getElementDocumentPosition function
Implementation
Pair<num> getElementDocumentPosition(HTMLElement element) {
var obj = getVisibleNode(element);
num top = 0;
num left = 0;
while (obj != null) {
top += obj.offsetTop;
left += obj.offsetLeft;
obj = obj.offsetParent?.asHTMLElementChecked;
}
return Pair<num>(left, top);
}