Re-land: Resurrect Aura Linux accessibility.

ui/views/accessibility/native_view_accessibility_auralinux.cc

+// Copyright 2015 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_auralinux.h"
+
+#include <algorithm>
+#include <vector>
+
+#include "base/memory/singleton.h"
+#include "ui/accessibility/ax_enums.h"
+#include "ui/accessibility/ax_node_data.h"
+#include "ui/accessibility/platform/ax_platform_node_auralinux.h"
+#include "ui/accessibility/platform/ax_platform_node_delegate.h"
+#include "ui/gfx/native_widget_types.h"
+#include "ui/views/views_delegate.h"
+#include "ui/views/widget/widget.h"
+#include "ui/views/widget/widget_observer.h"
+
+namespace views {
+
+namespace {
+
+// ATK requires that we have a single root "application" object that's the
+// owner of all other windows. This is a simple class that implements the
+// AXPlatformNodeDelegate interface so we can create such an application
+// object. Every time we create an accessibility object for a View, we add its
+// top-level widget to a vector so we can return the list of all top-level
+// windows as children of this application object.
+class AuraLinuxApplication
+    : public ui::AXPlatformNodeDelegate,
+      public WidgetObserver {
+ public:
+  // Get the single instance of this class.
+  static AuraLinuxApplication* GetInstance() {
+    return Singleton<AuraLinuxApplication>::get();
+  }
+
+  // Called every time we create a new accessibility on a View.
+  // Add the top-level widget to our registry so that we can enumerate all
+  // top-level widgets.
+  void RegisterWidget(Widget* widget) {
+    if (!widget)
+      return;
+
+    widget = widget->GetTopLevelWidget();
+    if (std::find(widgets_.begin(), widgets_.end(), widget) != widgets_.end())
+      return;
+
+    widgets_.push_back(widget);
+    widget->AddObserver(this);
+  }
+
+  gfx::NativeViewAccessible GetNativeViewAccessible() {
+    return platform_node_->GetNativeViewAccessible();
+  }
+
+  //
+  // WidgetObserver overrides.
+  //
+
+  void OnWidgetDestroying(Widget* widget) override {
+    auto iter = std::find(widgets_.begin(), widgets_.end(), widget);
+    if (iter != widgets_.end())
+      widgets_.erase(iter);
+  }
+
+  //
+  // ui::AXPlatformNodeDelegate overrides.
+  //
+
+  const ui::AXNodeData& GetData() override {
+    return data_;
+  }
+
+  gfx::NativeViewAccessible GetParent() override {
+    return nullptr;
+  }
+
+  int GetChildCount() override {
+    return static_cast<int>(widgets_.size());
+  }
+
+  gfx::NativeViewAccessible ChildAtIndex(int index) override {
+    if (index < 0 || index >= GetChildCount())
+      return nullptr;
+
+    Widget* widget = widgets_[index];
+    CHECK(widget);
+    return widget->GetRootView()->GetNativeViewAccessible();
+  }
+
+  gfx::Vector2d GetGlobalCoordinateOffset() override {
+    return gfx::Vector2d();
+  }
+
+  gfx::NativeViewAccessible HitTestSync(int x, int y) override {
+    return nullptr;
+  }
+
+  gfx::NativeViewAccessible GetFocus() override {
+    return nullptr;
+  }
+
+  gfx::AcceleratedWidget GetTargetForNativeAccessibilityEvent() override {
+    return gfx::kNullAcceleratedWidget;
+  }
+
+  void DoDefaultAction() override {
+  }
+
+  bool SetStringValue(const base::string16& new_value) override {
+    return false;
+  }
+
+ private:
+  friend struct DefaultSingletonTraits<AuraLinuxApplication>;
+
+  AuraLinuxApplication()
+      : platform_node_(ui::AXPlatformNode::Create(this)) {
+    data_.role = ui::AX_ROLE_APPLICATION;
+    if (ViewsDelegate::views_delegate) {
+      data_.AddStringAttribute(
+          ui::AX_ATTR_NAME,
+          ViewsDelegate::views_delegate->GetApplicationName());
+    }
+    ui::AXPlatformNodeAuraLinux::SetApplication(platform_node_);
+  }
+
+  ~AuraLinuxApplication() override {
+    platform_node_->Destroy();
+    platform_node_ = nullptr;
+  }
+
+  ui::AXPlatformNode* platform_node_;
+  ui::AXNodeData data_;
+  std::vector<Widget*> widgets_;
+
+  DISALLOW_COPY_AND_ASSIGN(AuraLinuxApplication);
+};
+
+}  // namespace
+
+// static
+NativeViewAccessibility* NativeViewAccessibility::Create(View* view) {
+  AuraLinuxApplication::GetInstance()->RegisterWidget(view->GetWidget());
+  return new NativeViewAccessibilityAuraLinux(view);
+}
+
+NativeViewAccessibilityAuraLinux::NativeViewAccessibilityAuraLinux(View* view)
+    : NativeViewAccessibility(view) {
+}
+
+NativeViewAccessibilityAuraLinux::~NativeViewAccessibilityAuraLinux() {
+}
+
+gfx::NativeViewAccessible NativeViewAccessibilityAuraLinux::GetParent() {
+  gfx::NativeViewAccessible parent = NativeViewAccessibility::GetParent();
+  if (!parent)
+    parent = AuraLinuxApplication::GetInstance()->GetNativeViewAccessible();
+  return parent;
+}
+
+}  // namespace views