First Implementation of Snapped Points

cc/layers/layer.cc

 // Copyright 2010 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/layers/layer.h"
 
 #include <stddef.h>
 #include <stdint.h>
 
 #include <algorithm>
@@ skipping 292 matching lines @@
       node->bounds = inputs_.bounds;
     }
   }
 
   if (is_scroll_clip_layer_)
     layer_tree_host_->property_trees()->scroll_tree.set_needs_update(true);
 
   SetNeedsCommit();
 }
 
+void Layer::SetScrollSnapOffsets(const SnapPointList& offsets) {
+  DCHECK(IsPropertyChangeAllowed());
+  if (inputs_.snap_offsets == offsets)
+    return;
+  inputs_.snap_offsets = offsets;
+  SetPropertyTreesNeedRebuild();
+  SetNeedsCommit();
+}
+
 Layer* Layer::RootLayer() {
   Layer* layer = this;
   while (layer->parent())
     layer = layer->parent();
   return layer;
 }
 
 void Layer::RemoveAllChildren() {
   DCHECK(IsPropertyChangeAllowed());
   while (inputs_.children.size()) {
@@ skipping 867 matching lines @@
     layer->set_needs_show_scrollbars(true);
 
   // If the main thread commits multiple times before the impl thread actually
   // draws, then damage tracking will become incorrect if we simply clobber the
   // update_rect here. The LayerImpl's update_rect needs to accumulate (i.e.
   // union) any update changes that have occurred on the main thread.
   inputs_.update_rect.Union(layer->update_rect());
   layer->SetUpdateRect(inputs_.update_rect);
 
   layer->SetHasWillChangeTransformHint(has_will_change_transform_hint());
+  layer->SetScrollSnapOffsets(inputs_.snap_offsets);
+  /*for (SnapPoint point : inputs_.snap_offsets.horizontal) {
+    LOG(ERROR) << point.offset << " " << point.must_snap << " "
+      << point.is_start << " " << point.is_end;
+  }*/
   layer->SetNeedsPushProperties();
 
   // Reset any state that should be cleared for the next update.
   needs_show_scrollbars_ = false;
   subtree_property_changed_ = false;
   inputs_.update_rect = gfx::Rect();
 
   layer_tree_host_->RemoveLayerShouldPushProperties(this);
 }
 
@@ skipping 215 matching lines @@
       ->subtree_has_copy_request;
 }
 
 gfx::Transform Layer::ScreenSpaceTransform() const {
   DCHECK_NE(transform_tree_index_, TransformTree::kInvalidNodeId);
   return draw_property_utils::ScreenSpaceTransform(
       this, layer_tree_host_->property_trees()->transform_tree);
 }
 
 }  // namespace cc