layer_raster_cache_item.h

Go to the documentation of this file.

// Copyright 2013 The Flutter 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 FLUTTER_FLOW_LAYERS_LAYER_RASTER_CACHE_ITEM_H_
#define FLUTTER_FLOW_LAYERS_LAYER_RASTER_CACHE_ITEM_H_
 
#include <memory>
#include <optional>
 
#include "flutter/flow/raster_cache_item.h"
 
namespace flutter {
 
class LayerRasterCacheItem : public RasterCacheItem {
 public:
  explicit LayerRasterCacheItem(Layer* layer,
                                int layer_cached_threshold = 1,
                                bool can_cache_children = false);
 
  /**
   * @brief Create a LayerRasterCacheItem, connect a layer and manage the
   * Layer's raster cache
   *
   * @param layer_cache_threshold  after how many frames to start trying to
   * cache the layer self
   * @param can_cache_children the layer can do a cache for his children
   */
  static std::unique_ptr<LayerRasterCacheItem>
  Make(Layer*, int layer_cache_threshold, bool can_cache_children = false);
 
  std::optional<RasterCacheKeyID> GetId() const override;
 
  void PrerollSetup(PrerollContext* context, const SkMatrix& matrix) override;
 
  void PrerollFinalize(PrerollContext* context,
                       const SkMatrix& matrix) override;
 
  bool Draw(const PaintContext& context, const DlPaint* paint) const override;
 
  bool Draw(const PaintContext& context,
            DlCanvas* canvas,
            const DlPaint* paint) const override;
 
  bool TryToPrepareRasterCache(const PaintContext& context,
                               bool parent_cached = false) const override;
 
  void MarkCacheChildren() { can_cache_children_ = true; }
 
  void MarkNotCacheChildren() { can_cache_children_ = false; }
 
  bool IsCacheChildren() const { return cache_state_ == CacheState::kChildren; }
 
 protected:
  const SkRect* GetPaintBoundsFromLayer() const;
 
  Layer* layer_;
 
  // The id for cache the layer's children.
  std::optional<RasterCacheKeyID> layer_children_id_;
 
  int layer_cached_threshold_ = 1;
 
  // if the layer's children can be directly cache, set the param is true;
  bool can_cache_children_ = false;
 
  mutable int num_cache_attempts_ = 1;
};
 
}  // namespace flutter
 
#endif  // FLUTTER_FLOW_LAYERS_LAYER_RASTER_CACHE_ITEM_H_