One AXObjectCache per frame

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 50 matching lines @@
 #include "modules/accessibility/AXLayoutObject.h"
 #include "modules/accessibility/AXList.h"
 #include "modules/accessibility/AXListBox.h"
 #include "modules/accessibility/AXListBoxOption.h"
 #include "modules/accessibility/AXMediaControls.h"
 #include "modules/accessibility/AXMenuList.h"
 #include "modules/accessibility/AXMenuListOption.h"
 #include "modules/accessibility/AXMenuListPopup.h"
 #include "modules/accessibility/AXProgressIndicator.h"
 #include "modules/accessibility/AXSVGRoot.h"
-#include "modules/accessibility/AXScrollView.h"
-#include "modules/accessibility/AXScrollbar.h"
 #include "modules/accessibility/AXSlider.h"
 #include "modules/accessibility/AXSpinButton.h"
 #include "modules/accessibility/AXTable.h"
 #include "modules/accessibility/AXTableCell.h"
 #include "modules/accessibility/AXTableColumn.h"
 #include "modules/accessibility/AXTableHeaderContainer.h"
 #include "modules/accessibility/AXTableRow.h"
 #include "wtf/PassRefPtr.h"
 
 namespace blink {
@@ skipping 63 matching lines @@
         if (!child->isImageMapLink())
             continue;
 
         if (toAXImageMapLink(child)->areaElement() == areaElement)
             return child;
     }
 
     return 0;
 }
 
-AXObject* AXObjectCacheImpl::focusedUIElementForPage(const Page* page)
-{
-    if (!page->settings().accessibilityEnabled())
-        return 0;
-
-    // Cross-process accessibility is not yet implemented.
-    if (!page->focusController().focusedOrMainFrame()->isLocalFrame())
-        return 0;
-
-    // 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))
-        return focusedImageMapUIElement(toHTMLAreaElement(focusedNode));
-
-    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
-    if (obj->accessibilityIsIgnored())
-        obj = obj->parentObjectUnignored();
-
-    return obj;
-}
-
-AXObject* AXObjectCacheImpl::get(Widget* widget)
-{
-    if (!widget)
-        return 0;
-
-    AXID axID = m_widgetObjectMapping.get(widget);
-    ASSERT(!HashTraits<AXID>::isDeletedValue(axID));
-    if (!axID)
-        return 0;
-
-    return m_objects.get(axID);
-}
-
 AXObject* AXObjectCacheImpl::get(LayoutObject* layoutObject)
 {
     if (!layoutObject)
         return 0;
 
     AXID axID = m_layoutObjectMapping.get(layoutObject);
     ASSERT(!HashTraits<AXID>::isDeletedValue(axID));
     if (!axID)
         return 0;
 
@@ skipping 126 matching lines @@
         return AXMenuListOption::create(toHTMLOptionElement(node), *this);
 
     return AXNodeObject::create(node, *this);
 }
 
 AXObject* AXObjectCacheImpl::createFromInlineTextBox(AbstractInlineTextBox* inlineTextBox)
 {
     return AXInlineTextBox::create(inlineTextBox, *this);
 }
 
-AXObject* AXObjectCacheImpl::getOrCreate(Widget* widget)
-{
-    if (!widget)
-        return 0;
-
-    if (AXObject* obj = get(widget))
-        return obj;
-
-    AXObject* newObj = nullptr;
-    if (widget->isFrameView()) {
-        FrameView* frameView = toFrameView(widget);
-
-        // Don't create an AXScrollView for a FrameView that isn't attached to a frame,
-        // for example if it's in the process of being disposed.
-        if (frameView->frame().view() != frameView || !frameView->layoutView())
-            return 0;
-
-        newObj = AXScrollView::create(toFrameView(widget), *this);
-    } else if (widget->isScrollbar()) {
-        newObj = AXScrollbar::create(toScrollbar(widget), *this);
-    }
-
-    // Will crash later if we have two objects for the same widget.
-    ASSERT(!get(widget));
-
-    // Catch the case if an (unsupported) widget type is used. Only FrameView and ScrollBar are supported now.
-    ASSERT(newObj);
-    if (!newObj)
-        return 0;
-
-    getAXID(newObj);
-
-    m_widgetObjectMapping.set(widget, newObj->axObjectID());
-    m_objects.set(newObj->axObjectID(), newObj);
-    newObj->init();
-    return newObj;
-}
-
 AXObject* AXObjectCacheImpl::getOrCreate(Node* node)
 {
     if (!node)
         return 0;
 
     if (AXObject* obj = get(node))
         return obj;
 
     if (node->layoutObject())
         return getOrCreate(node->layoutObject());
 
     if (!node->parentElement())
         return 0;
 
     if (isHTMLHeadElement(node))
         return 0;
 
+    if (!node->document().frame())
+        return 0;
+
+    if (node->document().frame()->pagePopupOwner() && &node->document().frame()->pagePopupOwner()->document() != m_document)
+        return 0;
+
+    if (&node->document() != m_document)
+        return 0;
+
     AXObject* newObj = createFromNode(node);
 
     // Will crash later if we have two objects for the same node.
     ASSERT(!get(node));
 
     getAXID(newObj);
 
     m_nodeObjectMapping.set(node, newObj->axObjectID());
     m_objects.set(newObj->axObjectID(), newObj);
     newObj->init();
     newObj->setLastKnownIsIgnoredValue(newObj->accessibilityIsIgnored());
 
     if (node->isElementNode())
         updateTreeIfElementIdIsAriaOwned(toElement(node));
 
     return newObj;
 }
 
 AXObject* AXObjectCacheImpl::getOrCreate(LayoutObject* layoutObject)
 {
     if (!layoutObject)
         return 0;
 
+    if (&layoutObject->document() != m_document)
+        return 0;
+
     if (AXObject* obj = get(layoutObject))
         return obj;
 
     AXObject* newObj = createFromRenderer(layoutObject);
 
     // Will crash later if we have two objects for the same layoutObject.
     ASSERT(!get(layoutObject));
 
     getAXID(newObj);
 
@@ skipping 26 matching lines @@
     newObj->setLastKnownIsIgnoredValue(newObj->accessibilityIsIgnored());
 
     return newObj;
 }
 
 AXObject* AXObjectCacheImpl::rootObject()
 {
     if (!accessibilityEnabled())
         return 0;
 
-    return getOrCreate(m_document->view());
+    return getOrCreate(m_document);
 }
 
 AXObject* AXObjectCacheImpl::getOrCreate(AccessibilityRole role)
 {
     AXObject* obj = nullptr;
 
     // will be filled in...
     switch (role) {
     case ImageMapLinkRole:
         obj = AXImageMapLink::create(*this);
@@ skipping 69 matching lines @@
     AXID axID = m_nodeObjectMapping.get(node);
     remove(axID);
     m_nodeObjectMapping.remove(node);
 
     if (node->layoutObject()) {
         remove(node->layoutObject());
         return;
     }
 }
 
-void AXObjectCacheImpl::remove(Widget* view)
-{
-    if (!view)
-        return;
-
-    AXID axID = m_widgetObjectMapping.get(view);
-    remove(axID);
-    m_widgetObjectMapping.remove(view);
-}
-
 void AXObjectCacheImpl::remove(AbstractInlineTextBox* inlineTextBox)
 {
     if (!inlineTextBox)
         return;
 
     AXID axID = m_inlineTextBoxObjectMapping.get(inlineTextBox);
     remove(axID);
     m_inlineTextBoxObjectMapping.remove(inlineTextBox);
 }
 
@@ skipping 376 matching lines @@
 
 void AXObjectCacheImpl::listboxActiveIndexChanged(HTMLSelectElement* select)
 {
     AXObject* obj = get(select);
     if (!obj || !obj->isAXListBox())
         return;
 
     toAXListBox(obj)->activeIndexChanged();
 }
 
-void AXObjectCacheImpl::handleScrollbarUpdate(FrameView* view)
-{
-    if (!view)
-        return;
-
-    // We don't want to create a scroll view from this method, only update an existing one.
-    if (AXObject* scrollViewObject = get(view)) {
-        m_modificationCount++;
-        scrollViewObject->updateChildrenIfNecessary();
-    }
-}
-
 void AXObjectCacheImpl::handleLayoutComplete(LayoutObject* layoutObject)
 {
     if (!layoutObject)
         return;
 
     m_modificationCount++;
 
     // Create the AXObject if it didn't yet exist - that's always safe at the end of a layout, and it
     // allows an AX notification to be sent when a page has its first layout, rather than when the
     // document first loads.
@@ skipping 167 matching lines @@
         return false;
 
     if (!node->isElementNode())
         return false;
 
     return equalIgnoringCase(toElement(node)->getAttribute(aria_hiddenAttr), "false");
 }
 
 void AXObjectCacheImpl::postPlatformNotification(AXObject* obj, AXNotification notification)
 {
-    if (obj && obj->isAXScrollbar() && notification == AXValueChanged) {
-        // Send document value changed on scrollbar value changed notification.
-        Scrollbar* scrollBar = toAXScrollbar(obj)->scrollbar();
-        if (!scrollBar || !scrollBar->parent() || !scrollBar->parent()->isFrameView())
-            return;
-        Document* document = toFrameView(scrollBar->parent())->frame().document();
-        if (document != document->topDocument())
-            return;
-        obj = get(document->layoutView());
-    }
-
     if (!obj || !obj->document() || !obj->documentFrameView() || !obj->documentFrameView()->frame().page())
         return;
 
     ChromeClient& client = obj->document()->axObjectCacheOwner().page()->chromeClient();
 
     if (notification == AXActiveDescendantChanged
         && obj->document()->focusedElement()
         && obj->node() == obj->document()->focusedElement()) {
         // Calling handleFocusedUIElementChanged will focus the new active
         // descendant and send the AXFocusedUIElementChanged notification.
         handleFocusedUIElementChanged(0, obj->document()->focusedElement());
     }
 
     client.postAccessibilityNotification(obj, notification);
 }
 
 void AXObjectCacheImpl::handleFocusedUIElementChanged(Node*, Node* newFocusedNode)
 {
     if (!newFocusedNode)
+        newFocusedNode = m_document.get();

[aboxhall, 2015/09/22 21:48:27]

This seems like a major change. Is this functionally equivalent to what we had
before or is this new?

[dmazzoni, 2015/09/22 22:08:44]

This is more or less equivalent.

Internally, a document's active element can be null. From the perspective of
JavaScript, document.activeElement returns the body if nothing has focus. We're
just doing the same thing now, firing a focus event on the body if nothing
within a particular frame has focus.

This wasn't needed before because we could detect when nothing in the page had
focus at all from Chromium code. That trick won't work anymore because we need
to know what's focused in every single frame now.

+
+    AXObject* obj = getOrCreate(newFocusedNode);
+
+    if (isHTMLAreaElement(newFocusedNode))

[aboxhall, 2015/09/22 21:48:27]

Can you explain why this is now needed?

[dmazzoni, 2015/09/22 22:08:44]

This is just coming from AXObjectCacheImpl::focusedUIElementForPage. When an
AREA element has focus, we set accessibility focus to the element within the
image map that has focus. It's kind of like active descendant. This isn't new,
we just have to do that check in this place now.

+        obj = focusedImageMapUIElement(toHTMLAreaElement(newFocusedNode));
+
+    if (!obj)
         return;
 
-    Page* page = newFocusedNode->document().page();
-    if (!page)
-        return;
+    if (obj->shouldFocusActiveDescendant()) {
+        if (AXObject* descendant = obj->activeDescendant())
+            obj = descendant;
+    }
 
-    AXObject* focusedObject = focusedUIElementForPage(page);
-    if (!focusedObject)
-        return;
+    if (obj->accessibilityIsIgnored())
+        obj = obj->parentObjectUnignored();
 
-    postPlatformNotification(focusedObject, AXFocusedUIElementChanged);
+    postPlatformNotification(obj, AXFocusedUIElementChanged);
 }
 
 void AXObjectCacheImpl::handleInitialFocus()
 {
     postNotification(m_document, AXObjectCache::AXFocusedUIElementChanged);
 }
 
 void AXObjectCacheImpl::handleEditableTextContentChanged(Node* node)
 {
     AXObject* obj = get(node);
@@ skipping 51 matching lines @@
 
 void AXObjectCacheImpl::handleScrolledToAnchor(const Node* anchorNode)
 {
     // The anchor node may not be accessible. Post the notification for the
     // first accessible object.
     postPlatformNotification(firstAccessibleObjectFromNode(anchorNode), AXScrolledToAnchor);
 }
 
 void AXObjectCacheImpl::handleScrollPositionChanged(FrameView* frameView)
 {
-    // Prefer to fire the scroll position changed event on the frame view's child web area, if possible.
-    AXObject* targetAXObject = getOrCreate(frameView);
-    if (targetAXObject && !targetAXObject->children().isEmpty())
-        targetAXObject = targetAXObject->children()[0].get();
+    Document* doc = frameView->frame().document();
+    AXObject* targetAXObject = getOrCreate(doc);
     postPlatformNotification(targetAXObject, AXScrollPositionChanged);
 }
 
 void AXObjectCacheImpl::handleScrollPositionChanged(LayoutObject* layoutObject)
 {
     postPlatformNotification(getOrCreate(layoutObject), AXScrollPositionChanged);
 }
 
 const AtomicString& AXObjectCacheImpl::computedRoleForNode(Node* node)
 {
@@ skipping 45 matching lines @@
     if (!obj)
         return;
 
     obj->setElementRect(rect);
 }
 
 DEFINE_TRACE(AXObjectCacheImpl)
 {
 #if ENABLE(OILPAN)
     visitor->trace(m_document);
-    visitor->trace(m_widgetObjectMapping);
     visitor->trace(m_nodeObjectMapping);
 #endif
 
     visitor->trace(m_objects);
     visitor->trace(m_notificationsToPost);
 
     AXObjectCache::trace(visitor);
 }
 
 } // namespace blink