Keep track of accessibility focus across windows.

third_party/WebKit/Source/modules/accessibility/AXObjectCacheImpl.cpp

 /*
  * Copyright (C) 2014, Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  *
  * 1.  Redistributions of source code must retain the above copyright
  *     notice, this list of conditions and the following disclaimer.
  * 2.  Redistributions in binary form must reproduce the above copyright
@@ skipping 131 matching lines @@
         if (!child->isImageMapLink())
             continue;
 
         if (toAXImageMapLink(child)->areaElement() == areaElement)
             return child;
     }
 
     return 0;
 }
 
-AXObject* AXObjectCacheImpl::focusedUIElementForPage(const Page* page)
+AXObject* AXObjectCacheImpl::focusedObject()
 {
-    if (!page->settings().accessibilityEnabled())
+    if (!accessibilityEnabled())
         return 0;
 
-    // Cross-process accessibility is not yet implemented.
+    // We don't have to return anything if the focused frame is not local;
+    // the remote frame will have its own AXObjectCacheImpl and the focused
+    // object will be sorted out by the browser process.
+    Page* page = m_document->page();
     if (!page->focusController().focusedOrMainFrame()->isLocalFrame())

[dcheng, 2016/02/13 02:29:31]

Why focusedOrMainFrame()? Is it because we have to pick something even if no
frame is focused?

[dmazzoni, 2016/02/16 18:54:54]

Ah, looks like we can just call focusedFrame() - that will either return a
LocalFrame or nullptr if it's remote, which is what we want. If the focused
frame is remote we want to return null so the AXObjectCache for that remote
frame can handle it.

Looking at the TODO in the source of FocusController::focusedFrame(), do you
think it'd be helpful to add a synonym like focusedFrameIfLocal() or
focusedFrameOrNullIfRemote() so that it's clear that this is OOPIF-aware? Up to
you.

         return 0;
 
-    // get the focused node in the page
+    // Get the focused node in the page.
     Document* focusedDocument = toLocalFrame(page->focusController().focusedOrMainFrame())->document();
     Node* focusedNode = focusedDocument->focusedElement();
     if (!focusedNode)
         focusedNode = focusedDocument;
 
-    if (isHTMLAreaElement(*focusedNode))
+    // If it's an image map, get the focused link within the image map.
+    if (isHTMLAreaElement(focusedNode))
         return focusedImageMapUIElement(toHTMLAreaElement(focusedNode));
 
+    // See if there's a page popup, for example a calendar picker.
+    Element* adjustedFocusedElement = focusedDocument->adjustedFocusedElement();
+    if (isHTMLInputElement(adjustedFocusedElement)) {
+        if (AXObject* axPopup = toHTMLInputElement(adjustedFocusedElement)->popupRootAXObject()) {
+            if (Element* focusedElementInPopup = axPopup->document()->focusedElement())
+                focusedNode = focusedElementInPopup;
+        }
+
+    }
+
     AXObject* obj = getOrCreate(focusedNode);
     if (!obj)
         return 0;
 
     if (obj->shouldFocusActiveDescendant()) {
         if (AXObject* descendant = obj->activeDescendant())
             obj = descendant;
     }
 
     // the HTML element, for example, is focusable but has an AX object that is ignored
@@ skipping 933 matching lines @@
 
 void AXObjectCacheImpl::handleFocusedUIElementChanged(Node* oldFocusedNode, Node* newFocusedNode)
 {
     if (!newFocusedNode)
         return;
 
     Page* page = newFocusedNode->document().page();
     if (!page)
         return;
 
-    AXObject* focusedObject = focusedUIElementForPage(page);
+    AXObject* focusedObject = this->focusedObject();
     if (!focusedObject)
         return;
 
     AXObject* oldFocusedObject = get(oldFocusedNode);
 
     postPlatformNotification(oldFocusedObject, AXBlur);
     postPlatformNotification(focusedObject, AXFocusedUIElementChanged);
 }
 
 void AXObjectCacheImpl::handleInitialFocus()
@@ skipping 114 matching lines @@
     visitor->trace(m_nodeObjectMapping);
 #endif
 
     visitor->trace(m_objects);
     visitor->trace(m_notificationsToPost);
 
     AXObjectCache::trace(visitor);
 }
 
 } // namespace blink