cc/trees/layer_tree_host.h

// Copyright 2011 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_HOST_H_
#define CC_TREES_LAYER_TREE_HOST_H_

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

#include "base/basictypes.h"
#include "base/cancelable_callback.h"
#include "base/containers/hash_tables.h"
#include "base/memory/ref_counted.h"
#include "base/memory/scoped_ptr.h"
#include "base/memory/weak_ptr.h"
#include "base/time/time.h"
#include "base/timer/timer.h"
#include "cc/animation/animation_events.h"
#include "cc/base/cc_export.h"
#include "cc/base/scoped_ptr_vector.h"
#include "cc/base/swap_promise.h"
#include "cc/base/swap_promise_monitor.h"
#include "cc/debug/micro_benchmark.h"
#include "cc/debug/micro_benchmark_controller.h"
#include "cc/input/input_handler.h"
#include "cc/input/layer_selection_bound.h"
#include "cc/input/scrollbar.h"
#include "cc/input/top_controls_state.h"
#include "cc/layers/layer_lists.h"
#include "cc/output/output_surface.h"
#include "cc/resources/resource_format.h"
#include "cc/resources/scoped_ui_resource.h"
#include "cc/surfaces/surface_sequence.h"
#include "cc/trees/layer_tree_host_client.h"
#include "cc/trees/layer_tree_host_common.h"
#include "cc/trees/layer_tree_settings.h"
#include "cc/trees/proxy.h"
#include "third_party/skia/include/core/SkColor.h"
#include "ui/gfx/geometry/rect.h"

namespace gpu {
class GpuMemoryBufferManager;
}

namespace cc {
class AnimationRegistrar;
class BeginFrameSource;
class HeadsUpDisplayLayer;
class Layer;
class LayerTreeHostImpl;
class LayerTreeHostImplClient;
class LayerTreeHostSingleThreadClient;
class PrioritizedResource;
class PrioritizedResourceManager;
class Region;
class RenderingStatsInstrumentation;
class ResourceProvider;
class ResourceUpdateQueue;
class SharedBitmapManager;
class TopControlsManager;
class UIResourceRequest;
struct PendingPageScaleAnimation;
struct RenderingStats;
struct ScrollAndScaleSet;
enum class GpuRasterizationStatus;

// Provides information on an Impl's rendering capabilities back to the
// LayerTreeHost.
struct CC_EXPORT RendererCapabilities {
  RendererCapabilities(ResourceFormat best_texture_format,
                       bool allow_partial_texture_updates,
                       int max_texture_size,
                       bool using_shared_memory_resources);

  RendererCapabilities();
  ~RendererCapabilities();

  // Duplicate any modification to this list to RendererCapabilitiesImpl.
  ResourceFormat best_texture_format;
  bool allow_partial_texture_updates;
  int max_texture_size;
  bool using_shared_memory_resources;
};

class CC_EXPORT LayerTreeHost {
 public:
  // The SharedBitmapManager will be used on the compositor thread.
  static scoped_ptr<LayerTreeHost> CreateThreaded(
      LayerTreeHostClient* client,
      SharedBitmapManager* shared_bitmap_manager,
      gpu::GpuMemoryBufferManager* gpu_memory_buffer_manager,
      const LayerTreeSettings& settings,
      scoped_refptr<base::SingleThreadTaskRunner> main_task_runner,
      scoped_refptr<base::SingleThreadTaskRunner> impl_task_runner,
      scoped_ptr<BeginFrameSource> external_begin_frame_source);

  static scoped_ptr<LayerTreeHost> CreateSingleThreaded(
      LayerTreeHostClient* client,
      LayerTreeHostSingleThreadClient* single_thread_client,
      SharedBitmapManager* shared_bitmap_manager,
      gpu::GpuMemoryBufferManager* gpu_memory_buffer_manager,
      const LayerTreeSettings& settings,
      scoped_refptr<base::SingleThreadTaskRunner> main_task_runner,
      scoped_ptr<BeginFrameSource> external_begin_frame_source);
  virtual ~LayerTreeHost();

  void SetLayerTreeHostClientReady();

  // LayerTreeHost interface to Proxy.
  void WillBeginMainFrame();
  void DidBeginMainFrame();
  void BeginMainFrame(const BeginFrameArgs& args);
  void AnimateLayers(base::TimeTicks monotonic_frame_begin_time);
  void DidStopFlinging();
  void Layout();
  void BeginCommitOnImplThread(LayerTreeHostImpl* host_impl);
  void FinishCommitOnImplThread(LayerTreeHostImpl* host_impl);
  void WillCommit();
  void CommitComplete();
  void SetOutputSurface(scoped_ptr<OutputSurface> output_surface);
  void RequestNewOutputSurface();
  void DidInitializeOutputSurface();
  void DidFailToInitializeOutputSurface();
  virtual scoped_ptr<LayerTreeHostImpl> CreateLayerTreeHostImpl(
      LayerTreeHostImplClient* client);
  void DidLoseOutputSurface();
  bool output_surface_lost() const { return output_surface_lost_; }
  void DidCommitAndDrawFrame() { client_->DidCommitAndDrawFrame(); }
  void DidCompleteSwapBuffers() { client_->DidCompleteSwapBuffers(); }
  void DeleteContentsTexturesOnImplThread(ResourceProvider* resource_provider);
  bool UpdateLayers(ResourceUpdateQueue* queue);

  // Called when the compositor completed page scale animation.
  void DidCompletePageScaleAnimation();

  LayerTreeHostClient* client() { return client_; }
  const base::WeakPtr<InputHandler>& GetInputHandler() {
    return input_handler_weak_ptr_;
  }

  void NotifyInputThrottledUntilCommit();

  void Composite(base::TimeTicks frame_begin_time);

  void FinishAllRendering();

  void SetDeferCommits(bool defer_commits);

  int source_frame_number() const { return source_frame_number_; }

  void SetNeedsDisplayOnAllLayers();

  void CollectRenderingStats(RenderingStats* stats) const;

  RenderingStatsInstrumentation* rendering_stats_instrumentation() const {
    return rendering_stats_instrumentation_.get();
  }

  const RendererCapabilities& GetRendererCapabilities() const;

  void SetNeedsAnimate();
  virtual void SetNeedsUpdateLayers();
  virtual void SetNeedsCommit();
  virtual void SetNeedsFullTreeSync();
  void SetNeedsRedraw();
  void SetNeedsRedrawRect(const gfx::Rect& damage_rect);
  bool CommitRequested() const;
  bool BeginMainFrameRequested() const;

  void SetNextCommitWaitsForActivation();

  void SetNextCommitForcesRedraw();

  void SetAnimationEvents(scoped_ptr<AnimationEventsVector> events);

  void SetRootLayer(scoped_refptr<Layer> root_layer);
  Layer* root_layer() { return root_layer_.get(); }
  const Layer* root_layer() const { return root_layer_.get(); }
  const Layer* overscroll_elasticity_layer() const {
    return overscroll_elasticity_layer_.get();
  }
  const Layer* page_scale_layer() const { return page_scale_layer_.get(); }
  void RegisterViewportLayers(scoped_refptr<Layer> overscroll_elasticity_layer,
                              scoped_refptr<Layer> page_scale_layer,
                              scoped_refptr<Layer> inner_viewport_scroll_layer,
                              scoped_refptr<Layer> outer_viewport_scroll_layer);
  Layer* inner_viewport_scroll_layer() const {
    return inner_viewport_scroll_layer_.get();
  }
  Layer* outer_viewport_scroll_layer() const {
    return outer_viewport_scroll_layer_.get();
  }

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

  const LayerTreeSettings& settings() const { return settings_; }

  void SetDebugState(const LayerTreeDebugState& debug_state);
  const LayerTreeDebugState& debug_state() const { return debug_state_; }

  bool has_gpu_rasterization_trigger() const {
    return has_gpu_rasterization_trigger_;
  }
  void SetHasGpuRasterizationTrigger(bool has_trigger);
  bool UseGpuRasterization() const;
  GpuRasterizationStatus GetGpuRasterizationStatus() const;

  void SetViewportSize(const gfx::Size& device_viewport_size);
  void SetTopControlsShrinkBlinkSize(bool shrink);
  void SetTopControlsHeight(float height);
  void SetTopControlsShownRatio(float ratio);

  gfx::Size device_viewport_size() const { return device_viewport_size_; }

  void ApplyPageScaleDeltaFromImplSide(float page_scale_delta);
  void SetPageScaleFactorAndLimits(float page_scale_factor,
                                   float min_page_scale_factor,
                                   float max_page_scale_factor);
  float page_scale_factor() const { return page_scale_factor_; }
  gfx::Vector2dF elastic_overscroll() const { return elastic_overscroll_; }

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

  void set_has_transparent_background(bool transparent) {
    has_transparent_background_ = transparent;
  }

  PrioritizedResourceManager* contents_texture_manager() const {
    return contents_texture_manager_.get();
  }

  void SetVisible(bool visible);
  bool visible() const { return visible_; }

  void SetThrottleFrameProduction(bool throttle);

  void StartPageScaleAnimation(const gfx::Vector2d& target_offset,
                               bool use_anchor,
                               float scale,
                               base::TimeDelta duration);

  void ApplyScrollAndScale(ScrollAndScaleSet* info);
  void SetImplTransform(const gfx::Transform& transform);

  // Virtual for tests.
  virtual void StartRateLimiter();
  virtual void StopRateLimiter();

  void RateLimit();

  bool AlwaysUsePartialTextureUpdates();
  size_t MaxPartialTextureUpdates() const;
  bool RequestPartialTextureUpdate();

  void SetDeviceScaleFactor(float device_scale_factor);
  float device_scale_factor() const { return device_scale_factor_; }

  void UpdateTopControlsState(TopControlsState constraints,
                              TopControlsState current,
                              bool animate);

  HeadsUpDisplayLayer* hud_layer() const { return hud_layer_.get(); }

  Proxy* proxy() const { return proxy_.get(); }

  AnimationRegistrar* animation_registrar() const {
    return animation_registrar_.get();
  }

  // Obtains a thorough dump of the LayerTreeHost as a value.
  void AsValueInto(base::trace_event::TracedValue* value) const;

  bool in_paint_layer_contents() const { return in_paint_layer_contents_; }

  // CreateUIResource creates a resource given a bitmap.  The bitmap is
  // generated via an interface function, which is called when initializing the
  // resource and when the resource has been lost (due to lost context).  The
  // parameter of the interface is a single boolean, which indicates whether the
  // resource has been lost or not.  CreateUIResource returns an Id of the
  // resource, which is always positive.
  virtual UIResourceId CreateUIResource(UIResourceClient* client);
  // Deletes a UI resource.  May safely be called more than once.
  virtual void DeleteUIResource(UIResourceId id);
  // Put the recreation of all UI resources into the resource queue after they
  // were evicted on the impl thread.
  void RecreateUIResources();

  virtual gfx::Size GetUIResourceSize(UIResourceId id) const;

  bool UsingSharedMemoryResources();
  int id() const { return id_; }

  // Returns the id of the benchmark on success, 0 otherwise.
  int ScheduleMicroBenchmark(const std::string& benchmark_name,
                             scoped_ptr<base::Value> value,
                             const MicroBenchmark::DoneCallback& callback);
  // Returns true if the message was successfully delivered and handled.
  bool SendMessageToMicroBenchmark(int id, scoped_ptr<base::Value> value);

  // When a SwapPromiseMonitor is created on the main thread, it calls
  // InsertSwapPromiseMonitor() to register itself with LayerTreeHost.
  // When the monitor is destroyed, it calls RemoveSwapPromiseMonitor()
  // to unregister itself.
  void InsertSwapPromiseMonitor(SwapPromiseMonitor* monitor);
  void RemoveSwapPromiseMonitor(SwapPromiseMonitor* monitor);

  // 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);

  void BreakSwapPromises(SwapPromise::DidNotSwapReason reason);

  size_t num_queued_swap_promises() const { return swap_promise_list_.size(); }

  void set_surface_id_namespace(uint32_t id_namespace);
  SurfaceSequence CreateSurfaceSequence();

  void SetChildrenNeedBeginFrames(bool children_need_begin_frames) const;
  void SendBeginFramesToChildren(const BeginFrameArgs& args) const;

 protected:
  LayerTreeHost(LayerTreeHostClient* client,
                SharedBitmapManager* shared_bitmap_manager,
                gpu::GpuMemoryBufferManager* gpu_memory_buffer_manager,
                const LayerTreeSettings& settings);
  void InitializeThreaded(
      scoped_refptr<base::SingleThreadTaskRunner> main_task_runner,
      scoped_refptr<base::SingleThreadTaskRunner> impl_task_runner,
      scoped_ptr<BeginFrameSource> external_begin_frame_source);
  void InitializeSingleThreaded(
      LayerTreeHostSingleThreadClient* single_thread_client,
      scoped_refptr<base::SingleThreadTaskRunner> main_task_runner,
      scoped_ptr<BeginFrameSource> external_begin_frame_source);
  void InitializeForTesting(scoped_ptr<Proxy> proxy_for_testing);
  void SetOutputSurfaceLostForTesting(bool is_lost) {
    output_surface_lost_ = is_lost;
  }

  MicroBenchmarkController micro_benchmark_controller_;

 private:
  void InitializeProxy(scoped_ptr<Proxy> proxy);

  void PaintLayerContents(
      const RenderSurfaceLayerList& render_surface_layer_list,
      ResourceUpdateQueue* queue,
      bool* did_paint_content,
      bool* need_more_updates);
  void PaintMasksForRenderSurface(Layer* render_surface_layer,
                                  ResourceUpdateQueue* queue,
                                  bool* did_paint_content,
                                  bool* need_more_updates);
  bool UpdateLayers(Layer* root_layer, ResourceUpdateQueue* queue);
  void UpdateHudLayer();
  void TriggerPrepaint();

  void ReduceMemoryUsage();

  void PrioritizeTextures(
      const RenderSurfaceLayerList& render_surface_layer_list);
  void SetPrioritiesForSurfaces(size_t surface_memory_bytes);
  void SetPrioritiesForLayers(const RenderSurfaceLayerList& update_list);
  size_t CalculateMemoryForRenderSurfaces(
      const RenderSurfaceLayerList& update_list);

  bool AnimateLayersRecursive(Layer* current, base::TimeTicks time);

  struct UIResourceClientData {
    UIResourceClient* client;
    gfx::Size size;
  };

  typedef base::hash_map<UIResourceId, UIResourceClientData>
      UIResourceClientMap;
  UIResourceClientMap ui_resource_client_map_;
  int next_ui_resource_id_;

  typedef std::vector<UIResourceRequest> UIResourceRequestQueue;
  UIResourceRequestQueue ui_resource_request_queue_;

  void RecordGpuRasterizationHistogram();
  void CalculateLCDTextMetricsCallback(Layer* layer);

  void NotifySwapPromiseMonitorsOfSetNeedsCommit();

  bool inside_begin_main_frame_;
  bool needs_full_tree_sync_;

  base::CancelableClosure prepaint_callback_;

  LayerTreeHostClient* client_;
  scoped_ptr<Proxy> proxy_;

  int source_frame_number_;
  scoped_ptr<RenderingStatsInstrumentation> rendering_stats_instrumentation_;

  bool output_surface_lost_;

  scoped_refptr<Layer> root_layer_;
  scoped_refptr<HeadsUpDisplayLayer> hud_layer_;

  scoped_ptr<PrioritizedResourceManager> contents_texture_manager_;
  scoped_ptr<PrioritizedResource> surface_memory_placeholder_;

  base::WeakPtr<InputHandler> input_handler_weak_ptr_;
  base::WeakPtr<TopControlsManager> top_controls_manager_weak_ptr_;

  const LayerTreeSettings settings_;
  LayerTreeDebugState debug_state_;

  gfx::Size device_viewport_size_;
  bool top_controls_shrink_blink_size_;
  float top_controls_height_;
  float top_controls_shown_ratio_;
  float device_scale_factor_;

  bool visible_;

  base::OneShotTimer<LayerTreeHost> rate_limit_timer_;

  float page_scale_factor_;
  float min_page_scale_factor_;
  float max_page_scale_factor_;
  gfx::Vector2dF elastic_overscroll_;
  bool has_gpu_rasterization_trigger_;
  bool content_is_suitable_for_gpu_rasterization_;
  bool gpu_rasterization_histogram_recorded_;

  SkColor background_color_;
  bool has_transparent_background_;

  typedef ScopedPtrVector<PrioritizedResource> TextureList;
  size_t partial_texture_update_requests_;

  scoped_ptr<AnimationRegistrar> animation_registrar_;

  scoped_ptr<PendingPageScaleAnimation> pending_page_scale_animation_;

  // If set, then page scale animation has completed, but the client hasn't been
  // notified about it yet.
  bool did_complete_scale_animation_;

  bool in_paint_layer_contents_;

  static const int kTotalFramesToUseForLCDTextMetrics = 50;
  int total_frames_used_for_lcd_text_metrics_;

  struct LCDTextMetrics {
    LCDTextMetrics()
        : total_num_cc_layers(0),
          total_num_cc_layers_can_use_lcd_text(0),
          total_num_cc_layers_will_use_lcd_text(0) {}

    int64 total_num_cc_layers;
    int64 total_num_cc_layers_can_use_lcd_text;
    int64 total_num_cc_layers_will_use_lcd_text;
  };
  LCDTextMetrics lcd_text_metrics_;
  int id_;
  bool next_commit_forces_redraw_;

  scoped_refptr<Layer> overscroll_elasticity_layer_;
  scoped_refptr<Layer> page_scale_layer_;
  scoped_refptr<Layer> inner_viewport_scroll_layer_;
  scoped_refptr<Layer> outer_viewport_scroll_layer_;

  LayerSelectionBound selection_start_;
  LayerSelectionBound selection_end_;

  SharedBitmapManager* shared_bitmap_manager_;
  gpu::GpuMemoryBufferManager* gpu_memory_buffer_manager_;

  ScopedPtrVector<SwapPromise> swap_promise_list_;
  std::set<SwapPromiseMonitor*> swap_promise_monitor_;

  uint32_t surface_id_namespace_;
  uint32_t next_surface_sequence_;

  DISALLOW_COPY_AND_ASSIGN(LayerTreeHost);
};

}  // namespace cc

#endif  // CC_TREES_LAYER_TREE_HOST_H_