1 // Copyright 2013 The Chromium Authors. All rights reserved. 2 // Use of this source code is governed by a BSD-style license that can be 3 // found in the LICENSE file. 4 5 #ifndef UI_ACCESSIBILITY_AX_TREE_SOURCE_H_ 6 #define UI_ACCESSIBILITY_AX_TREE_SOURCE_H_ 7 8 #include <vector> 9 10 #include "ui/accessibility/ax_node_data.h" 11 12 namespace ui { 13 14 // An AXTreeSource is an abstract interface for a serializable 15 // accessibility tree. The tree may be in some other format or 16 // may be computed dynamically, but maintains the properties that 17 // it's a strict tree, it has a unique id for each node, and all 18 // of the accessibility information about a node can be serialized 19 // as an AXNodeData. This is the primary interface to use when 20 // an accessibility tree will be sent over an IPC before being 21 // consumed. 22 template<typename AXNodeSource> 23 class AXTreeSource { 24 public: 25 virtual ~AXTreeSource() {} 26 27 // Get the root of the tree. 28 virtual AXNodeSource GetRoot() const = 0; 29 30 // Get a node by its id. If no node by that id exists in the tree, return a 31 // null node, i.e. one that will return false if you call IsValid on it. 32 virtual AXNodeSource GetFromId(int32 id) const = 0; 33 34 // Return the id of a node. All ids must be positive integers. 35 virtual int32 GetId(AXNodeSource node) const = 0; 36 37 // Append all children of |node| to |out_children|. 38 virtual void GetChildren(AXNodeSource node, 39 std::vector<AXNodeSource>* out_children) const = 0; 40 41 // Get the parent of |node|. 42 virtual AXNodeSource GetParent(AXNodeSource node) const = 0; 43 44 // Returns true if |node| is valid, and false if it's a null pointer or a 45 // node object representing the null pointer. 46 virtual bool IsValid(AXNodeSource node) const = 0; 47 48 // Returns true if two nodes are equal. 49 virtual bool IsEqual(AXNodeSource node1, 50 AXNodeSource node2) const = 0; 51 52 // Return a AXNodeSource representing null. 53 virtual AXNodeSource GetNull() const = 0; 54 55 // Serialize one node in the tree. 56 virtual void SerializeNode(AXNodeSource node, AXNodeData* out_data) const = 0; 57 58 protected: 59 AXTreeSource() {} 60 }; 61 62 } // namespace ui 63 64 #endif // UI_ACCESSIBILITY_AX_TREE_SOURCE_H_ 65
