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// 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 <vector>
#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<typename AXNodeSource>
class AXTreeSource {
public:
virtual ~AXTreeSource() {}
// Get the root of the tree.
virtual AXNodeSource GetRoot() const = 0;
// Get a node by its id. If no node by that id exists in the tree, return a
// null node, i.e. one that will return false if you call IsValid on it.
virtual AXNodeSource GetFromId(int32 id) const = 0;
// Return the id of a node. All ids must be positive integers.
virtual int32 GetId(AXNodeSource node) const = 0;
// Append all children of |node| to |out_children|.
virtual void GetChildren(AXNodeSource node,
std::vector<AXNodeSource>* out_children) const = 0;
// Get the parent of |node|.
virtual AXNodeSource GetParent(AXNodeSource node) const = 0;
// Returns true if |node| is valid, and false if it's a null pointer or a
// node object representing the null pointer.
virtual bool IsValid(AXNodeSource node) const = 0;
// Returns true if two nodes are equal.
virtual bool IsEqual(AXNodeSource node1,
AXNodeSource node2) const = 0;
// Return a AXNodeSource representing null.
virtual AXNodeSource GetNull() const = 0;
// Serialize one node in the tree.
virtual void SerializeNode(AXNodeSource node, AXNodeData* out_data) const = 0;
protected:
AXTreeSource() {}
};
} // namespace ui
#endif // UI_ACCESSIBILITY_AX_TREE_SOURCE_H_