views: add focus ring to TreeView

ui/views/controls/scroll_view.cc

 // Copyright (c) 2012 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 "ui/views/controls/scroll_view.h"
 
 #include "base/feature_list.h"
 #include "base/logging.h"
 #include "base/macros.h"
 #include "ui/events/event.h"
 #include "ui/gfx/canvas.h"
 #include "ui/native_theme/native_theme.h"
 #include "ui/views/background.h"
 #include "ui/views/border.h"
+#include "ui/views/controls/focus_ring.h"
 #include "ui/views/style/platform_style.h"
 #include "ui/views/widget/widget.h"
 
 namespace views {
 
 const char ScrollView::kViewClassName[] = "ScrollView";
 
 namespace {
 
 const base::Feature kToolkitViewsScrollWithLayers {
@@ skipping 262 matching lines @@
   if (!is_bounded())
     return View::GetHeightForWidth(width);
 
   gfx::Insets insets = GetInsets();
   width = std::max(0, width - insets.width());
   int height = contents()->GetHeightForWidth(width) + insets.height();
   return std::min(std::max(height, min_height_), max_height_);
 }
 
 void ScrollView::Layout() {
+  // If there's a focus ring, lay it out first.
+  for (int i = 0; i < child_count(); ++i)

[sky, 2016/10/12 20:08:53]

I suspect tree isn't the only place that wants scrollview to have a focusring.
How about adding explicit functions to ScrollView for install/uninstall the
focusring and then Scrollview can cache the focus_ring_ and call Layout on it?
That matches what we do in Textfield.

[Elly Fong-Jones, 2016/10/12 21:10:22]

Done.

+    if (child_at(i)->GetClassName() == FocusRing::kViewClassName)
+      child_at(i)->Layout();
+
   gfx::Rect available_rect = GetContentsBounds();
   if (is_bounded()) {
     int content_width = available_rect.width();
     int content_height = contents()->GetHeightForWidth(content_width);
     if (content_height > height()) {
       content_width = std::max(content_width - GetScrollBarWidth(), 0);
       content_height = contents()->GetHeightForWidth(content_width);
     }
     if (contents()->bounds().size() != gfx::Size(content_width, content_height))
       contents()->SetBounds(0, 0, content_width, content_height);
@@ skipping 459 matching lines @@
 
 VariableRowHeightScrollHelper::RowInfo
     FixedRowHeightScrollHelper::GetRowInfo(int y) {
   if (y < top_margin_)
     return RowInfo(0, top_margin_);
   return RowInfo((y - top_margin_) / row_height_ * row_height_ + top_margin_,
                  row_height_);
 }
 
 }  // namespace views