C++ AccessibilityObject::accessibilityIsIgnored方法代码示例

void AccessibilityARIAGrid::addChildren()
{
    ASSERT(!m_haveChildren); 
    
    if (!isAccessibilityTable()) {
        AccessibilityRenderObject::addChildren();
        return;
    }
    
    m_haveChildren = true;
    if (!m_renderer)
        return;
    
    AXObjectCache* axCache = m_renderer->document().axObjectCache();
    
    // add only rows that are labeled as aria rows
    HashSet<AccessibilityObject*> appendedRows;
    unsigned columnCount = 0;
    for (RefPtr<AccessibilityObject> child = firstChild(); child; child = child->nextSibling())
        addRowDescendant(child.get(), appendedRows, columnCount);
    
    // make the columns based on the number of columns in the first body
    for (unsigned i = 0; i < columnCount; ++i) {
        AccessibilityTableColumn* column = toAccessibilityTableColumn(axCache->getOrCreate(ColumnRole));
        column->setColumnIndex((int)i);
        column->setParent(this);
        m_columns.append(column);
        if (!column->accessibilityIsIgnored())
            m_children.append(column);
    }
    
    AccessibilityObject* headerContainerObject = headerContainer();
    if (headerContainerObject && !headerContainerObject->accessibilityIsIgnored())
        m_children.append(headerContainerObject);
}

AccessibilityRole AccessibilityNodeObject::remapAriaRoleDueToParent(AccessibilityRole role) const
{
    // Some objects change their role based on their parent.
    // However, asking for the unignoredParent calls accessibilityIsIgnored(), which can trigger a loop. 
    // While inside the call stack of creating an element, we need to avoid accessibilityIsIgnored().
    // https://bugs.webkit.org/show_bug.cgi?id=65174

    if (role != ListBoxOptionRole && role != MenuItemRole)
        return role;
    
    for (AccessibilityObject* parent = parentObject(); parent && !parent->accessibilityIsIgnored(); parent = parent->parentObject()) {
        AccessibilityRole parentAriaRole = parent->ariaRoleAttribute();

        // Selects and listboxes both have options as child roles, but they map to different roles within WebCore.
        if (role == ListBoxOptionRole && parentAriaRole == MenuRole)
            return MenuItemRole;
        // An aria "menuitem" may map to MenuButton or MenuItem depending on its parent.
        if (role == MenuItemRole && parentAriaRole == GroupRole)
            return MenuButtonRole;
        
        // If the parent had a different role, then we don't need to continue searching up the chain.
        if (parentAriaRole)
            break;
    }
    
    return role;
}   

AccessibilityObject* AccessibilityListBox::elementAccessibilityHitTest(const LayoutPoint& point) const
{
    // the internal HTMLSelectElement methods for returning a listbox option at a point
    // ignore optgroup elements.
    if (!m_renderer)
        return 0;
    
    Node* node = m_renderer->node();
    if (!node)
        return 0;
    
    LayoutRect parentRect = boundingBoxRect();
    
    AccessibilityObject* listBoxOption = 0;
    unsigned length = m_children.size();
    for (unsigned i = 0; i < length; i++) {
        LayoutRect rect = toRenderListBox(m_renderer)->itemBoundingBoxRect(parentRect.location(), i);
        // The cast to HTMLElement below is safe because the only other possible listItem type
        // would be a WMLElement, but WML builds don't use accessibility features at all.
        if (rect.contains(point)) {
            listBoxOption = m_children[i].get();
            break;
        }
    }
    
    if (listBoxOption && !listBoxOption->accessibilityIsIgnored())
        return listBoxOption;
    
    return axObjectCache()->getOrCreate(m_renderer);
}

static gint webkitAccessibleTextGetCaretOffset(AtkText* text)
{
    // coreObject is the unignored object whose offset the caller is requesting.
    // focusedObject is the object with the caret. It is likely ignored -- unless it's a link.
    AccessibilityObject* coreObject = core(text);
    if (!coreObject->isAccessibilityRenderObject())
        return 0;

    // We need to make sure we pass a valid object as reference.
    if (coreObject->accessibilityIsIgnored())
        coreObject = coreObject->parentObjectUnignored();
    if (!coreObject)
        return 0;

    int offset;
    if (!objectFocusedAndCaretOffsetUnignored(coreObject, offset))
        return 0;

    RenderObject* renderer = coreObject->renderer();
    if (renderer && renderer->isListItem()) {
        String markerText = toRenderListItem(renderer)->markerTextWithSuffix();

        // We need to adjust the offset for the list item marker.
        offset += markerText.length();
    }

    // TODO: Verify this for RTL text.
    return offset;
}

AccessibilityObject* AXObjectCache::focusedUIElementForPage(const Page* page)
{
    if (!gAccessibilityEnabled)
        return 0;

    // get the focused node in the page
    Document* focusedDocument = page->focusController()->focusedOrMainFrame()->document();
    Node* focusedNode = focusedDocument->focusedNode();
    if (!focusedNode)
        focusedNode = focusedDocument;

    if (focusedNode->hasTagName(areaTag))
        return focusedImageMapUIElement(static_cast<HTMLAreaElement*>(focusedNode));
    
    AccessibilityObject* obj = focusedNode->document()->axObjectCache()->getOrCreate(focusedNode);
    if (!obj)
        return 0;

    if (obj->shouldFocusActiveDescendant()) {
        if (AccessibilityObject* 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;
}

bool AccessibilityList::childHasPseudoVisibleListItemMarkers(RenderObject* listItem)
{
    // Check if the list item has a pseudo-element that should be accessible (e.g. an image or text)
    Element* listItemElement = downcast<Element>(listItem->node());
    if (!listItemElement || !listItemElement->beforePseudoElement())
        return false;

    AccessibilityObject* axObj = axObjectCache()->getOrCreate(listItemElement->beforePseudoElement()->renderer());
    if (!axObj)
        return false;
    
    if (!axObj->accessibilityIsIgnored())
        return true;
    
    for (const auto& child : axObj->children()) {
        if (!child->accessibilityIsIgnored())
            return true;
    }
    
    // Platforms which expose rendered text content through the parent element will treat
    // those renderers as "ignored" objects.
#if PLATFORM(GTK) || PLATFORM(EFL)
    String text = axObj->textUnderElement();
    return !text.isEmpty() && !text.containsOnlyWhitespace();
#else
    return false;
#endif
}

AccessibilityObject* AccessibilityObject::firstAccessibleObjectFromNode(const Node* node)
{
    ASSERT(AXObjectCache::accessibilityEnabled());

    if (!node)
        return 0;

    Document* document = node->document();
    if (!document)
        return 0;

    AXObjectCache* cache = document->axObjectCache();

    AccessibilityObject* accessibleObject = cache->getOrCreate(node->renderer());
    while (accessibleObject && accessibleObject->accessibilityIsIgnored()) {
        node = node->traverseNextNode();

        while (node && !node->renderer())
            node = node->traverseNextSibling();

        if (!node)
            return 0;

        accessibleObject = cache->getOrCreate(node->renderer());
    }

    return accessibleObject;
}

AccessibilityObject* AccessibilityObject::parentObjectUnignored() const
{
    AccessibilityObject* parent;
    for (parent = parentObject(); parent && parent->accessibilityIsIgnored(); parent = parent->parentObject())
        ;
    return parent;
}

AccessibilityObject* AccessibilityObject::firstAccessibleObjectFromNode(const Node* node)
{
    if (!node)
        return 0;

    Document* document = node->document();
    if (!document)
        return 0;

    AXObjectCache* cache = document->axObjectCache();

    AccessibilityObject* accessibleObject = cache->getOrCreate(node->renderer());
    while (accessibleObject && accessibleObject->accessibilityIsIgnored()) {
        node = NodeTraversal::next(node);

        while (node && !node->renderer())
            node = NodeTraversal::nextSkippingChildren(node);

        if (!node)
            return 0;

        accessibleObject = cache->getOrCreate(node->renderer());
    }

    return accessibleObject;
}

bool AccessibilityScrollView::computeAccessibilityIsIgnored() const
{
    AccessibilityObject* webArea = webAreaObject();
    if (!webArea)
        return true;
    
    return webArea->accessibilityIsIgnored();
}

void AccessibilityScrollView::addChildren()
{
    ASSERT(!m_haveChildren);
    m_haveChildren = true;
    
    AccessibilityObject* webArea = webAreaObject();
    if (webArea && !webArea->accessibilityIsIgnored())
        m_children.append(webArea);
    
    updateScrollbars();
}

void AccessibilityARIAGrid::addChildren()
{
    ASSERT(!m_haveChildren); 
    
    if (!isAccessibilityTable()) {
        AccessibilityRenderObject::addChildren();
        return;
    }
    
    m_haveChildren = true;
    if (!m_renderer)
        return;
    
    AXObjectCache* axCache = m_renderer->document().axObjectCache();
    
    // Add the children rows but be mindful in case there are footer sections in this table.
    HashSet<AccessibilityObject*> appendedRows;
    unsigned columnCount = 0;
    AccessibilityChildrenVector footerSections;
    for (RefPtr<AccessibilityObject> child = firstChild(); child; child = child->nextSibling()) {
        bool footerSection = false;
        if (RenderObject* childRenderer = child->renderer()) {
            if (childRenderer->isTableSection()) {
                if (RenderTableSection* childSection = toRenderTableSection(childRenderer)) {
                    if (childSection == childSection->table()->footer()) {
                        footerSections.append(child);
                        footerSection = true;
                    }
                }
            }
        }
        if (!footerSection)
            addRowDescendant(child.get(), appendedRows, columnCount);
    }
    
    for (const auto& footerSection : footerSections)
        addRowDescendant(footerSection.get(), appendedRows, columnCount);
    
    // make the columns based on the number of columns in the first body
    for (unsigned i = 0; i < columnCount; ++i) {
        AccessibilityTableColumn* column = toAccessibilityTableColumn(axCache->getOrCreate(ColumnRole));
        column->setColumnIndex((int)i);
        column->setParent(this);
        m_columns.append(column);
        if (!column->accessibilityIsIgnored())
            m_children.append(column);
    }
    
    AccessibilityObject* headerContainerObject = headerContainer();
    if (headerContainerObject && !headerContainerObject->accessibilityIsIgnored())
        m_children.append(headerContainerObject);
}

static bool replacedNodeNeedsCharacter(Node* replacedNode)
{
    // we should always be given a rendered node and a replaced node, but be safe
    // replaced nodes are either attachments (widgets) or images
    if (!replacedNode || !replacedNode->renderer() || !replacedNode->renderer()->isReplaced() || replacedNode->isTextNode())
        return false;

    // create an AX object, but skip it if it is not supposed to be seen
    AccessibilityObject* object = replacedNode->renderer()->document()->axObjectCache()->getOrCreate(replacedNode);
    if (object->accessibilityIsIgnored())
        return false;

    return true;
}

void AccessibilityARIAGrid::addChildren()
{
    ASSERT(!m_haveChildren); 
    
    if (!isAccessibilityTable()) {
        AccessibilityRenderObject::addChildren();
        return;
    }
    
    m_haveChildren = true;
    if (!m_renderer)
        return;
    
    AXObjectCache* axCache = m_renderer->document()->axObjectCache();
    
    // add only rows that are labeled as aria rows
    HashSet<AccessibilityObject*> appendedRows;
    unsigned columnCount = 0;
    for (RefPtr<AccessibilityObject> child = firstChild(); child; child = child->nextSibling()) {

        if (!addTableCellChild(child.get(), appendedRows, columnCount)) {
            
            // in case the render tree doesn't match the expected ARIA hierarchy, look at the children
            if (!child->hasChildren())
                child->addChildren();

            // The children of this non-row will contain all non-ignored elements (recursing to find them). 
            // This allows the table to dive arbitrarily deep to find the rows.
            AccessibilityChildrenVector children = child->children();
            size_t length = children.size();
            for (size_t i = 0; i < length; ++i)
                addTableCellChild(children[i].get(), appendedRows, columnCount);
        }
    }
    
    // make the columns based on the number of columns in the first body
    for (unsigned i = 0; i < columnCount; ++i) {
        AccessibilityTableColumn* column = static_cast<AccessibilityTableColumn*>(axCache->getOrCreate(ColumnRole));
        column->setColumnIndex((int)i);
        column->setParent(this);
        m_columns.append(column);
        if (!column->accessibilityIsIgnored())
            m_children.append(column);
    }
    
    AccessibilityObject* headerContainerObject = headerContainer();
    if (headerContainerObject && !headerContainerObject->accessibilityIsIgnored())
        m_children.append(headerContainerObject);
}

void AccessibilityListBox::addChildren()
{
    Node* selectNode = m_renderer->node();
    if (!selectNode)
        return;
    
    m_haveChildren = true;
    
    for (const auto& listItem : toHTMLSelectElement(selectNode)->listItems()) {
        // The cast to HTMLElement below is safe because the only other possible listItem type
        // would be a WMLElement, but WML builds don't use accessibility features at all.
        AccessibilityObject* listOption = listBoxOptionAccessibilityObject(listItem);
        if (listOption && !listOption->accessibilityIsIgnored())
            m_children.append(listOption);
    }
}