Function setActiveElement

docs/app/js/sanddance-app.js:6717–6722

(activeElementInfo, container)

    if (input.setSelectionRange && activeElementInfo && activeElementInfo.selectionStart != null && activeElementInfo.selectionEnd != null) input.setSelectionRange(activeElementInfo.selectionStart, activeElementInfo.selectionEnd, activeElementInfo.selectionDirection);
}
function setActiveElement(activeElementInfo, container) {
    if (activeElementInfo) {
        const element = findElementByChildPositions(activeElementInfo.childPositions, container);
        if (element) focusActiveElement(element, activeElementInfo);
    }
}
function getActiveElementInfo(container) {
    let element = document.activeElement;
    const { scrollTop , selectionDirection , selectionEnd , selectionStart  } = element;