a11y: Exclude children of nested keyboard accessible controls from a11y tree.

ui/views/accessibility/native_view_accessibility.cc

 // Copyright (c) 2013 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/accessibility/native_view_accessibility.h"
 
 #include "base/strings/utf_string_conversions.h"
 #include "ui/events/event_utils.h"
 #include "ui/gfx/native_widget_types.h"
 #include "ui/views/controls/native/native_view_host.h"
 #include "ui/views/view.h"
 #include "ui/views/widget/widget.h"
 
 namespace views {
 
+#if defined(OS_MACOSX)
+namespace {
+
+bool IsAccessibilityFocusableWhenEnabled(View* view) {
+  return view->focus_behavior() != View::FocusBehavior::NEVER &&
+         view->IsDrawn();
+}
+
+bool ViewHasFocusableAncestor(View* parent) {

[tapted, 2016/11/29 03:12:49]

nit: parent -> view (since it's not the parent that's passed in)

[Patti Lor, 2016/11/29 23:26:18]

Done.

+  while ((parent = parent->parent())) {
+    if (IsAccessibilityFocusableWhenEnabled(parent))
+      return true;
+  }
+  return false;
+}
+}

[tapted, 2016/11/29 03:12:49]

nit:  // namespace  (and and a blank line before, if clang-format lets you)

[Patti Lor, 2016/11/29 23:26:18]

Thanks - it seems to not let you if you've only got 1 method inside the anon
namespace, but two or more is fine.

+#endif
+
 #if !defined(PLATFORM_HAS_NATIVE_VIEW_ACCESSIBILITY_IMPL)
 // static
 NativeViewAccessibility* NativeViewAccessibility::Create(View* view) {
   return new NativeViewAccessibility(view);
 }
 #endif  // !defined(PLATFORM_HAS_NATIVE_VIEW_ACCESSIBILITY_IMPL)
 
 NativeViewAccessibility::NativeViewAccessibility(View* view)
     : view_(view),
       parent_widget_(nullptr),
@@ skipping 47 matching lines @@
   }
 
   view_->GetAccessibleNodeData(&data_);
   data_.location = gfx::RectF(view_->GetBoundsInScreen());
   base::string16 description;
   view_->GetTooltipText(gfx::Point(), &description);
   data_.AddStringAttribute(ui::AX_ATTR_DESCRIPTION,
                            base::UTF16ToUTF8(description));
 
   if (view_->IsAccessibilityFocusable())
-    data_.state |= (1 << ui::AX_STATE_FOCUSABLE);
+    data_.AddStateFlag(ui::AX_STATE_FOCUSABLE);
 
   if (!view_->enabled())
-    data_.state |= (1 << ui::AX_STATE_DISABLED);
+    data_.AddStateFlag(ui::AX_STATE_DISABLED);
 
   if (!view_->visible())
-    data_.state |= (1 << ui::AX_STATE_INVISIBLE);
+    data_.AddStateFlag(ui::AX_STATE_INVISIBLE);
+
+#if defined(OS_MACOSX)
+  // Make sure this element is ignored if there's a focusable parent. All
+  // keyboard focusable elements should be leaf nodes in the accessibility tree.
+  // Exceptions to this rule will themselves be accessibility focusable.
+  if (!IsAccessibilityFocusableWhenEnabled(view_) &&
+      ViewHasFocusableAncestor(view_))
+    data_.role = ui::AX_ROLE_UNKNOWN;
+#endif
 
   return data_;
 }
 
 int NativeViewAccessibility::GetChildCount() {
   int child_count = view_->child_count();
 
   std::vector<Widget*> child_widgets;
   PopulateChildWidgetVector(&child_widgets);
   child_count += child_widgets.size();
@@ skipping 33 matching lines @@
     return view_->GetWidget()->GetNativeView();
 #endif
 
   if (parent_widget_)
     return parent_widget_->GetRootView()->GetNativeViewAccessible();
 
   return nullptr;
 }
 
 gfx::Vector2d NativeViewAccessibility::GetGlobalCoordinateOffset() {
-  return gfx::Vector2d(0, 0);  // location is already in screen coordinates.
+  return gfx::Vector2d(0, 0);  // Location is already in screen coordinates.
 }
 
 gfx::NativeViewAccessible NativeViewAccessibility::HitTestSync(int x, int y) {
   if (!view_ || !view_->GetWidget())
     return nullptr;
 
   // Search child widgets first, since they're on top in the z-order.
   std::vector<Widget*> child_widgets;
   PopulateChildWidgetVector(&child_widgets);
   for (Widget* child_widget : child_widgets) {
     View* child_root_view = child_widget->GetRootView();
     gfx::Point point(x, y);
     View::ConvertPointFromScreen(child_root_view, &point);
     if (child_root_view->HitTestPoint(point))
       return child_root_view->GetNativeViewAccessible();
   }
 
   gfx::Point point(x, y);
   View::ConvertPointFromScreen(view_, &point);
   if (!view_->HitTestPoint(point))
     return nullptr;
 
-  // Check if the point is within any of the immediate children of this
-  // view. We don't have to search further because AXPlatformNode will
-  // do a recursive hit test if we return anything other than |this| or NULL.
+  // Check if the point is within any of the immediate children of this view. We
+  // don't have to search further because AXPlatformNodeWin will do a recursive
+  // hit test if we return anything other than GetNativeObject() or nullptr.
   for (int i = view_->child_count() - 1; i >= 0; --i) {
     View* child_view = view_->child_at(i);
     if (!child_view->visible())
       continue;
 
     gfx::Point point_in_child_coords(point);
     view_->ConvertPointToTarget(view_, child_view, &point_in_child_coords);
     if (child_view->HitTestPoint(point_in_child_coords))
       return child_view->GetNativeViewAccessible();
   }
@@ skipping 97 matching lines @@
               child_widget_platform_node->GetDelegate());
       if (child_widget_view_accessibility->parent_widget() != widget)
         child_widget_view_accessibility->SetParentWidget(widget);
     }
 
     result_child_widgets->push_back(child_widget);
   }
 }
 
 }  // namespace views