First Implementation of Snapped Points

third_party/WebKit/Source/core/layout/LayoutBox.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2005 Allan Sandfeld Jensen (kde@carewolf.com)
  *           (C) 2005, 2006 Samuel Weinig (sam.weinig@gmail.com)
  * Copyright (C) 2005, 2006, 2007, 2008, 2009, 2010 Apple Inc.
  *               All rights reserved.
  * Copyright (C) 2013 Adobe Systems Incorporated. All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
@@ skipping 433 matching lines @@
   SnapCoordinator* snap_coordinator = GetDocument().GetSnapCoordinator();
   if (!snap_coordinator)
     return;
 
   // Scroll snap type has no effect on the viewport defining element instead
   // they are handled by the LayoutView.
   bool allows_snap_container =
       GetNode() != GetDocument().ViewportDefiningElement();
 
   ScrollSnapType old_snap_type =
-      old_style ? old_style->GetScrollSnapType() : kScrollSnapTypeNone;
+      old_style ? old_style->GetScrollSnapType() : ScrollSnapType();
   ScrollSnapType new_snap_type = new_style && allows_snap_container
                                      ? new_style->GetScrollSnapType()
-                                     : kScrollSnapTypeNone;
+                                     : ScrollSnapType();
   if (old_snap_type != new_snap_type)
     snap_coordinator->SnapContainerDidChange(*this, new_snap_type);
 
-  Vector<LengthPoint> empty_vector;
+  /*Vector<LengthPoint> empty_vector;
   const Vector<LengthPoint>& old_snap_coordinate =
       old_style ? old_style->ScrollSnapCoordinate() : empty_vector;
   const Vector<LengthPoint>& new_snap_coordinate =
       new_style ? new_style->ScrollSnapCoordinate() : empty_vector;
   if (old_snap_coordinate != new_snap_coordinate)
-    snap_coordinator->SnapAreaDidChange(*this, new_snap_coordinate);
+    snap_coordinator->SnapAreaDidChange(*this, new_snap_coordinate);*/
+
+  ScrollSnapAlign old_snap_align =
+      old_style ? old_style->GetScrollSnapAlign() : ScrollSnapAlign();
+  ScrollSnapAlign new_snap_align = new_style && allows_snap_container
+                                       ? new_style->GetScrollSnapAlign()
+                                       : ScrollSnapAlign();
+  if (old_snap_align != new_snap_align)
+    snap_coordinator->SnapAreaDidChange(*this, new_snap_align);
 }
 
 void LayoutBox::AddScrollSnapMapping() {
   UpdateScrollSnapMappingAfterStyleChange(Style(), nullptr);
 }
 
 void LayoutBox::ClearScrollSnapMapping() {
   UpdateScrollSnapMappingAfterStyleChange(nullptr, Style());
 }
 
@@ skipping 5413 matching lines @@
 void LayoutBox::MutableForPainting::
     SavePreviousContentBoxSizeAndLayoutOverflowRect() {
   auto& rare_data = GetLayoutBox().EnsureRareData();
   rare_data.has_previous_content_box_size_and_layout_overflow_rect_ = true;
   rare_data.previous_content_box_size_ = GetLayoutBox().ContentBoxRect().Size();
   rare_data.previous_layout_overflow_rect_ =
       GetLayoutBox().LayoutOverflowRect();
 }
 
 }  // namespace blink