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..f4d1007afbba0f41134d3cf8a44b85eb5de87f06 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) {
+    ScrollView* focus_ring_view = FindFocusRingView();
+    focus_ring_view->SetHasFocusRing(true);
+    focus_ring_view->SchedulePaint();

[sky, 2016/10/12 23:58:01]

Are you sure you need a SchedulePaint here? If so, I think it should be in
ScrollView.

[Elly Fong-Jones, 2016/10/13 11:14:56]

I believe so - FocusRing::Install() and FocusRing::Uninstall() do it, anyway. I
moved it to ScrollView.

+  }
 }
 
 void TreeView::OnBlur() {
@@ -639,6 +648,12 @@ void TreeView::OnBlur() {
   SchedulePaintForNode(selected_node_);
   if (selector_)
     selector_->OnViewBlur();
+  if (ui::MaterialDesignController::IsSecondaryUiMaterial() &&

[sky, 2016/10/12 23:58:01]

As this is nearly the same as the above and only differs in the parameter to
SetHasFocusRing, how about a function like SetShowFocusRing(bool)?

[Elly Fong-Jones, 2016/10/13 11:14:56]

Done.

+      PlatformStyle::kTreeViewHasFocusRing) {
+    ScrollView* focus_ring_view = FindFocusRingView();
+    focus_ring_view->SetHasFocusRing(false);
+    focus_ring_view->SchedulePaint();
+  }
 }
 
 bool TreeView::OnClickOrTap(const ui::LocatedEvent& event) {
@@ -1057,6 +1072,19 @@ bool TreeView::IsPointInExpandControl(InternalNode* node,
   return arrow_bounds.Contains(point);
 }
 
+ScrollView* 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. 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 static_cast<ScrollView*>(grandparent);
+  return nullptr;
+}
+
 // InternalNode ----------------------------------------------------------------
 
 TreeView::InternalNode::InternalNode()