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

ui/views/accessibility/native_view_accessibility_unittest.cc

 // Copyright 2014 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 "base/strings/utf_string_conversions.h"
 #include "ui/accessibility/ax_view_state.h"
 #include "ui/gfx/geometry/rect_conversions.h"
 #include "ui/views/accessibility/native_view_accessibility.h"
 #include "ui/views/controls/button/button.h"
 #include "ui/views/controls/label.h"
 #include "ui/views/test/views_test_base.h"
+#include "ui/views/widget/widget.h"
 
 namespace views {
 namespace test {
 
 class NativeViewAccessibilityTest;
 
 namespace {
 
 class TestButton : public Button {
  public:
   TestButton() : Button(NULL) {}
 };
 
+// Helper to add new View with specific bounds and focusability to a parent.
+View* AddNewChildWithBoundsAndFocusability(View& parent,
+                                           gfx::Rect bounds,
+                                           bool focusable) {
+  View* child = new View;
+  child->SetBounds(bounds.x(), bounds.y(), bounds.width(), bounds.height());
+  parent.AddChildView(child);
+  if (focusable)
+    child->SetFocusBehavior(ClientView::FocusBehavior::ACCESSIBLE_ONLY);
+  else
+    child->SetFocusBehavior(ClientView::FocusBehavior::NEVER);
+  return child;
+}
+
 }  // namespace
 
 class NativeViewAccessibilityTest : public ViewsTestBase {
  public:
   NativeViewAccessibilityTest() {}
   ~NativeViewAccessibilityTest() override {}
 
   void SetUp() override {
     ViewsTestBase::SetUp();
-
-    widget_ = new views::Widget;
-    views::Widget::InitParams params =
-        CreateParams(views::Widget::InitParams::TYPE_WINDOW_FRAMELESS);
-    params.bounds = gfx::Rect(0, 0, 200, 200);
+    widget_ = new Widget;
+    Widget::InitParams params = CreateParams(Widget::InitParams::TYPE_WINDOW);
+    params.bounds = gfx::Rect(200, 50);
     widget_->Init(params);
 
-    button_ = new TestButton();
-    button_->SetSize(gfx::Size(20, 20));
-    button_accessibility_ = NativeViewAccessibility::Create(button_);
+    button_ = new TestButton;
+    button_accessibility_ = button_->GetNativeViewAccessibility();
 
-    label_ = new Label();
+    label_ = new Label;
     button_->AddChildView(label_);
-    label_accessibility_ = NativeViewAccessibility::Create(label_);
+    label_accessibility_ = label_->GetNativeViewAccessibility();
 
-    widget_->SetContentsView(button_);
+    // Make sure both views start off as non-leaf accessibility elements.
+    button_->SetFocusBehavior(ClientView::FocusBehavior::ACCESSIBLE_ONLY);
+    label_->SetFocusBehavior(ClientView::FocusBehavior::ACCESSIBLE_ONLY);
+    button_->SetSize(gfx::Size(200, 50));
+    label_->SetSize(gfx::Size(200, 50));
+
+    widget_->GetContentsView()->AddChildView(button_);
+    widget_->Show();
   }
 
   void TearDown() override {
-    if (!widget_->IsClosed())
-      widget_->Close();
-    button_accessibility_->Destroy();
-    button_accessibility_ = NULL;
-    label_accessibility_->Destroy();
-    label_accessibility_ = NULL;
+    // Closing the Widget deletes child Views and their NativeViewAccessibility.
+    widget_->Close();
+    button_accessibility_ = nullptr;
+    label_accessibility_ = nullptr;
     ViewsTestBase::TearDown();
   }
 
  protected:
-  views::Widget* widget_;
+  Widget* widget_ = nullptr;
   TestButton* button_;
   NativeViewAccessibility* button_accessibility_;
   Label* label_;
   NativeViewAccessibility* label_accessibility_;
+
+  DISALLOW_COPY_AND_ASSIGN(NativeViewAccessibilityTest);
+};
+
+// Separate test class for a complicated test case for ignored accessibility
+// elements.
+class NativeViewAccessibilityIgnoredElementsTest : public ViewsTestBase {
+ public:
+  NativeViewAccessibilityIgnoredElementsTest() {}
+  ~NativeViewAccessibilityIgnoredElementsTest() override {}
+
+  void SetUp() override {
+    ViewsTestBase::SetUp();
+    // Set up an accessibility tree like so (X should be ignored). So a Views
+    // hierarchy as shown on the left should expose the accessibility tree in
+    // the middle, and respond to hit tests as shown on the right.
+    //
+    //           A                    A
+    //         /   \                / | \        +++---+---+---++---+---+---+++
+    //       B       X1            B  F  E       ||| C | F | B || F | A | E |||
+    //     / | \    / | \         / \            +++---+---+---++---+---+---+++
+    //    C  D X2  X3 X4 E       C   D
+    //    |        |
+    //   X5        F
+    //
+    // Note: For hit tests, the parent's bounds will be divided equally amongst
+    // its children (including ignored elements). This means all Views belonging
+    // on the same level of the Views hierarchy will be the same size.
+    a_ = new View;
+    a_->SetSize(gfx::Size(400, 20));
+    a_->SetFocusBehavior(ClientView::FocusBehavior::ACCESSIBLE_ONLY);
+
+    // Create Views in the left subtree from root |a_|.
+    gfx::Rect new_bounds(0, 0, a_->width() / 2, a_->height());
+    b_ = AddNewChildWithBoundsAndFocusability(*a_, new_bounds, true);
+    // |a_| has 6 leaves, so divvy up space equally between them for hit tests.
+    new_bounds = gfx::Rect(0, 0, a_->width() / 6, a_->height());
+    c_ = AddNewChildWithBoundsAndFocusability(*b_, new_bounds, true);
+    x5_ = AddNewChildWithBoundsAndFocusability(*c_, new_bounds, false);
+    // Update the |new_bounds| origin to position leaves next to each other.
+    new_bounds.set_x(new_bounds.x() + a_->width() / 6);
+    d_ = AddNewChildWithBoundsAndFocusability(*b_, new_bounds, true);
+    new_bounds.set_x(new_bounds.x() + a_->width() / 6);
+    x2_ = AddNewChildWithBoundsAndFocusability(*b_, new_bounds, false);
+    new_bounds.set_x(new_bounds.x() + a_->width() / 6);
+
+    // Create Views in the right subtree from root |a_|.
+    new_bounds.set_size(b_->size());
+    x1_ = AddNewChildWithBoundsAndFocusability(*a_, new_bounds, false);
+    new_bounds.set_origin(gfx::Point());
+    x3_ = AddNewChildWithBoundsAndFocusability(*x1_, new_bounds, false);
+    f_ = AddNewChildWithBoundsAndFocusability(*x3_, new_bounds, true);
+    new_bounds.set_x(new_bounds.x() + a_->width() / 6);
+    x4_ = AddNewChildWithBoundsAndFocusability(*x1_, new_bounds, false);
+    new_bounds.set_x(new_bounds.x() + a_->width() / 6);
+    e_ = AddNewChildWithBoundsAndFocusability(*x1_, new_bounds, true);
+
+    // Populate NativeViewAccessibility instances for convenience.
+    a_ax_ = a_->GetNativeViewAccessibility();
+    b_ax_ = b_->GetNativeViewAccessibility();
+    c_ax_ = c_->GetNativeViewAccessibility();
+    d_ax_ = d_->GetNativeViewAccessibility();
+    e_ax_ = e_->GetNativeViewAccessibility();
+    f_ax_ = f_->GetNativeViewAccessibility();
+    x1_ax_ = x1_->GetNativeViewAccessibility();
+    x2_ax_ = x2_->GetNativeViewAccessibility();
+    x3_ax_ = x3_->GetNativeViewAccessibility();
+    x4_ax_ = x4_->GetNativeViewAccessibility();
+    x5_ax_ = x5_->GetNativeViewAccessibility();
+
+    // Add everything to a new widget, needed for hit testing and parent tests.
+    widget_ = new Widget;
+    Widget::InitParams params = CreateParams(Widget::InitParams::TYPE_WINDOW);
+    widget_->Init(params);
+    widget_->GetContentsView()->AddChildView(a_);
+    widget_->Show();
+  }
+
+  void TearDown() override {
+    widget_->Close();
+    ViewsTestBase::TearDown();
+  }
+
+ protected:
+  // Don't use std::unique_ptr for the following Views - everything will be
+  // inside a widget, which will handle their deletion.
+  View* a_;
+  View* b_;
+  View* c_;
+  View* d_;
+  View* e_;
+  View* f_;
+  View* x1_;
+  View* x2_;
+  View* x3_;
+  View* x4_;
+  View* x5_;
+
+  // Destroyed when the View they are attached to is destroyed.
+  NativeViewAccessibility* a_ax_;
+  NativeViewAccessibility* b_ax_;
+  NativeViewAccessibility* c_ax_;
+  NativeViewAccessibility* d_ax_;
+  NativeViewAccessibility* e_ax_;
+  NativeViewAccessibility* f_ax_;
+  NativeViewAccessibility* x1_ax_;
+  NativeViewAccessibility* x2_ax_;
+  NativeViewAccessibility* x3_ax_;
+  NativeViewAccessibility* x4_ax_;
+  NativeViewAccessibility* x5_ax_;
+
+  Widget* widget_ = nullptr;
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(NativeViewAccessibilityIgnoredElementsTest);
 };
 
 TEST_F(NativeViewAccessibilityTest, RoleShouldMatch) {
   EXPECT_EQ(ui::AX_ROLE_BUTTON, button_accessibility_->GetData().role);
   EXPECT_EQ(ui::AX_ROLE_STATIC_TEXT, label_accessibility_->GetData().role);
 }
 
 TEST_F(NativeViewAccessibilityTest, BoundsShouldMatch) {
   gfx::Rect bounds = gfx::ToEnclosingRect(
       button_accessibility_->GetData().location);
   bounds.Offset(button_accessibility_->GetGlobalCoordinateOffset());
   EXPECT_EQ(button_->GetBoundsInScreen(), bounds);
 }
 
 TEST_F(NativeViewAccessibilityTest, LabelIsChildOfButton) {
   EXPECT_EQ(1, button_accessibility_->GetChildCount());
   EXPECT_EQ(label_->GetNativeViewAccessible(),
             button_accessibility_->ChildAtIndex(0));
   EXPECT_EQ(button_->GetNativeViewAccessible(),
             label_accessibility_->GetParent());
+
+  // Indicate the button should be a leaf node by ignoring the label.
+  label_->SetFocusBehavior(ClientView::FocusBehavior::NEVER);
+  EXPECT_EQ(button_, label_->parent());
+  EXPECT_EQ(0, button_accessibility_->GetChildCount());
+  EXPECT_EQ(nullptr, button_accessibility_->ChildAtIndex(0));
+
+  // Check this is still true even with a child inside the label.
+  View* label_child = AddNewChildWithBoundsAndFocusability(
+      *label_, label_->GetBoundsInScreen(), true);
+  EXPECT_EQ(1, button_accessibility_->GetChildCount());
+  EXPECT_EQ(label_child->GetNativeViewAccessible(),
+            button_accessibility_->ChildAtIndex(0));
+
+  label_child->SetFocusBehavior(ClientView::FocusBehavior::NEVER);
+  EXPECT_EQ(0, button_accessibility_->GetChildCount());
+  EXPECT_EQ(nullptr, button_accessibility_->ChildAtIndex(0));
+}
+
+TEST_F(NativeViewAccessibilityIgnoredElementsTest, GetChildCount) {
+  EXPECT_EQ(3, a_ax_->GetChildCount());
+  EXPECT_EQ(2, b_ax_->GetChildCount());
+  EXPECT_EQ(0, c_ax_->GetChildCount());
+  EXPECT_EQ(0, x5_ax_->GetChildCount());
+  EXPECT_EQ(0, d_ax_->GetChildCount());
+  EXPECT_EQ(0, x2_ax_->GetChildCount());
+  EXPECT_EQ(2, x1_ax_->GetChildCount());
+  EXPECT_EQ(1, x3_ax_->GetChildCount());
+  EXPECT_EQ(0, f_ax_->GetChildCount());
+  EXPECT_EQ(0, x4_ax_->GetChildCount());
+  EXPECT_EQ(0, e_ax_->GetChildCount());
+}
+
+TEST_F(NativeViewAccessibilityIgnoredElementsTest, ChildAtIndex) {
+  EXPECT_EQ(b_->GetNativeViewAccessible(), a_ax_->ChildAtIndex(0));
+  EXPECT_EQ(f_->GetNativeViewAccessible(), a_ax_->ChildAtIndex(1));
+  EXPECT_EQ(e_->GetNativeViewAccessible(), a_ax_->ChildAtIndex(2));
+  EXPECT_EQ(nullptr, a_ax_->ChildAtIndex(3));
+
+  EXPECT_EQ(c_->GetNativeViewAccessible(), b_ax_->ChildAtIndex(0));
+  EXPECT_EQ(d_->GetNativeViewAccessible(), b_ax_->ChildAtIndex(1));
+  EXPECT_EQ(nullptr, b_ax_->ChildAtIndex(2));
+
+  EXPECT_EQ(f_->GetNativeViewAccessible(), x1_ax_->ChildAtIndex(0));
+  EXPECT_EQ(e_->GetNativeViewAccessible(), x1_ax_->ChildAtIndex(1));
+  EXPECT_EQ(nullptr, x1_ax_->ChildAtIndex(2));
+
+  EXPECT_EQ(f_->GetNativeViewAccessible(), x3_ax_->ChildAtIndex(0));
+
+  // Node with ignored children.
+  EXPECT_EQ(nullptr, c_ax_->ChildAtIndex(0));
+  // Node with 0 children.
+  EXPECT_EQ(nullptr, d_ax_->ChildAtIndex(0));
+  // Ignored node with 0 children.
+  EXPECT_EQ(nullptr, x2_ax_->ChildAtIndex(0));
+}
+
+TEST_F(NativeViewAccessibilityIgnoredElementsTest, GetParent) {
+#if defined(OS_MACOSX)
+  // Only Mac is set up to return the native view going up to the Widget-level.
+  EXPECT_EQ(widget_->GetNativeView(), a_ax_->GetParent());
+#else
+  EXPECT_EQ(nullptr, a_ax_->GetParent());
+#endif
+  EXPECT_EQ(a_->GetNativeViewAccessible(), b_ax_->GetParent());
+  EXPECT_EQ(b_->GetNativeViewAccessible(), c_ax_->GetParent());
+  EXPECT_EQ(c_->GetNativeViewAccessible(), x5_ax_->GetParent());
+  EXPECT_EQ(b_->GetNativeViewAccessible(), d_ax_->GetParent());
+  EXPECT_EQ(b_->GetNativeViewAccessible(), x2_ax_->GetParent());
+
+  EXPECT_EQ(a_->GetNativeViewAccessible(), x1_ax_->GetParent());
+  EXPECT_EQ(a_->GetNativeViewAccessible(), x3_ax_->GetParent());
+  EXPECT_EQ(a_->GetNativeViewAccessible(), x4_ax_->GetParent());
+  EXPECT_EQ(a_->GetNativeViewAccessible(), e_ax_->GetParent());
+  EXPECT_EQ(a_->GetNativeViewAccessible(), f_ax_->GetParent());
+}
+
+TEST_F(NativeViewAccessibilityIgnoredElementsTest, IsLeafElement) {
+  EXPECT_FALSE(a_ax_->IsLeafElement());
+  EXPECT_FALSE(b_ax_->IsLeafElement());
+  EXPECT_TRUE(c_ax_->IsLeafElement());
+  EXPECT_TRUE(d_ax_->IsLeafElement());
+  EXPECT_TRUE(e_ax_->IsLeafElement());
+  EXPECT_TRUE(f_ax_->IsLeafElement());
+  EXPECT_FALSE(x1_ax_->IsLeafElement());
+  EXPECT_TRUE(x2_ax_->IsLeafElement());
+  EXPECT_FALSE(x3_ax_->IsLeafElement());
+  EXPECT_TRUE(x4_ax_->IsLeafElement());
+  EXPECT_TRUE(x5_ax_->IsLeafElement());
+}
+
+TEST_F(NativeViewAccessibilityIgnoredElementsTest, HitTestSync) {
+  // Move the hit point horizontally, incrementing by the leaf View width.
+  int min_width = a_->GetBoundsInScreen().width() / 6;
+  int curr_x = a_->GetBoundsInScreen().x() + min_width / 2;
+  const int y = a_->GetBoundsInScreen().CenterPoint().y();
+
+  // HitTestSync isn't recursive, so manually do the recursion until arriving at
+  // the correct answer. I.e., the last NativeViewAccessible being tested for
+  // each |curr_x|, |y| pair below would be the correct return value if
+  // HitTestSync were recursive.
+  EXPECT_EQ(b_->GetNativeViewAccessible(), a_ax_->HitTestSync(curr_x, y));
+  EXPECT_EQ(c_->GetNativeViewAccessible(), b_ax_->HitTestSync(curr_x, y));
+  EXPECT_EQ(c_->GetNativeViewAccessible(), c_ax_->HitTestSync(curr_x, y));
+  curr_x += min_width;
+  EXPECT_EQ(b_->GetNativeViewAccessible(), a_ax_->HitTestSync(curr_x, y));
+  EXPECT_EQ(d_->GetNativeViewAccessible(), b_ax_->HitTestSync(curr_x, y));
+  curr_x += min_width;
+  EXPECT_EQ(b_->GetNativeViewAccessible(), a_ax_->HitTestSync(curr_x, y));
+  EXPECT_EQ(x2_->GetNativeViewAccessible(), b_ax_->HitTestSync(curr_x, y));
+  EXPECT_EQ(b_->GetNativeViewAccessible(), x2_ax_->HitTestSync(curr_x, y));
+  curr_x += min_width;
+  EXPECT_EQ(x1_->GetNativeViewAccessible(), a_ax_->HitTestSync(curr_x, y));
+  EXPECT_EQ(x3_->GetNativeViewAccessible(), x1_ax_->HitTestSync(curr_x, y));
+  EXPECT_EQ(f_->GetNativeViewAccessible(), x3_ax_->HitTestSync(curr_x, y));
+  curr_x += min_width;
+  EXPECT_EQ(x1_->GetNativeViewAccessible(), a_ax_->HitTestSync(curr_x, y));
+  EXPECT_EQ(x4_->GetNativeViewAccessible(), x1_ax_->HitTestSync(curr_x, y));
+  EXPECT_EQ(a_->GetNativeViewAccessible(), x4_ax_->HitTestSync(curr_x, y));
+  curr_x += min_width;
+  EXPECT_EQ(x1_->GetNativeViewAccessible(), a_ax_->HitTestSync(curr_x, y));
+  EXPECT_EQ(e_->GetNativeViewAccessible(), x1_ax_->HitTestSync(curr_x, y));
+
+  // The Widget should be revealed if |e_| and |a_| are ignored.
+  a_->SetFocusBehavior(ClientView::FocusBehavior::NEVER);
+  e_->SetFocusBehavior(ClientView::FocusBehavior::NEVER);
+  EXPECT_EQ(x1_->GetNativeViewAccessible(), a_ax_->HitTestSync(curr_x, y));
+  EXPECT_EQ(e_->GetNativeViewAccessible(), x1_ax_->HitTestSync(curr_x, y));
+#if defined(OS_MACOSX)
+  EXPECT_EQ(widget_->GetNativeView(), e_ax_->HitTestSync(curr_x, y));
+#else
+  EXPECT_EQ(nullptr, e_ax_->HitTestSync(curr_x, y));
+#endif
 }
 
 // Subclass of NativeViewAccessibility that destroys itself when its
 // parent widget is destroyed, for the purposes of making sure this
 // doesn't lead to a crash.
 class TestNativeViewAccessibility : public NativeViewAccessibility {
  public:
   explicit TestNativeViewAccessibility(View* view)
       : NativeViewAccessibility(view) {}
 
@@ skipping 20 matching lines @@
   // WidgetObserver. Note that TestNativeViewAccessibility is a subclass
   // defined above that destroys itself when its parent widget is destroyed.
   TestNativeViewAccessibility* child_accessible =
       new TestNativeViewAccessibility(child_widget->GetRootView());
   child_accessible->SetParentWidget(parent_widget.get());
   parent_widget.reset();
 }
 
 }  // namespace test
 }  // namespace views