cc/trees/layer_tree_host_common.h

   1 // Copyright 2011 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_TREES_LAYER_TREE_HOST_COMMON_H_
   6 #define CC_TREES_LAYER_TREE_HOST_COMMON_H_
   7
   8 #include <vector>
   9
  10 #include "base/memory/ref_counted.h"
  11 #include "cc/base/cc_export.h"
  12 #include "cc/base/scoped_ptr_vector.h"
  13 #include "cc/layers/layer_lists.h"
  14 #include "ui/gfx/rect.h"
  15 #include "ui/gfx/transform.h"
  16 #include "ui/gfx/vector2d.h"
  17
  18 namespace cc {
  19
  20 class LayerImpl;
  21 class Layer;
  22
  23 class CC_EXPORT LayerTreeHostCommon {
  24  public:
  25   static gfx::Rect CalculateVisibleRect(gfx::Rect target_surface_rect,
  26                                         gfx::Rect layer_bound_rect,
  27                                         const gfx::Transform& transform);
  28
  29   static void CalculateDrawProperties(
  30       Layer* root_layer,
  31       gfx::Size device_viewport_size,
  32       float device_scale_factor,
  33       float page_scale_factor,
  34       int max_texture_size,
  35       bool can_use_lcd_text,
  36       LayerList* render_surface_layer_list);
  37   static void CalculateDrawProperties(
  38       LayerImpl* root_layer,
  39       gfx::Size device_viewport_size,
  40       float device_scale_factor,
  41       float page_scale_factor,
  42       int max_texture_size,
  43       bool can_use_lcd_text,
  44       LayerImplList* render_surface_layer_list,
  45       bool update_tile_priorities);
  46
  47   // Performs hit testing for a given render_surface_layer_list.
  48   static LayerImpl* FindLayerThatIsHitByPoint(
  49       gfx::PointF screen_space_point,
  50       const LayerImplList& render_surface_layer_list);
  51
  52   static LayerImpl* FindLayerThatIsHitByPointInTouchHandlerRegion(
  53       gfx::PointF screen_space_point,
  54       const LayerImplList& render_surface_layer_list);
  55
  56   static bool LayerHasTouchEventHandlersAt(gfx::PointF screen_space_point,
  57                                            LayerImpl* layer_impl);
  58
  59   template <typename LayerType>
  60   static bool RenderSurfaceContributesToTarget(LayerType*,
  61                                                int target_surface_layer_id);
  62
  63   template <class Function, typename LayerType>
  64   static void CallFunctionForSubtree(LayerType* root_layer);
  65
  66   // Returns a layer with the given id if one exists in the subtree starting
  67   // from the given root layer (including mask and replica layers).
  68   template <typename LayerType>
  69   static LayerType* FindLayerInSubtree(LayerType* root_layer, int layer_id);
  70
  71   static Layer* get_child_as_raw_ptr(
  72       const LayerList& children,
  73       size_t index) {
  74     return children[index].get();
  75   }
  76
  77   static LayerImpl* get_child_as_raw_ptr(
  78       const OwnedLayerImplList& children,
  79       size_t index) {
  80     return children[index];
  81   }
  82
  83   struct ScrollUpdateInfo {
  84     int layer_id;
  85     gfx::Vector2d scroll_delta;
  86   };
  87 };
  88
  89 struct CC_EXPORT ScrollAndScaleSet {
  90   ScrollAndScaleSet();
  91   ~ScrollAndScaleSet();
  92
  93   std::vector<LayerTreeHostCommon::ScrollUpdateInfo> scrolls;
  94   float page_scale_delta;
  95 };
  96
  97 template <typename LayerType>
  98 bool LayerTreeHostCommon::RenderSurfaceContributesToTarget(
  99     LayerType* layer,
 100     int target_surface_layer_id) {
 101   // A layer will either contribute its own content, or its render surface's
 102   // content, to the target surface. The layer contributes its surface's content
 103   // when both the following are true:
 104   //  (1) The layer actually has a render surface, and
 105   //  (2) The layer's render surface is not the same as the target surface.
 106   //
 107   // Otherwise, the layer just contributes itself to the target surface.
 108
 109   return layer->render_surface() && layer->id() != target_surface_layer_id;
 110 }
 111
 112 template <typename LayerType>
 113 LayerType* LayerTreeHostCommon::FindLayerInSubtree(LayerType* root_layer,
 114                                                    int layer_id) {
 115   if (root_layer->id() == layer_id)
 116     return root_layer;
 117
 118   if (root_layer->mask_layer() && root_layer->mask_layer()->id() == layer_id)
 119     return root_layer->mask_layer();
 120
 121   if (root_layer->replica_layer() &&
 122       root_layer->replica_layer()->id() == layer_id)
 123     return root_layer->replica_layer();
 124
 125   for (size_t i = 0; i < root_layer->children().size(); ++i) {
 126     if (LayerType* found = FindLayerInSubtree(
 127             get_child_as_raw_ptr(root_layer->children(), i), layer_id))
 128       return found;
 129   }
 130   return NULL;
 131 }
 132
 133 template <class Function, typename LayerType>
 134 void LayerTreeHostCommon::CallFunctionForSubtree(LayerType* root_layer) {
 135   Function()(root_layer);
 136
 137   if (LayerType* mask_layer = root_layer->mask_layer())
 138     Function()(mask_layer);
 139   if (LayerType* replica_layer = root_layer->replica_layer()) {
 140     Function()(replica_layer);
 141     if (LayerType* mask_layer = replica_layer->mask_layer())
 142       Function()(mask_layer);
 143   }
 144
 145   for (size_t i = 0; i < root_layer->children().size(); ++i) {
 146     CallFunctionForSubtree<Function>(
 147         get_child_as_raw_ptr(root_layer->children(), i));
 148   }
 149 }
 150
 151 }  // namespace cc
 152
 153 #endif  // CC_TREES_LAYER_TREE_HOST_COMMON_H_