First step to move common accessibility code out of content.

content/common/ax_node_impl.h

+// Copyright (c) 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 CONTENT_COMMON_AX_NODE_IMPL_H_
+#define CONTENT_COMMON_AX_NODE_IMPL_H_
+
+#include "content/public/common/ax_node.h"
+#include "content/public/common/ax_node_data.h"
+
+namespace content {
+
+class AXTreeImpl;
+
+class CONTENT_EXPORT AXNodeImpl : public AXNode {
+ public:
+  AXNodeImpl();
+  virtual ~AXNodeImpl();
+
+  // AXNode.

[David Tseng, 2013/11/11 19:27:18]

nit: AXNode implementation.

[dmazzoni, 2013/11/12 00:03:04]

Done.

+  virtual int32 GetId() const OVERRIDE;
+  virtual AXNode* GetParent() const OVERRIDE;
+  virtual int GetChildCount() const OVERRIDE;
+  virtual AXNode* ChildAtIndex(int index) const OVERRIDE;
+  virtual const AXNodeData& data() const OVERRIDE;
+
+  const std::vector<AXNodeImpl*>& children() const { return children_; }
+
+  // Initialize the node. This sets up its place in the tree but does

[David Tseng, 2013/11/11 19:27:18]

A little confused. Does this mean this is initialization done before or after
children are available? Recall that some platforms (i.e. win) need to compute
some members based on fully initialized children.

[dmazzoni, 2013/11/12 00:03:04]

I haven't even added the hook to do platform-specific initialization after its
children are available.

I'll add interfaces like that in the next changelist when I refactor
BrowserAccessibility into AXPlatformNode and make it inherit from this.

+  // not set its data yet. After initialization, only index_in_parent
+  // is allowed to change, the others are guaranteed to never change.
+  virtual void Init(
+      AXTreeImpl* tree, AXNodeImpl* parent, int32 id, int32 index_in_parent);

[David Tseng, 2013/11/11 19:27:18]

I'm a little surprised to see this take an AXTreeImpl. Who keeps track of
parent/child links (the node or the tree class)?

[dmazzoni, 2013/11/12 00:03:04]

Good point. I got rid of the reference to the tree, making AXNode even simpler.

It's possible the platform node may want a pointer to the tree, but this base
class
doesn't need it.

+
+  // Set the node's accessibility data. This may be done during initial
+  // initialization or later when the node data changes.
+  virtual void SetData(const AXNodeData& src);
+
+  // Update the index in parent if siblings were inserted or deleted.
+  void UpdateIndexInParent(int index_in_parent);
+
+  // Detach all descendants of this subtree and push all of the node pointers,
+  // including this node, onto the end of |nodes|.
+  virtual void DetachTree(std::vector<AXNodeImpl*>* nodes);

[David Tseng, 2013/11/11 19:27:18]

out_nodes

[dmazzoni, 2013/11/12 00:03:04]

Done.

+
+  // Swap the internal children vector with |children|.

[David Tseng, 2013/11/11 19:27:18]

This instance takes ownership?

[dmazzoni, 2013/11/12 00:03:04]

Done.

+  virtual void SwapChildren(std::vector<AXNodeImpl*>& children);
+
+  // Marks this object for deletion, releases our reference to it,
+  // removes it from the tree, and recursively calls Destroy() on its
+  // children.  May not delete immediately due to reference counting.
+  //
+  // Reference counting is used on some platforms because the
+  // operating system may hold onto a reference to an AXNode
+  // object even after we're through with it.
+  virtual void Destroy();
+
+ private:
+  int index_in_parent_;
+  AXNodeImpl* parent_;
+  AXTreeImpl* tree_;
+  std::vector<AXNodeImpl*> children_;
+  AXNodeData data_;
+};
+
+
+}  // namespace content
+
+#endif  // CONTENT_COMMON_AX_NODE_IMPL_H_