[ash-md] Adds support for Z-order iteration in views::View

ui/views/view.cc

Index: ui/views/view.cc
diff --git a/ui/views/view.cc b/ui/views/view.cc
index 92223157d4c8671aaa2c55aab4c006d1ee25b265..b1f3125281e1723fd40c341c7b9b70c1d3030b18 100644
--- a/ui/views/view.cc
+++ b/ui/views/view.cc
@@ -461,6 +461,10 @@ void View::OnEnabledChanged() {
   SchedulePaint();
 }
 
+View::Views View::GetChildrenOrderedByVisualOrder() {
+  return children_;
+}
+
 // Transformations -------------------------------------------------------------
 
 gfx::Transform View::GetTransform() const {
@@ -917,8 +921,10 @@ View* View::GetTooltipHandlerForPoint(const gfx::Point& point) {
 
   // Walk the child Views recursively looking for the View that most
   // tightly encloses the specified point.
-  for (int i = child_count() - 1; i >= 0; --i) {
-    View* child = child_at(i);
+  View::Views children = GetChildrenOrderedByVisualOrder();
+  DCHECK_EQ(child_count(), static_cast<int>(children.size()));
+  for (int i = children.size() - 1; i >= 0; --i) {
+    View* child = children[i];
     if (!child->visible())
       continue;
 
@@ -1437,9 +1443,13 @@ void View::NativeViewHierarchyChanged() {
 
 void View::PaintChildren(const ui::PaintContext& context) {
   TRACE_EVENT1("views", "View::PaintChildren", "class", GetClassName());
-  for (int i = 0, count = child_count(); i < count; ++i)
-    if (!child_at(i)->layer())
-      child_at(i)->Paint(context);
+  View::Views children = GetChildrenOrderedByVisualOrder();
+  DCHECK_EQ(child_count(), static_cast<int>(children.size()));
+  for (int i = 0, count = children.size(); i < count; ++i) {

[sky, 2016/12/13 23:40:56]

Use range based for-loop?

[varkha, 2016/12/19 20:35:44]

Done. I will try to get the rest of the similar iterations in view.cc and
view_targeter_delegate.cc to be like this as well (in a separate CL).

[varkha, 2016/12/19 20:56:15]

Posted https://codereview.chromium.org/2583343003 for the rest of the similar
iterations in this file.

+    View* child = children[i];
+    if (!child->layer())
+      child->Paint(context);
+  }
 }
 
 void View::OnPaint(gfx::Canvas* canvas) {
@@ -1588,10 +1598,10 @@ void View::ReorderChildLayers(ui::Layer* parent_layer) {
     // Iterate backwards through the children so that a child with a layer
     // which is further to the back is stacked above one which is further to
     // the front.
-    for (Views::reverse_iterator it(children_.rbegin());
-         it != children_.rend(); ++it) {
-      (*it)->ReorderChildLayers(parent_layer);
-    }
+    View::Views children = GetChildrenOrderedByVisualOrder();
+    DCHECK_EQ(child_count(), static_cast<int>(children.size()));
+    for (int i = children.size() - 1; i >= 0; --i)

[sky, 2016/12/13 23:40:56]

I think a reverse iterator is safer here.

[varkha, 2016/12/19 20:35:44]

Done.

+      children[i]->ReorderChildLayers(parent_layer);
   }
 }