def compare(elem1, elem2):
    JS("""
    if (!elem1 && !elem2) {
        return true;
    } else if (!elem1 || !elem2) {
        return false;
    }
    return (elem1.isSameNode(elem2));
    """)

def eventGetButton(evt):
    JS("""
    var button = evt.button;
    if(button == 0) {
        return 1;
    } else if (button == 1) {
        return 4;
    } else {
        return button;
    }
    """)

def getAbsoluteLeft(elem):
    JS("""
    var left = 0;
    var parent = elem;

    while (parent) {
        if (parent.scrollLeft > 0) {
            left = left -  parent.scrollLeft;
        }
        parent = parent.parentNode;
    }
    while (elem) {
        left = left + elem.offsetLeft;
        elem = elem.offsetParent;
    }

    return left + $doc.body.scrollLeft + $doc.documentElement.scrollLeft;
    """)

def getAbsoluteTop(elem):
    JS("""
    var top = 0;
    var parent = elem;
    while (parent) {
        if (parent.scrollTop > 0) {
            top -= parent.scrollTop;
        }
        parent = parent.parentNode;
    }

    while (elem) {
        top += elem.offsetTop;
        elem = elem.offsetParent;
    }
    return top + $doc.body.scrollTop + $doc.documentElement.scrollTop;
    """)

def getChildIndex(parent, child):
    JS("""
    var count = 0, current = parent.firstChild;
    while (current) {
        if (current.isSameNode(child)) {
            return count;
        }
        if (current.nodeType == 1) {
            ++count;
        }
        current = current.nextSibling;
    }
    return -1;
    """)

def isOrHasChild(parent, child):
    JS("""
    while (child) {
        if (parent.isSameNode(child)) {
            return true;
        }
        child = child.parentNode;
        if (child.nodeType != 1) {
            child = null;
        }
    }
    return false;
    """)

def releaseCapture(elem):
    JS("""
    if ((DOM_sCaptureElem != null) && DOM_compare(elem, DOM_sCaptureElem))
        DOM_sCaptureElem = null;
    
    if (elem.isSameNode($wnd.__captureElem)) {
        $wnd.__captureElem = null;
    }
    """)