C++ AccessibilityObject类代码示例

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->renderer());
    if (object->accessibilityIsIgnored())
        return false;

    return true;
}

static AtkRole webkit_accessible_get_role(AtkObject* object)
{
    AccessibilityObject* AXObject = core(object);

    if (!AXObject)
        return ATK_ROLE_UNKNOWN;

    // WebCore does not seem to have a role for list items
    if (AXObject->isGroup()) {
        AccessibilityObject* parent = AXObject->parentObjectUnignored();
        if (parent && parent->isList())
            return ATK_ROLE_LIST_ITEM;
    }

    // WebCore does not know about paragraph role, label role, or section role
    if (AXObject->isAccessibilityRenderObject()) {
        Node* node = static_cast<AccessibilityRenderObject*>(AXObject)->renderer()->node();
        if (node) {
            if (node->hasTagName(HTMLNames::pTag))
                return ATK_ROLE_PARAGRAPH;
            if (node->hasTagName(HTMLNames::labelTag))
                return ATK_ROLE_LABEL;
            if (node->hasTagName(HTMLNames::divTag))
                return ATK_ROLE_SECTION;
        }
    }

    // Note: Why doesn't WebCore have a password field for this
    if (AXObject->isPasswordField())
        return ATK_ROLE_PASSWORD_TEXT;

    return atkRole(AXObject->roleValue());
}

static gchar* webkit_accessible_text_get_text(AtkText* text, gint startOffset, gint endOffset)
{
    AccessibilityObject* coreObject = core(text);
    String ret;
    unsigned start = startOffset;
    int length = endOffset - startOffset;

    if (coreObject->isTextControl())
        ret = coreObject->doAXStringForRange(PlainTextRange(start, length));
    else
        ret = coreObject->textUnderElement().substring(start, length);

    return g_strdup(ret.utf8().data());
}

String AccessibilityObject::language() const
{
    AccessibilityObject* parent = parentObject();
    
    // as a last resort, fall back to the content language specified in the meta tag
    if (!parent) {
        Document* doc = document();
        if (doc)
            return doc->contentLanguage();
        return String();
    }
    
    return parent->language();
}

void AccessibilityObject::ariaTreeItemContent(AccessibilityChildrenVector& result)
{
    // The ARIA tree item content are the item that are not other tree items or their containing groups.
    AccessibilityChildrenVector axChildren = children();
    unsigned count = axChildren.size();
    for (unsigned k = 0; k < count; ++k) {
        AccessibilityObject* obj = axChildren[k].get();
        AccessibilityRole role = obj->roleValue();
        if (role == TreeItemRole || role == GroupRole)
            continue;
        
        result.append(obj);
    }
}

static gint webkitAccessibleGetNChildren(AtkObject* object)
{
    g_return_val_if_fail(WEBKIT_IS_ACCESSIBLE(object), 0);
    returnValIfWebKitAccessibleIsInvalid(WEBKIT_ACCESSIBLE(object), 0);

    AccessibilityObject* coreObject = core(object);

    // Tables should be treated in a different way because rows should
    // be bypassed when exposing the accessible hierarchy.
    if (coreObject->isAccessibilityTable())
        return getNChildrenForTable(coreObject);

    return coreObject->children().size();
}

static void modifyAccessibilityValue(AtkObject* axObject, bool increment)
{
    if (!axObject || !WEBKIT_IS_ACCESSIBLE(axObject))
        return;

    AccessibilityObject* coreObject = webkit_accessible_get_accessibility_object(WEBKIT_ACCESSIBLE(axObject));
    if (!coreObject)
        return;

    if (increment)
        coreObject->increment();
    else
        coreObject->decrement();
}

void AXObjectCache::nodeTextChangePlatformNotification(AccessibilityObject* object, AXTextChange textChange, unsigned offset, const String& text)
{
    if (!object || text.isEmpty())
        return;

    AccessibilityObject* parentObject = object->parentObjectUnignored();
    if (!parentObject)
        return;

    AtkObject* wrapper = parentObject->wrapper();
    if (!wrapper || !ATK_IS_TEXT(wrapper))
        return;

    Node* node = object->node();
    if (!node)
        return;

    // Ensure document's layout is up-to-date before using TextIterator.
    Document& document = node->document();
    document.updateLayout();

    // Select the right signal to be emitted
    CString detail;
    switch (textChange) {
    case AXObjectCache::AXTextInserted:
        detail = "text-insert";
        break;
    case AXObjectCache::AXTextDeleted:
        detail = "text-remove";
        break;
    }

    String textToEmit = text;
    unsigned offsetToEmit = offset;

    // If the object we're emitting the signal from represents a
    // password field, we will emit the masked text.
    if (parentObject->isPasswordField()) {
        String maskedText = parentObject->passwordFieldValue();
        textToEmit = maskedText.substring(offset, text.length());
    } else {
        // Consider previous text objects that might be present for
        // the current accessibility object to ensure we emit the
        // right offset (e.g. multiline text areas).
        RefPtr<Range> range = Range::create(document, node->parentNode(), 0, node, 0);
        offsetToEmit = offset + TextIterator::rangeLength(range.get());
    }

    g_signal_emit_by_name(wrapper, detail.data(), offsetToEmit, textToEmit.length(), textToEmit.utf8().data());
}

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);
}

AtkObject* webkitAccessibleTableCellGetTable(AtkTableCell* cell)
{
    g_return_val_if_fail(ATK_TABLE_CELL(cell), nullptr);
    returnValIfWebKitAccessibleIsInvalid(WEBKIT_ACCESSIBLE(cell), nullptr);

    AccessibilityObject* axObject = core(cell);
    if (!axObject || !axObject->isTableCell())
        return nullptr;

    AtkObject* table = atk_object_get_parent(axObject->wrapper());
    if (!table || !ATK_IS_TABLE(table))
        return nullptr;

    return ATK_OBJECT(g_object_ref(table));
}

void AccessibilityMenuListPopup::childrenChanged()
{
    AXObjectCache* cache = axObjectCache();
    for (size_t i = m_children.size(); i > 0 ; --i) {
        AccessibilityObject* child = m_children[i - 1].get();
        if (child->actionElement() && !child->actionElement()->inRenderedDocument()) {
            child->detachFromParent();
            cache->remove(child->axObjectID());
        }
    }
    
    m_children.clear();
    m_haveChildren = false;
    addChildren();
}

void AccessibilityObject::ariaTreeItemDisclosedRows(AccessibilityChildrenVector& result)
{
    AccessibilityChildrenVector axChildren = children();
    unsigned count = axChildren.size();
    for (unsigned k = 0; k < count; ++k) {
        AccessibilityObject* obj = axChildren[k].get();
        
        // Add tree items as the rows.
        if (obj->roleValue() == TreeItemRole)
            result.append(obj);
        // If it's not a tree item, then descend into the group to find more tree items.
        else 
            obj->ariaTreeRows(result);
    }    
}

static gboolean webkitAccessibleHyperlinkActionDoAction(AtkAction* action, gint index)
{
    g_return_val_if_fail(WEBKIT_IS_ACCESSIBLE_HYPERLINK(action), FALSE);
    g_return_val_if_fail(WEBKIT_ACCESSIBLE_HYPERLINK(action)->priv->hyperlinkImpl, FALSE);
    g_return_val_if_fail(!index, FALSE);

    if (!ATK_IS_ACTION(WEBKIT_ACCESSIBLE_HYPERLINK(action)->priv->hyperlinkImpl))
        return FALSE;

    AccessibilityObject* coreObject = core(action);
    if (!coreObject)
        return FALSE;

    return coreObject->performDefaultAction();
}

AccessibilityTable* AccessibilityARIAGridRow::parentTable() const
{
    // The parent table might not be the direct ancestor of the row unfortunately. ARIA states that role="grid" should
    // only have "row" elements, but if not, we still should handle it gracefully by finding the right table.
    for (AccessibilityObject* parent = parentObject(); parent; parent = parent->parentObject()) {
        // The parent table for an ARIA grid row should be an ARIA table.
        if (is<AccessibilityTable>(*parent)) {
            AccessibilityTable& tableParent = downcast<AccessibilityTable>(*parent);
            if (tableParent.isExposableThroughAccessibility() && tableParent.isAriaTable())
                return &tableParent;
        }
    }
    
    return nullptr;
}

static gboolean webkitAccessibleSelectionIsChildSelected(AtkSelection* selection, gint index)
{
    g_return_val_if_fail(ATK_SELECTION(selection), FALSE);
    returnValIfWebKitAccessibleIsInvalid(WEBKIT_ACCESSIBLE(selection), FALSE);

    AccessibilityObject* coreSelection = core(selection);
    if (!coreSelection)
        return FALSE;

    AccessibilityObject* option = optionFromList(selection, index);
    if (option && (coreSelection->isListBox() || coreSelection->isMenuList()))
        return option->isSelected();

    return FALSE;
}