hoverIntent插件—实现子菜单延时显示可以防止鼠标经过时的误点击操作
<title>延时显示子菜单的方法</title>
<script type="text/javascript">
$(document).ready(function(){
$("#demo6").hoverIntent({
over: makeTall,
out: makeShort,
selector: 'li',
timeout:500
});
}); // close document.ready
function makeTall(){$(this).animate({"height":75},200);}
function makeShort(){$(this).animate({"height":50},200);}
</script>
<style type="text/css">
ul.demo {display:block; width:100%; height:75px; padding:0; margin:0; background:#9cc; list-style-type:none;}
ul.demo li {background:#fcc; display:block; width:25%; height:50px; padding:0; margin:0; float: left; position:relative; overflow:hidden; cursor:default; font-size:0.9em; line-height:1.1em;}
ul.demo li.p2 {background:#ffc;}
ul.demo li.p3 {background:#cfc;}
ul.demo li.p4 {background:#ccf;}
ul.demo li span { display:block; margin:4px; background:#eef; cursor:default;}
</style>
</head>
<body>
<div id="banner">
<ul id="demo6" class="demo">
<li class="p1"></li>
<li class="p2" ></li>
<li class="p3" ></li>
<li class="p4"></li>
</ul>
</div>
</body>下面是jquery.hoverIntent.js插件的具体实现
/*!
* hoverIntent r7 // 2013.03.11 // jQuery 1.9.1+
* http://cherne.net/brian/resources/jquery.hoverIntent.html
*
* You may use hoverIntent under the terms of the MIT license. Basically that
* means you are free to use hoverIntent as long as this header is left intact.
* Copyright 2007, 2013 Brian Cherne
*/
/* hoverIntent is similar to jQuery's built-in "hover" method except that
* instead of firing the handlerIn function immediately, hoverIntent checks
* to see if the user's mouse has slowed down (beneath the sensitivity
* threshold) before firing the event. The handlerOut function is only
* called after a matching handlerIn.
*
* // basic usage ... just like .hover()
* .hoverIntent( handlerIn, handlerOut )
* .hoverIntent( handlerInOut )
*
* // basic usage ... with event delegation!
* .hoverIntent( handlerIn, handlerOut, selector )
* .hoverIntent( handlerInOut, selector )
*
* // using a basic configuration object
* .hoverIntent( config )
*
* @param handlerIn function OR configuration object
* @param handlerOut function OR selector for delegation OR undefined
* @param selector selector OR undefined
* @author Brian Cherne <brian(at)cherne(dot)net>
*/
(function($) {
$.fn.hoverIntent = function(handlerIn,handlerOut,selector) {
// default configuration values
var cfg = {
interval: 100,
sensitivity: 7,
timeout: 0
};
if ( typeof handlerIn === "object" ) {
cfg = $.extend(cfg, handlerIn );
} else if ($.isFunction(handlerOut)) {
cfg = $.extend(cfg, { over: handlerIn, out: handlerOut, selector: selector } );
} else {
cfg = $.extend(cfg, { over: handlerIn, out: handlerIn, selector: handlerOut } );
}
// instantiate variables
// cX, cY = current X and Y position of mouse, updated by mousemove event
// pX, pY = previous X and Y position of mouse, set by mouseover and polling interval
var cX, cY, pX, pY;
// A private function for getting mouse position
var track = function(ev) {
cX = ev.pageX;
cY = ev.pageY;
};
// A private function for comparing current and previous mouse position
var compare = function(ev,ob) {
ob.hoverIntent_t = clearTimeout(ob.hoverIntent_t);
// compare mouse positions to see if they've crossed the threshold
if ( ( Math.abs(pX-cX) + Math.abs(pY-cY) ) < cfg.sensitivity ) {
$(ob).off("mousemove.hoverIntent",track);
// set hoverIntent state to true (so mouseOut can be called)
ob.hoverIntent_s = 1;
return cfg.over.apply(ob,[ev]);
} else {
// set previous coordinates for next time
pX = cX; pY = cY;
// use self-calling timeout, guarantees intervals are spaced out properly (avoids JavaScript timer bugs)
ob.hoverIntent_t = setTimeout( function(){compare(ev, ob);} , cfg.interval );
}
};
// A private function for delaying the mouseOut function
var delay = function(ev,ob) {
ob.hoverIntent_t = clearTimeout(ob.hoverIntent_t);
ob.hoverIntent_s = 0;
return cfg.out.apply(ob,[ev]);
};
// A private function for handling mouse 'hovering'
var handleHover = function(e) {
// copy objects to be passed into t (required for event object to be passed in IE)
var ev = jQuery.extend({},e);
var ob = this;
// cancel hoverIntent timer if it exists
if (ob.hoverIntent_t) { ob.hoverIntent_t = clearTimeout(ob.hoverIntent_t); }
// if e.type == "mouseenter"
if (e.type == "mouseenter") {
// set "previous" X and Y position based on initial entry point
pX = ev.pageX; pY = ev.pageY;
// update "current" X and Y position based on mousemove
$(ob).on("mousemove.hoverIntent",track);
// start polling interval (self-calling timeout) to compare mouse coordinates over time
if (ob.hoverIntent_s != 1) { ob.hoverIntent_t = setTimeout( function(){compare(ev,ob);} , cfg.interval );}
// else e.type == "mouseleave"
} else {
// unbind expensive mousemove event
$(ob).off("mousemove.hoverIntent",track);
// if hoverIntent state is true, then call the mouseOut function after the specified delay
if (ob.hoverIntent_s == 1) { ob.hoverIntent_t = setTimeout( function(){delay(ev,ob);} , cfg.timeout );}
}
};
// listen for mouseenter and mouseleave
return this.on({'mouseenter.hoverIntent':handleHover,'mouseleave.hoverIntent':handleHover}, cfg.selector);
};
})(jQuery);