfx::PointF& screen_space_point);

  void RegisterSelection(const LayerSelectionBound& start,
                         const LayerSelectionBound& end);

  // Compute the current selection handle location and visbility with respect to
  // the viewport.
  void GetViewportSelection(ViewportSelectionBound* start,
                            ViewportSelectionBound* end);

  void set_top_controls_shrink_blink_size(bool shrink);
  bool top_controls_shrink_blink_size() const {
    return top_controls_shrink_blink_size_;
  }
  bool SetCurrentTopControlsShownRatio(float ratio);
  float CurrentTopControlsShownRatio() const {
    return top_controls_shown_ratio_->Current(IsActiveTree());
  }
  void set_top_controls_height(float top_controls_height);
  float top_controls_height() const { return top_controls_height_; }
  void PushTopControlsFromMainThread(float top_controls_shown_ratio);

  void SetPendingPageScaleAnimation(
      scoped_ptr<PendingPageScaleAnimation> pending_animation);
  scoped_ptr<PendingPageScaleAnimation> TakePendingPageScaleAnimation();

 protected:
  explicit LayerTreeImpl(
      LayerTreeHostImpl* layer_tree_host_impl,
      scoped_refptr<SyncedProperty<ScaleGroup>> page_scale_factor,
      scoped_refptr<SyncedTopControls> top_controls_shown_ratio,
      scoped_refptr<SyncedElasticOverscroll> elastic_overscroll);
  float ClampPageScaleFactorToLimits(float page_scale_factor) const;
  void PushPageScaleFactorAndLimits(const float* page_scale_factor,
                                    float min_page_scale_factor,
                                    float max_page_scale_factor);
  bool SetPageScaleFactorLimits(float min_page_scale_factor,
                                float max_page_scale_factor);
  void DidUpdatePageScale();
  void HideInnerViewportScrollbarsIfNearMinimumScale();
  void PushTopControls(const float* top_controls_shown_ratio);
  LayerTreeHostImpl* layer_tree_host_impl_;
  int source_frame_number_;
  scoped_ptr<LayerImpl> root_layer_;
  HeadsUpDisplayLayerImpl* hud_layer_;
  LayerImpl* currently_scrolling_layer_;
  LayerScrollOffsetDelegate* root_layer_scroll_offset_delegate_;
  scoped_ptr<LayerScrollOffsetDelegateProxy>
      inner_viewport_scroll_delegate_proxy_;
  scoped_ptr<LayerScrollOffsetDelegateProxy>
      outer_viewport_scroll_delegate_proxy_;
  SkColor background_color_;
  bool has_transparent_background_;

  LayerImpl* overscroll_elasticity_layer_;
  LayerImpl* page_scale_layer_;
  LayerImpl* inner_viewport_scroll_layer_;
  LayerImpl* outer_viewport_scroll_layer_;

  LayerSelectionBound selection_start_;
  LayerSelectionBound selection_end_;

  scoped_refptr<SyncedProperty<ScaleGroup>> page_scale_factor_;
  float min_page_scale_factor_;
  float max_page_scale_factor_;

  scoped_refptr<SyncedElasticOverscroll> elastic_overscroll_;

  typedef base::hash_map<int, LayerImpl*> LayerIdMap;
  LayerIdMap layer_id_map_;

  std::vector<PictureLayerImpl*> picture_layers_;
  std::vector<LayerImpl*> layers_with_copy_output_request_;

  // Persisted state for non-impl-side-painting.
  int scrolling_layer_id_from_previous_tree_;

  // List of visible layers for the most recently prepared frame.
  LayerImplList render_surface_layer_list_;
  // After drawing the |render_surface_layer_list_| the areas in this region
  // would not be fully covered by opaque content.
  Region unoccluded_screen_space_region_;

  bool contents_textures_purged_;
  bool viewport_size_invalid_;
  bool needs_update_draw_properties_;

  // In impl-side painting mode, this is true when the tree may contain
  // structural differences relative to the active tree.
  bool needs_full_tree_sync_;

  bool next_activation_forces_redraw_;

  bool has_ever_been_drawn_;

  ScopedPtrVector<SwapPromise> swap_promise_list_;

  UIResourceRequestQueue ui_resource_request_queue_;

  int render_surface_layer_list_id_;

  // Whether or not Blink's viewport size was shrunk by the height of the top
  // controls at the time of the last layout.
  bool top_controls_shrink_blink_size_;

  float top_controls_height_;

  // The amount that the top controls are shown from 0 (hidden) to 1 (fully
  // shown).
  scoped_refptr<SyncedTopControls> top_controls_shown_ratio_;

  scoped_ptr<PendingPageScaleAnimation> pending_page_scale_animation_;

 private:
  DISALLOW_COPY_AND_ASSIGN(LayerTreeImpl);
};

}  // namespace cc

#endif  // CC_TREES_LAYER_TREE_IMPL_H_