def compare(elem1, elem2):
    JS("""
    if (!@{{elem1}} && !@{{elem2}}) {
        return true;
    } else if (!@{{elem1}} || !@{{elem2}}) {
        return false;
    }
	if (!@{{elem1}}.isSameNode) {
	    return (@{{elem1}} == @{{elem2}});
	}
    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 elem = @{{_elem}};
    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 elem = @{{_elem}};
    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) {
			if (current == @{{child}}) {
			   return count;
		   }
		}
        else if (current.isSameNode(@{{child}})) {
            return count;
        }
        if (current.nodeType == 1) {
            ++count;
        }
        current = current.nextSibling;
    }
    return -1;
    """)

def isOrHasChild(parent, _child):
    JS("""
    var child = @{{_child}};
    while (child) {
        if ((!@{{parent}}.isSameNode)) {
            if (@{{parent}} == child) {
                return true;
            }
        }
        else if (@{{parent}}.isSameNode(child)) {
            return true;
        }
        try {
            child = child.parentNode;
        } catch(e) {
          // Give up on 'Permission denied to get property
          // HTMLDivElement.parentNode'
          // See https://bugzilla.mozilla.org/show_bug.cgi?id=208427
          return false;
        }
        if (child && (child.nodeType != 1)) {
          child = null;
        }
      }
    return false;
    """)

def releaseCapture(elem):
    JS("""
    if ((@{{sCaptureElem}} != null) && @{{compare}}(@{{elem}}, @{{sCaptureElem}}))
        @{{sCaptureElem}} = null;
    
	if (!@{{elem}}.isSameNode) {
		if (@{{elem}} == $wnd.__captureElem) {
			$wnd.__captureElem = null;
		}
	}
	else if (@{{elem}}.isSameNode($wnd.__captureElem)) {
        $wnd.__captureElem = null;
    }
    """)
