text: // Copyright 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.
  
  #ifndef UI_ACCESSIBILITY_AX_TREE_SOURCE_H_
  #define UI_ACCESSIBILITY_AX_TREE_SOURCE_H_
  
  #include "ui/accessibility/ax_node_data.h"
  
  namespace ui {
  
  // An AXTreeSource is an abstract interface for a serializable
  // accessibility tree. The tree may be in some other format or
  // may be computed dynamically, but maintains the properties that
  // it's a strict tree, it has a unique id for each node, and all
  // of the accessibility information about a node can be serialized
  // as an AXNodeData. This is the primary interface to use when
  // an accessibility tree will be sent over an IPC before being
  // consumed.
  template<class AXNodeSource>
  class AX_EXPORT AXTreeSource {
   public:
    virtual ~AXTreeSource() {}
    virtual AXNodeSource* GetRoot() const = 0;
    virtual AXNodeSource* GetFromId(int32 id) const = 0;
    virtual int32 GetId(const AXNodeSource* node) const = 0;
    virtual int GetChildCount(const AXNodeSource* node) const = 0;
    virtual AXNodeSource* GetChildAtIndex(const AXNodeSource* node, int index)
        const = 0;
    virtual AXNodeSource* GetParent(const AXNodeSource* node) const = 0;
  
    // Serialize one node in the tree.
    virtual void SerializeNode(
        const AXNodeSource* node, AXNodeData* out_data) const = 0;
  
   protected:
    AXTreeSource() {}
  };
  
  }  // namespace ui
  
  #endif  // UI_ACCESSIBILITY_AX_TREE_SOURCE_H_
  