Keep track of accessibility focus across windows.

chrome/renderer/extensions/automation_internal_custom_bindings.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/renderer/extensions/automation_internal_custom_bindings.h"
 
 #include <stddef.h>
 #include <stdint.h>
 
 #include "base/bind.h"
@@ skipping 398 matching lines @@
                 base::Bind(&AutomationInternalCustomBindings::FN, \
                 base::Unretained(this)))
   ROUTE_FUNCTION(IsInteractPermitted);
   ROUTE_FUNCTION(GetSchemaAdditions);
   ROUTE_FUNCTION(GetRoutingID);
   ROUTE_FUNCTION(StartCachingAccessibilityTrees);
   ROUTE_FUNCTION(DestroyAccessibilityTree);
   ROUTE_FUNCTION(AddTreeChangeObserver);
   ROUTE_FUNCTION(RemoveTreeChangeObserver);
   ROUTE_FUNCTION(GetChildIDAtIndex);
+  ROUTE_FUNCTION(GetFocus);
   #undef ROUTE_FUNCTION
 
   // Bindings that take a Tree ID and return a property of the tree.
 
   RouteTreeIDFunction(
       "GetRootID", [](v8::Isolate* isolate, v8::ReturnValue<v8::Value> result,
                       TreeCache* cache) {
         result.Set(v8::Integer::New(isolate, cache->tree.root()->id()));
       });
   RouteTreeIDFunction(
@@ skipping 341 matching lines @@
        iter != tree_change_observers_.end(); ++iter) {
     if (iter->id == observer_id) {
       tree_change_observers_.erase(iter);
       break;
     }
   }
 
   UpdateOverallTreeChangeObserverFilter();
 }
 
+void AutomationInternalCustomBindings::GetFocus(
+    const v8::FunctionCallbackInfo<v8::Value>& args) {
+  if (args.Length() != 1 || !args[0]->IsNumber()) {
+    ThrowInvalidArgumentsException(this);
+    return;
+  }
+
+  int tree_id = args[0]->Int32Value();
+  ui::AXNode* focus = nullptr;
+  TreeCache* cache = GetTreeCacheFromTreeID(tree_id);
+  if (!cache)
+    return;
+
+  int focus_id = cache->tree.data().focus_id;
+  focus = cache->tree.GetFromId(focus_id);
+  if (!focus)
+    return;
+
+  while (focus->data().HasIntAttribute(ui::AX_ATTR_CHILD_TREE_ID)) {
+    // Try to keep following focus recursively, by letting |tree_id| be the
+    // new subtree to search in, while keeping |focus_tree_id| set to the tree
+    // where we know we found a focused node.
+    int child_tree_id =
+        focus->data().GetIntAttribute(ui::AX_ATTR_CHILD_TREE_ID);
+
+    TreeCache* child_cache = GetTreeCacheFromTreeID(child_tree_id);
+    if (!child_cache)
+      break;
+
+    int child_focus_id = child_cache->tree.data().focus_id;
+    ui::AXNode* child_focus = cache->tree.GetFromId(focus_id);
+    if (!child_focus)
+      break;
+
+    focus = child_focus;
+    tree_id = child_tree_id;
+    focus_id = child_focus_id;
+  }
+
+  v8::Isolate* isolate = GetIsolate();
+  v8::Local<v8::Object> result(v8::Object::New(isolate));
+  result->Set(CreateV8String(isolate, "treeId"),
+              v8::Integer::New(isolate, tree_id));
+  result->Set(CreateV8String(isolate, "nodeId"),
+              v8::Integer::New(isolate, focus_id));
+  args.GetReturnValue().Set(result);
+}
+
 void AutomationInternalCustomBindings::UpdateOverallTreeChangeObserverFilter() {
   tree_change_observer_overall_filter_ =
       api::automation::TREE_CHANGE_OBSERVER_FILTER_NOTREECHANGES;
   for (const auto& observer : tree_change_observers_) {
     tree_change_observer_overall_filter_ =
         std::max(observer.filter, tree_change_observer_overall_filter_);
   }
 }
 
 void AutomationInternalCustomBindings::RouteTreeIDFunction(
@@ skipping 264 matching lines @@
   v8::Local<v8::Array> args(v8::Array::New(GetIsolate(), 2U));
   args->Set(0U, v8::Integer::New(GetIsolate(), tree_id));
   v8::Local<v8::Array> nodes(v8::Array::New(GetIsolate(), ids.size()));
   args->Set(1U, nodes);
   for (size_t i = 0; i < ids.size(); ++i)
     nodes->Set(i, v8::Integer::New(GetIsolate(), ids[i]));
   context()->DispatchEvent("automationInternal.onNodesRemoved", args);
 }
 
 }  // namespace extensions