Extend AXTreeSourceViews to handle aura::Window and views::Widget.

chrome/browser/ui/views/accessibility/ax_tree_source_views.cc

+// Copyright 2014 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 "chrome/browser/ui/views/accessibility/ax_tree_source_views.h"
+
+#include <vector>
+
+#include "ui/views/accessibility/ax_aura_obj_cache.h"
+#include "ui/views/accessibility/ax_aura_obj_wrapper.h"
+
+AXTreeSourceViews::AXTreeSourceViews() {
+  root_.reset(
+      new AXRootObjWrapper(views::AXAuraObjCache::GetInstance()->GetNextID()));
+}
+
+AXTreeSourceViews::~AXTreeSourceViews() {
+  root_.reset();
+}
+
+views::AXAuraObjWrapper* AXTreeSourceViews::GetRoot() const {

[aboxhall, 2014/04/28 19:50:38]

We could use a using-directive for views::AXAuraObjWrapper (and
views::AXAuraObjectCache) in this file, couldn't we? This would make at least
one function signature fit on one line.

[David Tseng, 2014/04/29 01:35:03]

Done.

+  return root_.get();
+}
+
+views::AXAuraObjWrapper* AXTreeSourceViews::GetFromId(int32 id) const {
+  if (id == root_->GetID())

[aboxhall, 2014/04/28 19:50:38]

Why special-case this? Is it not in the cache?

[David Tseng, 2014/04/29 01:35:03]

The root itself isn't stored in the AXAuraObjCache. The root isn't backed by an
Aura view for one and it only exists in the chrome/ layer (due to its dependency
on ash/shell.h).

+    return root_.get();
+  return views::AXAuraObjCache::GetInstance()->Get(id);
+}
+
+int32 AXTreeSourceViews::GetId(views::AXAuraObjWrapper* node) const {
+  return node->GetID();
+}
+
+void AXTreeSourceViews::GetChildren(views::AXAuraObjWrapper* node,
+    std::vector<views::AXAuraObjWrapper*>* out_children) const {
+  node->GetChildren(out_children);
+}
+
+views::AXAuraObjWrapper* AXTreeSourceViews::GetParent(
+    views::AXAuraObjWrapper* node) const {
+  views::AXAuraObjWrapper* parent = node->GetParent();
+  if (!parent && root_->HasChild(node))

[aboxhall, 2014/04/28 19:50:38]

Why would this happen? Does the root not get added as a parent?

[David Tseng, 2014/04/29 01:35:03]

There is no "root" hooking up all aura::Window objects. The root here only
exists for the purpose of rooting a tree containing Window's, View's, and
Widget's. If you call aura::Window::parent() on a root Window, it will return
NULL, so this covers that particular case.

+    parent = root_.get();
+  return parent;
+}
+
+bool AXTreeSourceViews::IsValid(views::AXAuraObjWrapper* node) const {
+  return node && node->GetID() != -1;
+}
+
+bool AXTreeSourceViews::IsEqual(views::AXAuraObjWrapper* node1,
+                                views::AXAuraObjWrapper* node2) const {
+  if (!node1 || !node2)

[aboxhall, 2014/04/28 19:50:38]

I assume we don't want to return true in the case where both nodes are null?

[David Tseng, 2014/04/29 01:35:03]

Yes, that's correct.

+    return false;
+
+  return node1->GetID() == node2->GetID() && node1->GetID() != -1;
+}
+
+views::AXAuraObjWrapper* AXTreeSourceViews::GetNull() const {
+  return NULL;
+}
+
+void AXTreeSourceViews::SerializeNode(
+    views::AXAuraObjWrapper* node, ui::AXNodeData* out_data) const {
+  node->Serialize(out_data);
+}
+
+std::string AXTreeSourceViews::ToString(
+    views::AXAuraObjWrapper* root, std::string prefix) {
+  ui::AXNodeData out_data;
+  root->Serialize(&out_data);

[aboxhall, 2014/04/28 19:50:38]

Similarly, why is this called out_data, when it never exists outside of this
scope?

[David Tseng, 2014/04/29 01:35:03]

Same as above.

+  std::string output = prefix + out_data.ToString() + '\n';
+
+  std::vector<views::AXAuraObjWrapper*> out_children;
+  root->GetChildren(&out_children);
+
+  prefix += prefix[0];
+  for (size_t i = 0; i < out_children.size(); ++i)
+    output += ToString(out_children[i], prefix);
+
+  return output;
+}