Beginning of an accessibility implementation for html_viewer.

mojo/services/html_viewer/ax_provider_impl.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 "mojo/services/html_viewer/ax_provider_impl.h"
+
+#include "mojo/services/html_viewer/blink_basic_type_converters.h"
+#include "third_party/WebKit/public/platform/WebURL.h"
+#include "third_party/WebKit/public/web/WebAXObject.h"
+#include "third_party/WebKit/public/web/WebSettings.h"
+#include "third_party/WebKit/public/web/WebView.h"
+
+using blink::WebAXObject;
+using blink::WebURL;
+using blink::WebView;
+
+namespace mojo {
+
+AxProviderImpl::AxProviderImpl(WebView* web_view) : web_view_(web_view) {
+}
+
+void AxProviderImpl::GetTree(
+    const Callback<void(Array<AxNodePtr> nodes)>& callback) {
+  web_view_->settings()->setAccessibilityEnabled(true);
+  web_view_->settings()->setInlineTextBoxAccessibilityEnabled(true);
+
+  Array<AxNodePtr> result;
+  Populate(web_view_->accessibilityObject(), 0, 0, &result);
+  callback.Run(result.Pass());
+}
+
+int AxProviderImpl::Populate(const WebAXObject& ax_object,
+                             int parent_id,
+                             int next_sibling_id,
+                             Array<AxNodePtr>* result) {
+  AxNodePtr ax_node(ConvertAxNode(ax_object, parent_id, next_sibling_id));
+  int ax_node_id = ax_node->id;
+  if (ax_node.is_null())
+    return 0;
+
+  result->push_back(ax_node.Pass());
+
+  unsigned num_children = ax_object.childCount();
+  next_sibling_id = 0;
+  for (unsigned i = 0; i < num_children; ++i) {
+    int new_id = Populate(ax_object.childAt(num_children - i - 1),
+                          ax_node_id,
+                          next_sibling_id,
+                          result);
+    if (new_id != 0)
+      next_sibling_id = new_id;
+  }
+
+  return ax_node_id;
+}
+
+AxNodePtr AxProviderImpl::ConvertAxNode(const WebAXObject& ax_object,
+                                        int parent_id,
+                                        int next_sibling_id) {
+  AxNodePtr result;
+  if (!const_cast<WebAXObject&>(ax_object).updateLayoutAndCheckValidity())
+    return result.Pass();
+
+  result = AxNode::New();
+  result->id = static_cast<int>(ax_object.axID());
+  result->parent_id = parent_id;
+  result->next_sibling_id = next_sibling_id;
+  result->bounds = Rect::From(ax_object.boundingBoxRect());
+
+  if (ax_object.isAnchor()) {
+    result->link = AxLink::New();
+    result->link->url = String::From(ax_object.url().string());
+  } else if (ax_object.childCount() == 0 &&
+             !ax_object.stringValue().isEmpty()) {
+    result->text = AxText::New();
+    result->text->content = String::From(ax_object.stringValue());
+  }
+
+  return result.Pass();
+}
+
+}  // namespace mojo