Initial support for native accessibility in ARC

chrome/browser/chromeos/arc/accessibility/ax_tree_source_arc.h

+// Copyright 2017 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.
+
+#ifndef CHROME_BROWSER_CHROMEOS_ARC_ACCESSIBILITY_AX_TREE_SOURCE_ARC_H_
+#define CHROME_BROWSER_CHROMEOS_ARC_ACCESSIBILITY_AX_TREE_SOURCE_ARC_H_
+
+#include "components/arc/common/accessibility_helper.mojom.h"
+#include "components/exo/wm_helper.h"
+#include "ui/accessibility/ax_node.h"
+#include "ui/accessibility/ax_node_data.h"
+#include "ui/accessibility/ax_tree_data.h"
+#include "ui/accessibility/ax_tree_serializer.h"
+#include "ui/accessibility/ax_tree_source.h"
+
+namespace arc {
+
+using AXTreeArcSerializer =
+    ui::AXTreeSerializer<mojom::AccessibilityNodeInfoData*,
+                         ui::AXNodeData,
+                         ui::AXTreeData>;
+
+// This class represents the accessibility tree from the focused ARC window.
+class AXTreeSourceArc
+    : public ui::AXTreeSource<mojom::AccessibilityNodeInfoData*,
+                              ui::AXNodeData,
+                              ui::AXTreeData>,
+      public exo::WMHelper::FocusObserver {
+ public:
+  AXTreeSourceArc();
+  ~AXTreeSourceArc() override;
+
+  // Notify automation of an accessibility event.
+  void NotifyAccessibilityEvent(mojom::AccessibilityEventData* event_data);
+
+ private:
+  // AXTreeSource overrides.
+  bool GetTreeData(ui::AXTreeData* data) const override;
+  mojom::AccessibilityNodeInfoData* GetRoot() const override;
+  mojom::AccessibilityNodeInfoData* GetFromId(int32_t id) const override;
+  int32_t GetId(mojom::AccessibilityNodeInfoData* node) const override;
+  void GetChildren(mojom::AccessibilityNodeInfoData* node,
+                   std::vector<mojom::AccessibilityNodeInfoData*>* out_children)
+      const override;
+  mojom::AccessibilityNodeInfoData* GetParent(
+      mojom::AccessibilityNodeInfoData* node) const override;
+  bool IsValid(mojom::AccessibilityNodeInfoData* node) const override;
+  bool IsEqual(mojom::AccessibilityNodeInfoData* node1,
+               mojom::AccessibilityNodeInfoData* node2) const override;
+  mojom::AccessibilityNodeInfoData* GetNull() const override;
+  void SerializeNode(mojom::AccessibilityNodeInfoData* node,
+                     ui::AXNodeData* out_data) const override;
+
+  // exo::WMHelper::FocusObserver overrides.
+  void OnWindowFocused(aura::Window* gained_focus,
+                       aura::Window* lost_focus) override;
+
+  // Resets tree state.
+  void Reset();
+
+  // The id of this tree.
+  int32_t id_;
+
+  // Maps an AccessibilityNodeInfo to its tree data.
+  std::map<int32_t, mojom::AccessibilityNodeInfoData*> tree_map_;
+  int32_t root_;
+  std::map<int32_t, int32_t> parent_map_;
+  std::unique_ptr<AXTreeArcSerializer> current_tree_serializer_;
+
+  DISALLOW_COPY_AND_ASSIGN(AXTreeSourceArc);
+};
+
+}  // namespace arc
+
+#endif  // CHROME_BROWSER_CHROMEOS_ARC_ACCESSIBILITY_AX_TREE_SOURCE_ARC_H_