Replace layer id with Element id for tracking scrollbar animation controllers

cc/trees/layer_tree_host_impl.cc

 // 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.
 
 #include "cc/trees/layer_tree_host_impl.h"
 
 #include <stddef.h>
 #include <stdint.h>
 
 #include <algorithm>
@@ skipping 188 matching lines @@
       need_update_gpu_rasterization_status_(false),
       content_is_suitable_for_gpu_rasterization_(true),
       has_gpu_rasterization_trigger_(false),
       use_gpu_rasterization_(false),
       use_msaa_(false),
       gpu_rasterization_status_(GpuRasterizationStatus::OFF_DEVICE),
       input_handler_client_(NULL),
       did_lock_scrolling_layer_(false),
       wheel_scrolling_(false),
       scroll_affects_scroll_handler_(false),
-      scroll_layer_id_mouse_currently_over_(Layer::INVALID_ID),
-      scroll_layer_id_mouse_currently_captured_(Layer::INVALID_ID),
       tile_priorities_dirty_(false),
       settings_(settings),
       visible_(false),
       cached_managed_memory_policy_(settings.gpu_memory_policy),
       is_synchronous_single_threaded_(!task_runner_provider->HasImplThread() &&
                                       !settings.single_thread_proxy_scheduler),
       // Must be initialized after is_synchronous_single_threaded_ and
       // task_runner_provider_.
       tile_manager_(this,
                     GetTaskRunner(),
@@ skipping 2727 matching lines @@
     base::TimeDelta delayed_by) {
   InputHandler::ScrollStatus scroll_status;
   scroll_status.main_thread_scrolling_reasons =
       MainThreadScrollingReason::kNotScrollingOnMain;
   ScrollTree& scroll_tree = active_tree_->property_trees()->scroll_tree;
   ScrollNode* scroll_node = scroll_tree.CurrentlyScrollingNode();
 
   if (scroll_node) {
     // Flash the overlay scrollbar even if the scroll dalta is 0.
     ScrollbarAnimationController* animation_controller =
-        ScrollbarAnimationControllerForId(scroll_node->owning_layer_id);
+        ScrollbarAnimationControllerForId(scroll_node->element_id);
 
     if (animation_controller)
       animation_controller->WillUpdateScroll();
 
     gfx::Vector2dF delta = scroll_delta;
     if (!scroll_node->user_scrollable_horizontal)
       delta.set_x(0);
     if (!scroll_node->user_scrollable_vertical)
       delta.set_y(0);
 
@@ skipping 30 matching lines @@
           scroll_node->id != scroll_animating_latched_node_id_) {
         continue;
       }
 
       bool scrolls_main_viewport_scroll_layer =
           viewport()->MainScrollLayer() &&
           viewport()->MainScrollLayer()->scroll_tree_index() == scroll_node->id;
       if (scrolls_main_viewport_scroll_layer) {
         // Flash the overlay scrollbar even if the scroll dalta is 0.
         ScrollbarAnimationController* animation_controller =
-            ScrollbarAnimationControllerForId(scroll_node->owning_layer_id);
+            ScrollbarAnimationControllerForId(scroll_node->element_id);
 
         if (animation_controller)
           animation_controller->WillUpdateScroll();
 
         gfx::Vector2dF scrolled =
             viewport()->ScrollAnimated(pending_delta, delayed_by);
         // Viewport::ScrollAnimated returns pending_delta as long as it starts
         // an animation.
         if (scrolled == pending_delta) {
           scroll_animating_latched_node_id_ = scroll_node->id;
@@ skipping 239 matching lines @@
   DCHECK(scroll_state);
 
   TRACE_EVENT0("cc", "LayerTreeHostImpl::ScrollBy");
   ScrollTree& scroll_tree = active_tree_->property_trees()->scroll_tree;
   ScrollNode* scroll_node = scroll_tree.CurrentlyScrollingNode();
 
   if (!scroll_node)
     return InputHandlerScrollResult();
 
   ScrollbarAnimationController* animation_controller =
-      ScrollbarAnimationControllerForId(scroll_node->owning_layer_id);
+      ScrollbarAnimationControllerForId(scroll_node->element_id);
 
   if (animation_controller)
     animation_controller->WillUpdateScroll();
 
   float initial_top_controls_offset =
       browser_controls_offset_manager_->ControlsTopOffset();
 
   scroll_state->set_delta_consumed_for_scroll_sequence(
       did_lock_scrolling_layer_);
   scroll_state->set_is_direct_manipulation(!wheel_scrolling_);
@@ skipping 119 matching lines @@
 
   gfx::RectF device_viewport_layer_impl_bounds = MathUtil::MapClippedRect(
       layer_impl->ScreenSpaceTransform(), gfx::RectF(layer_impl_bounds));
 
   return device_viewport_layer_impl_bounds.ManhattanDistanceToPoint(
       device_viewport_point);
 }
 
 void LayerTreeHostImpl::MouseDown() {
   ScrollbarAnimationController* animation_controller =
-      ScrollbarAnimationControllerForId(scroll_layer_id_mouse_currently_over_);
+      ScrollbarAnimationControllerForId(
+          scroll_element_id_mouse_currently_over_);
   if (animation_controller) {
     animation_controller->DidMouseDown();
-    scroll_layer_id_mouse_currently_captured_ =
-        scroll_layer_id_mouse_currently_over_;
+    scroll_element_id_mouse_currently_captured_ =
+        scroll_element_id_mouse_currently_over_;
   }
 }
 
 void LayerTreeHostImpl::MouseUp() {
-  if (scroll_layer_id_mouse_currently_captured_ != Layer::INVALID_ID) {
+  if (scroll_element_id_mouse_currently_captured_) {
     ScrollbarAnimationController* animation_controller =
         ScrollbarAnimationControllerForId(
-            scroll_layer_id_mouse_currently_captured_);
+            scroll_element_id_mouse_currently_captured_);
 
-    scroll_layer_id_mouse_currently_captured_ = Layer::INVALID_ID;
+    scroll_element_id_mouse_currently_captured_ = ElementId();
 
     if (animation_controller)
       animation_controller->DidMouseUp();
   }
 }
 
 void LayerTreeHostImpl::MouseMoveAt(const gfx::Point& viewport_point) {
   gfx::PointF device_viewport_point = gfx::ScalePoint(
       gfx::PointF(viewport_point), active_tree_->device_scale_factor());
   LayerImpl* layer_impl =
       active_tree_->FindLayerThatIsHitByPoint(device_viewport_point);
 
   // Check if mouse is over a scrollbar or not.
   // TODO(sahel): get rid of this extera checking when
   // FindScrollLayerForDeviceViewportPoint finds the proper layer for
   // scrolling on main thread when mouse is over scrollbar as well.
-  int new_id = Layer::INVALID_ID;
+  ElementId new_element_id;
   if (layer_impl && layer_impl->ToScrollbarLayer())
-    new_id = layer_impl->ToScrollbarLayer()->ScrollLayerId();
-  if (new_id == Layer::INVALID_ID) {
+    new_element_id = layer_impl->ToScrollbarLayer()->ScrollElementId();
+  if (!new_element_id) {
     bool scroll_on_main_thread = false;
     uint32_t main_thread_scrolling_reasons;
     LayerImpl* scroll_layer_impl = FindScrollLayerForDeviceViewportPoint(
         device_viewport_point, InputHandler::TOUCHSCREEN, layer_impl,
         &scroll_on_main_thread, &main_thread_scrolling_reasons);
 
     // Scrollbars for the viewport are registered with the outer viewport layer.
     if (scroll_layer_impl == InnerViewportScrollLayer())
       scroll_layer_impl = OuterViewportScrollLayer();
 
-    new_id = scroll_layer_impl ? scroll_layer_impl->id() : Layer::INVALID_ID;
+    if (scroll_layer_impl)
+      new_element_id = scroll_layer_impl->element_id();
   }
 
-  if (new_id != scroll_layer_id_mouse_currently_over_) {
+  if (new_element_id != scroll_element_id_mouse_currently_over_) {
     ScrollbarAnimationController* old_animation_controller =
         ScrollbarAnimationControllerForId(
-            scroll_layer_id_mouse_currently_over_);
+            scroll_element_id_mouse_currently_over_);
     if (old_animation_controller) {
       old_animation_controller->DidMouseLeave();
     }
-    scroll_layer_id_mouse_currently_over_ = new_id;
+    scroll_element_id_mouse_currently_over_ = new_element_id;
   }
 
   ScrollbarAnimationController* new_animation_controller =
-      ScrollbarAnimationControllerForId(new_id);
+      ScrollbarAnimationControllerForId(new_element_id);
   if (!new_animation_controller)
     return;
 
-  for (ScrollbarLayerImplBase* scrollbar : ScrollbarsFor(new_id)) {
+  int new_layer_id = active_tree_->LayerIdByElementId(new_element_id);
+  for (ScrollbarLayerImplBase* scrollbar :
+       active_tree_->ScrollbarsFor(new_layer_id)) {
     new_animation_controller->DidMouseMoveNear(
         scrollbar->orientation(),
         DeviceSpaceDistanceToLayer(device_viewport_point, scrollbar) /
             active_tree_->device_scale_factor());
   }
 }
 
 void LayerTreeHostImpl::MouseLeave() {
   for (auto& pair : scrollbar_animation_controllers_)
     pair.second->DidMouseLeave();
-  scroll_layer_id_mouse_currently_over_ = Layer::INVALID_ID;
+  scroll_element_id_mouse_currently_over_ = ElementId();
 }
 
 void LayerTreeHostImpl::PinchGestureBegin() {
   pinch_gesture_active_ = true;
   client_->RenewTreePriority();
   pinch_gesture_end_should_clear_scrolling_node_ = !CurrentlyScrollingNode();
 
   active_tree_->SetCurrentlyScrollingNode(OuterViewportScrollNode());
   browser_controls_offset_manager_->PinchBegin();
 }
@@ skipping 48 matching lines @@
       tree_impl->InnerViewportScrollLayer()
           ? tree_impl->InnerViewportScrollLayer()->id()
           : Layer::INVALID_ID;
 
   tree_impl->property_trees()->scroll_tree.CollectScrollDeltas(
       scroll_info, inner_viewport_layer_id);
 }
 
 static void CollectScrollbarUpdates(
     ScrollAndScaleSet* scroll_info,
-    std::unordered_map<int, std::unique_ptr<ScrollbarAnimationController>>*
-        controllers) {
+    std::unordered_map<ElementId,
+                       std::unique_ptr<ScrollbarAnimationController>,
+                       ElementIdHash>* controllers) {
   scroll_info->scrollbars.reserve(controllers->size());
   for (auto& pair : *controllers) {
     scroll_info->scrollbars.push_back(LayerTreeHostCommon::ScrollbarsUpdateInfo(
         pair.first, pair.second->ScrollbarsHidden()));
   }
 }
 
 std::unique_ptr<ScrollAndScaleSet> LayerTreeHostImpl::ProcessScrollDeltas() {
   std::unique_ptr<ScrollAndScaleSet> scroll_info(new ScrollAndScaleSet());
 
@@ skipping 123 matching lines @@
   if (active_tree_->root_layer_for_testing()) {
     std::unique_ptr<base::Value> json(
         active_tree_->root_layer_for_testing()->LayerTreeAsJson());
     base::JSONWriter::WriteWithOptions(
         *json, base::JSONWriter::OPTIONS_PRETTY_PRINT, &str);
   }
   return str;
 }
 
 void LayerTreeHostImpl::RegisterScrollbarAnimationController(
-    int scroll_layer_id) {
+    int scroll_layer_id,
+    ElementId scroll_element_id) {
   if (settings().scrollbar_animator == LayerTreeSettings::NO_ANIMATOR)
     return;
-  if (ScrollbarAnimationControllerForId(scroll_layer_id))
+  if (ScrollbarAnimationControllerForId(scroll_element_id))
     return;
-  scrollbar_animation_controllers_[scroll_layer_id] =
+  scrollbar_animation_controllers_[scroll_element_id] =
       active_tree_->CreateScrollbarAnimationController(scroll_layer_id);
 }
 
 void LayerTreeHostImpl::UnregisterScrollbarAnimationController(
-    int scroll_layer_id) {
-  scrollbar_animation_controllers_.erase(scroll_layer_id);
+    ElementId scroll_element_id) {
+  scrollbar_animation_controllers_.erase(scroll_element_id);
 }
 
 ScrollbarAnimationController*
 LayerTreeHostImpl::ScrollbarAnimationControllerForId(
-    int scroll_layer_id) const {
+    ElementId scroll_element_id) const {
   // The viewport layers have only one set of scrollbars and their controller
   // is registered with the outer viewport.
   if (InnerViewportScrollLayer() && OuterViewportScrollLayer() &&
-      scroll_layer_id == InnerViewportScrollLayer()->id())
-    scroll_layer_id = OuterViewportScrollLayer()->id();
-  auto i = scrollbar_animation_controllers_.find(scroll_layer_id);
+      scroll_element_id == InnerViewportScrollLayer()->element_id())
+    scroll_element_id = OuterViewportScrollLayer()->element_id();
+  auto i = scrollbar_animation_controllers_.find(scroll_element_id);
   if (i == scrollbar_animation_controllers_.end())
     return nullptr;
   return i->second.get();
 }
 
 void LayerTreeHostImpl::PostDelayedScrollbarAnimationTask(
     const base::Closure& task,
     base::TimeDelta delay) {
   client_->PostDelayedAnimationTaskOnImplThread(task, delay);
 }
@@ skipping 568 matching lines @@
 }
 
 void LayerTreeHostImpl::UpdateScrollSourceInfo(bool is_wheel_scroll) {
   if (is_wheel_scroll)
     has_scrolled_by_wheel_ = true;
   else
     has_scrolled_by_touch_ = true;
 }
 
 }  // namespace cc