ui/accessibility/ax_serializable_tree.cc

   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 #include "ui/accessibility/ax_serializable_tree.h"
   6
   7 #include "ui/accessibility/ax_node.h"
   8
   9 namespace ui {
  10
  11 // This class is an implementation of the AXTreeSource interface with
  12 // AXNode as the node type, that just delegates to an AXTree. The purpose
  13 // of this is so that AXTreeSerializer only needs to work with the
  14 // AXTreeSource abstraction and doesn't need to actually know about
  15 // AXTree directly. Another AXTreeSource is used to abstract the Blink
  16 // accessibility tree.
  17 class AX_EXPORT AXTreeSourceAdapter : public AXTreeSource<const AXNode*> {
  18  public:
  19   AXTreeSourceAdapter(AXTree* tree) : tree_(tree) {}
  20   ~AXTreeSourceAdapter() override {}
  21
  22   // AXTreeSource implementation.
  23   AXNode* GetRoot() const override { return tree_->root(); }
  24
  25   AXNode* GetFromId(int32 id) const override { return tree_->GetFromId(id); }
  26
  27   int32 GetId(const AXNode* node) const override { return node->id(); }
  28
  29   void GetChildren(const AXNode* node,
  30                    std::vector<const AXNode*>* out_children) const override {
  31     for (int i = 0; i < node->child_count(); ++i)
  32       out_children->push_back(node->ChildAtIndex(i));
  33   }
  34
  35   AXNode* GetParent(const AXNode* node) const override {
  36     return node->parent();
  37   }
  38
  39   bool IsValid(const AXNode* node) const override { return node != NULL; }
  40
  41   bool IsEqual(const AXNode* node1, const AXNode* node2) const override {
  42     return node1 == node2;
  43   }
  44
  45   const AXNode* GetNull() const override { return NULL; }
  46
  47   void SerializeNode(const AXNode* node, AXNodeData* out_data) const override {
  48     *out_data = node->data();
  49   }
  50
  51  private:
  52   AXTree* tree_;
  53 };
  54
  55 AXSerializableTree::AXSerializableTree()
  56     : AXTree() {}
  57
  58 AXSerializableTree::AXSerializableTree(const AXTreeUpdate& initial_state)
  59     : AXTree(initial_state) {
  60 }
  61
  62 AXSerializableTree::~AXSerializableTree() {
  63 }
  64
  65 AXTreeSource<const AXNode*>* AXSerializableTree::CreateTreeSource() {
  66   return new AXTreeSourceAdapter(this);
  67 }
  68
  69 }  // namespace ui