views: add focus ring to TreeView

ui/views/controls/tree/tree_view.cc

Index: ui/views/controls/tree/tree_view.cc
diff --git a/ui/views/controls/tree/tree_view.cc b/ui/views/controls/tree/tree_view.cc
index a87875e7870ddb7af5c099fcd3f9a917d7d549a1..e6b97a9abe4c69c92897ef12866b6ea3b646dfda 100644
--- a/ui/views/controls/tree/tree_view.cc
+++ b/ui/views/controls/tree/tree_view.cc
@@ -11,6 +11,7 @@
 #include "base/message_loop/message_loop.h"
 #include "ui/accessibility/ax_view_state.h"
 #include "ui/base/ime/input_method.h"
+#include "ui/base/material_design/material_design_controller.h"
 #include "ui/base/resource/resource_bundle.h"
 #include "ui/events/event.h"
 #include "ui/events/keycodes/keyboard_codes.h"
@@ -21,6 +22,7 @@
 #include "ui/gfx/skia_util.h"
 #include "ui/native_theme/native_theme.h"
 #include "ui/resources/grit/ui_resources.h"
+#include "ui/views/controls/focus_ring.h"
 #include "ui/views/controls/prefix_selector.h"
 #include "ui/views/controls/scroll_view.h"
 #include "ui/views/controls/textfield/textfield.h"
@@ -631,6 +633,13 @@ void TreeView::OnFocus() {
   // Notify the InputMethod so that it knows to query the TextInputClient.
   if (GetInputMethod())
     GetInputMethod()->OnCaretBoundsChanged(GetPrefixSelector());
+
+  if (ui::MaterialDesignController::IsSecondaryUiMaterial() &&
+      PlatformStyle::kTreeViewHasFocusRing) {
+    View* focus_ring_view = FindFocusRingView();
+    FocusRing::Install(focus_ring_view);
+    focus_ring_view->SchedulePaint();
+  }
 }
 
 void TreeView::OnBlur() {
@@ -639,6 +648,12 @@ void TreeView::OnBlur() {
   SchedulePaintForNode(selected_node_);
   if (selector_)
     selector_->OnViewBlur();
+  if (ui::MaterialDesignController::IsSecondaryUiMaterial() &&
+      PlatformStyle::kTreeViewHasFocusRing) {
+    View* focus_ring_view = FindFocusRingView();
+    FocusRing::Uninstall(focus_ring_view);
+    focus_ring_view->SchedulePaint();
+  }
 }
 
 bool TreeView::OnClickOrTap(const ui::LocatedEvent& event) {
@@ -1057,6 +1072,20 @@ bool TreeView::IsPointInExpandControl(InternalNode* node,
   return arrow_bounds.Contains(point);
 }
 
+View* TreeView::FindFocusRingView() {
+  // If this View is the grandchild of a ScrollView, use the grandparent
+  // ScrollView for the focus ring instead of this View so that the focus ring
+  // won't be scrolled. Otherwise, fall back to using this View. Since
+  // ScrollViews have a single content view, which they wrap in a
+  // ScrollView::Viewport, being the grandchild of a ScrollView implies being
+  // the sole grandchild, which means it's fine to wrap the focus ring around
+  // the grandparent here.
+  View* grandparent = parent() ? parent()->parent() : nullptr;
+  if (grandparent && grandparent->GetClassName() == ScrollView::kViewClassName)
+    return grandparent;
+  return this;
+}
+
 // InternalNode ----------------------------------------------------------------
 
 TreeView::InternalNode::InternalNode()