Function getNextElement

docs/app/js/sanddance-app.js:24645–24661

(rootElement, currentElement, checkNode, suppressParentTraversal, suppressChildTraversal, includeElementsInFocusZones, allowFocusRoot, tabbable)

    return null;
}
function getNextElement(rootElement, currentElement, checkNode, suppressParentTraversal, suppressChildTraversal, includeElementsInFocusZones, allowFocusRoot, tabbable) {
    if (!currentElement || currentElement === rootElement && suppressChildTraversal && !allowFocusRoot) return null;
    var isCurrentElementVisible = isElementVisible(currentElement);
    // Check the current node, if it's not the first traversal.
    if (checkNode && isCurrentElementVisible && isElementTabbable(currentElement, tabbable)) return currentElement;
    // Check its children.
    if (!suppressChildTraversal && isCurrentElementVisible && (includeElementsInFocusZones || !(isElementFocusZone(currentElement) || isElementFocusSubZone(currentElement)))) {
        var childMatch = getNextElement(rootElement, currentElement.firstElementChild, true, true, false, includeElementsInFocusZones, allowFocusRoot, tabbable);
        if (childMatch) return childMatch;
    }
    if (currentElement === rootElement) return null;
    // Check its sibling.
    var siblingMatch = getNextElement(rootElement, currentElement.nextElementSibling, true, true, false, includeElementsInFocusZones, allowFocusRoot, tabbable);
    if (siblingMatch) return siblingMatch;
    if (!suppressParentTraversal) return getNextElement(rootElement, currentElement.parentElement, false, false, true, includeElementsInFocusZones, allowFocusRoot, tabbable);
    return null;
}
function isElementVisible(element) {
    // If the element is not valid, return false.
    if (!element || !element.getAttribute) return false;