<!DOCTYPE html>
<html>
<!--
Copyright The Closure Library Authors. All Rights Reserved.
Use of this source code is governed by the Apache License, Version 2.0.
See the COPYING file for details.
-->
<head>
<title>goog.events.MouseWheelHandler</title>
<link rel="stylesheet" href="../css/checkbox.css">
<style>
#out {
background-color: #eee;
width: 200px;
height: 200px;
position: relative;
}
#h-line, #v-line {
position: absolute;
background: black;
}
#h-line {
width: 20px;
height: 1px;
}
#v-line {
width: 1px;
height: 20px;
}
#status {
position: absolute;
bottom: 0;
right: 0;
font: 70% sans-serif;
}
</style>
<script src="../base.js"></script>
<script>
goog.require('goog.events');
goog.require('goog.events.MouseWheelHandler');
</script>
</head>
<body>
<h1>goog.events.MouseWheelHandler</h1>
<p>Use your mousewheel on the gray box below to move the cross hair.
<div id=out>
<div id=h-line></div>
<div id=v-line></div>
<div id=status></div>
</div>
<script>
var MouseWheelHandler = goog.events.MouseWheelHandler;
var MOUSEWHEEL = MouseWheelHandler.EventType.MOUSEWHEEL;
function $(id) {
return document.getElementById(id)
}
var x = 100, y = 100;
var out = $('out');
var hLine= $('h-line');
var vLine = $('v-line');
var status = $('status');
var availWidth = out.clientWidth - vLine.offsetWidth;
var availHeight = out.clientHeight - hLine.offsetHeight;
function handleMouseWheel(e) {
x += e.deltaX / 3;
x = Math.max(0, Math.min(availWidth, x));
y += e.deltaY / 3;
y = Math.max(0, Math.min(availHeight, y));
updateLines();
e.preventDefault();
}
function updateLines() {
vLine.style.left = x + 'px';
hLine.style.left = x - hLine.offsetWidth / 2 + 'px';
hLine.style.top = y + 'px';
vLine.style.top = y - vLine.offsetHeight / 2 + 'px';
status.innerHTML = x + ', ' + y;
}
updateLines();
var mwh = new MouseWheelHandler(out);
goog.events.listen(mwh, MOUSEWHEEL, handleMouseWheel);
goog.events.listen(window, 'unload', function(e) {
goog.events.unlisten(mwh, MOUSEWHEEL, handleMouseWheel);
});
</script>
</body>
</html>