[JS] 마우스 휠 제어

/* This is high-level function. */
function handle(delta) {
    var s = delta + ": ";
    if (delta < 0) s += "down";
    else s += "up";
    document.getElementById("delta").innerHTML = s;
}
 
/* Event handler for mouse wheel event. */
function wheel(event){
    var delta = 0;
    if (!event) event = window.event;
    if (event.wheelDelta) {
        delta = event.wheelDelta/120;
        if (window.opera) delta = -delta;
    } else if (event.detail) delta = -event.detail/3;
    if (delta) handle(delta);
}
 
/* Initialization code. */
if (window.addEventListener)
window.addEventListener("DOMMouseScroll", wheel, false);
window.onmousewheel = document.onmousewheel = wheel;