ui/accessibility/ax_serializable_tree.cc

// 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.

#include "ui/accessibility/ax_serializable_tree.h"

#include "ui/accessibility/ax_node.h"

namespace ui {

// This class is an implementation of the AXTreeSource interface with
// AXNode as the node type, that just delegates to an AXTree. The purpose
// of this is so that AXTreeSerializer only needs to work with the
// AXTreeSource abstraction and doesn't need to actually know about
// AXTree directly. Another AXTreeSource is used to abstract the Blink
// accessibility tree.
class AX_EXPORT AXTreeSourceAdapter : public AXTreeSource<const AXNode*> {
 public:
  AXTreeSourceAdapter(AXTree* tree) : tree_(tree) {}
  ~AXTreeSourceAdapter() override {}

  // AXTreeSource implementation.
  AXNode* GetRoot() const override { return tree_->GetRoot(); }

  AXNode* GetFromId(int32 id) const override { return tree_->GetFromId(id); }

  int32 GetId(const AXNode* node) const override { return node->id(); }

  void GetChildren(const AXNode* node,
                   std::vector<const AXNode*>* out_children) const override {
    for (int i = 0; i < node->child_count(); ++i)
      out_children->push_back(node->ChildAtIndex(i));
  }

  AXNode* GetParent(const AXNode* node) const override {
    return node->parent();
  }

  bool IsValid(const AXNode* node) const override { return node != NULL; }

  bool IsEqual(const AXNode* node1, const AXNode* node2) const override {
    return node1 == node2;
  }

  const AXNode* GetNull() const override { return NULL; }

  void SerializeNode(const AXNode* node, AXNodeData* out_data) const override {
    *out_data = node->data();
  }

 private:
  AXTree* tree_;
};

AXSerializableTree::AXSerializableTree()
    : AXTree() {}

AXSerializableTree::AXSerializableTree(const AXTreeUpdate& initial_state)
    : AXTree(initial_state) {
}

AXSerializableTree::~AXSerializableTree() {
}

AXTreeSource<const AXNode*>* AXSerializableTree::CreateTreeSource() {
  return new AXTreeSourceAdapter(this);
}

}  // namespace ui