One accessibility tree per frame.

content/browser/frame_host/render_frame_host_impl.cc

 // Copyright 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.
 
 #include "content/browser/frame_host/render_frame_host_impl.h"
 
 #include <utility>
 
 #include "base/bind.h"
 #include "base/containers/hash_tables.h"
@@ skipping 1612 matching lines @@
     std::vector<AXEventNotificationDetails> details;
     details.reserve(params.size());
     for (size_t i = 0; i < params.size(); ++i) {
       const AccessibilityHostMsg_EventParams& param = params[i];
       AXEventNotificationDetails detail;
       detail.event_type = param.event_type;
       detail.id = param.id;
       detail.ax_tree_id = GetAXTreeID();
       if (param.update.has_tree_data) {
         detail.update.has_tree_data = true;
-        AXContentTreeDataToAXTreeData(param.update.tree_data,
-                                      &detail.update.tree_data);
+        ax_content_tree_data_ = param.update.tree_data;
+        AXContentTreeDataToAXTreeData(&detail.update.tree_data);
       }
       detail.update.node_id_to_clear = param.update.node_id_to_clear;
       detail.update.nodes.resize(param.update.nodes.size());
       for (size_t i = 0; i < param.update.nodes.size(); ++i) {
         AXContentNodeDataToAXNodeData(param.update.nodes[i],
                                       &detail.update.nodes[i]);
       }
       details.push_back(detail);
     }
 
@@ skipping 72 matching lines @@
     const AXContentTreeUpdate& snapshot) {
   const auto& it = ax_tree_snapshot_callbacks_.find(callback_id);
   if (it != ax_tree_snapshot_callbacks_.end()) {
     ui::AXTreeUpdate dst_snapshot;
     dst_snapshot.nodes.resize(snapshot.nodes.size());
     for (size_t i = 0; i < snapshot.nodes.size(); ++i) {
       AXContentNodeDataToAXNodeData(snapshot.nodes[i],
                                     &dst_snapshot.nodes[i]);
     }
     if (snapshot.has_tree_data) {
-      AXContentTreeDataToAXTreeData(snapshot.tree_data,
-                                    &dst_snapshot.tree_data);
+      ax_content_tree_data_ = snapshot.tree_data;
+      AXContentTreeDataToAXTreeData(&dst_snapshot.tree_data);
       dst_snapshot.has_tree_data = true;
     }
     it->second.Run(dst_snapshot);
     ax_tree_snapshot_callbacks_.erase(it);
   } else {
     NOTREACHED() << "Received AX tree snapshot response for unknown id";
   }
 }
 
 void RenderFrameHostImpl::OnToggleFullscreen(bool enter_fullscreen) {
@@ skipping 597 matching lines @@
   int callback_id = next_id++;
   Send(new AccessibilityMsg_SnapshotTree(routing_id_, callback_id));
   ax_tree_snapshot_callbacks_.insert(std::make_pair(callback_id, callback));
 }
 
 void RenderFrameHostImpl::SetAccessibilityCallbackForTesting(
     const base::Callback<void(ui::AXEvent, int)>& callback) {
   accessibility_testing_callback_ = callback;
 }
 
+void RenderFrameHostImpl::UpdateAXTreeData() {
+  AccessibilityMode accessibility_mode = delegate_->GetAccessibilityMode();
+  if (accessibility_mode == AccessibilityModeOff ||
+      !RenderFrameHostImpl::IsRFHStateActive(rfh_state())) {
+    return;
+  }
+
+  std::vector<AXEventNotificationDetails> details;
+  details.reserve(1U);
+  AXEventNotificationDetails detail;
+  detail.ax_tree_id = GetAXTreeID();
+  detail.update.has_tree_data = true;
+  AXContentTreeDataToAXTreeData(&detail.update.tree_data);
+  details.push_back(detail);
+
+  if (browser_accessibility_manager_)
+    browser_accessibility_manager_->OnAccessibilityEvents(details);
+
+  delegate_->AccessibilityEventReceived(details);
+}
+
 void RenderFrameHostImpl::SetTextTrackSettings(
     const FrameMsg_TextTrackSettings_Params& params) {
   DCHECK(!GetParent());
   Send(new FrameMsg_SetTextTrackSettings(routing_id_, params));
 }
 
 const ui::AXTree* RenderFrameHostImpl::GetAXTreeForTesting() {
   return ax_tree_for_testing_.get();
 }
 
@@ skipping 262 matching lines @@
             BrowserPluginInstanceIDToAXTreeID(value)));
         break;
       case AX_CONTENT_INT_ATTRIBUTE_LAST:
         NOTREACHED();
         break;
     }
   }
 }
 
 void RenderFrameHostImpl::AXContentTreeDataToAXTreeData(
-    const AXContentTreeData& src,
     ui::AXTreeData* dst) {
+  const AXContentTreeData& src = ax_content_tree_data_;
+
   // Copy the common fields.
   *dst = src;
 
   if (src.routing_id != -1)
     dst->tree_id = RoutingIDToAXTreeID(src.routing_id);
 
   if (src.parent_routing_id != -1)
     dst->parent_tree_id = RoutingIDToAXTreeID(src.parent_routing_id);
+
+  // If this is not the root frame tree node, we're done.
+  if (frame_tree_node()->parent())
+    return;
+
+  // For the root frame tree node, also store the AXTreeID of the focused frame.
+  FrameTreeNode* focused_frame_tree_node = frame_tree_->GetFocusedFrame();
+  if (!focused_frame_tree_node)
+    return;
+  RenderFrameHostImpl* focused_frame =
+      focused_frame_tree_node->current_frame_host();
+  if (!focused_frame)

[nasko, 2016/03/09 22:44:37]

Is this even possible? I think we can't have a frame, which can be focused,
which doesn't have any document associated with it.

[dmazzoni, 2016/03/09 22:55:28]

Good call. I'll change it to DCHECK.

+    return;
+  dst->focused_tree_id = focused_frame->GetAXTreeID();
 }
 
 }  // namespace content