2 * hoverIntent is similar to jQuery's built-in "hover" function except that
3 * instead of firing the onMouseOver event immediately, hoverIntent checks
4 * to see if the user's mouse has slowed down (beneath the sensitivity
5 * threshold) before firing the onMouseOver event.
7 * hoverIntent r5 // 2007.03.27 // jQuery 1.1.2
8 * <http://cherne.net/brian/resources/jquery.hoverIntent.html>
10 * hoverIntent is currently available for use in all personal or commercial
11 * projects under both MIT and GPL licenses. This means that you can choose
12 * the license that best suits your project, and use it accordingly.
14 * // basic usage (just like .hover) receives onMouseOver and onMouseOut functions
15 * $("ul li").hoverIntent( showNav , hideNav );
17 * // advanced usage receives configuration object only
18 * $("ul li").hoverIntent({
19 * sensitivity: 2, // number = sensitivity threshold (must be 1 or higher)
20 * interval: 50, // number = milliseconds of polling interval
21 * over: showNav, // function = onMouseOver callback (required)
22 * timeout: 100, // number = milliseconds delay before onMouseOut function call
23 * out: hideNav // function = onMouseOut callback (required)
26 * @param f onMouseOver function || An object with configuration options
27 * @param g onMouseOut function || Nothing (use configuration options object)
28 * @return The object (aka "this") that called hoverIntent, and the event object
29 * @author Brian Cherne <brian@cherne.net>
32 $.fn.hoverIntent = function(f,g) {
33 // default configuration options
39 // override configuration options with user supplied object
40 cfg = $.extend(cfg, g ? { over: f, out: g } : f );
42 // instantiate variables
43 // cX, cY = current X and Y position of mouse, updated by mousemove event
44 // pX, pY = previous X and Y position of mouse, set by mouseover and polling interval
47 // A private function for getting mouse position
48 var track = function(ev) {
53 // A private function for comparing current and previous mouse position
54 var compare = function(ev,ob) {
55 ob.hoverIntent_t = clearTimeout(ob.hoverIntent_t);
56 // compare mouse positions to see if they've crossed the threshold
57 if ( ( Math.abs(pX-cX) + Math.abs(pY-cY) ) < cfg.sensitivity ) {
58 $(ob).unbind("mousemove",track);
59 // set hoverIntent state to true (so mouseOut can be called)
61 return cfg.over.apply(ob,[ev]);
63 // set previous coordinates for next time
65 // use self-calling timeout, guarantees intervals are spaced out properly (avoids JavaScript timer bugs)
66 ob.hoverIntent_t = setTimeout( function(){compare(ev, ob);} , cfg.interval );
70 // A private function for delaying the mouseOut function
71 var delay = function(ev,ob) {
72 ob.hoverIntent_t = clearTimeout(ob.hoverIntent_t);
74 return cfg.out.apply(ob,[ev]);
77 // A private function for handling mouse 'hovering'
78 var handleHover = function(e) {
79 // next three lines copied from jQuery.hover, ignore children onMouseOver/onMouseOut
80 var p = (e.type == "mouseover" ? e.fromElement : e.toElement) || e.relatedTarget;
81 while ( p && p != this ) { try { p = p.parentNode; } catch(e) { p = this; } }
82 if ( p == this ) { return false; }
84 // copy objects to be passed into t (required for event object to be passed in IE)
85 var ev = jQuery.extend({},e);
88 // cancel hoverIntent timer if it exists
89 if (ob.hoverIntent_t) { ob.hoverIntent_t = clearTimeout(ob.hoverIntent_t); }
91 // else e.type == "onmouseover"
92 if (e.type == "mouseover") {
93 // set "previous" X and Y position based on initial entry point
94 pX = ev.pageX; pY = ev.pageY;
95 // update "current" X and Y position based on mousemove
96 $(ob).bind("mousemove",track);
97 // start polling interval (self-calling timeout) to compare mouse coordinates over time
98 if (ob.hoverIntent_s != 1) { ob.hoverIntent_t = setTimeout( function(){compare(ev,ob);} , cfg.interval );}
100 // else e.type == "onmouseout"
102 // unbind expensive mousemove event
103 $(ob).unbind("mousemove",track);
104 // if hoverIntent state is true, then call the mouseOut function after the specified delay
105 if (ob.hoverIntent_s == 1) { ob.hoverIntent_t = setTimeout( function(){delay(ev,ob);} , cfg.timeout );}
109 // bind the function to the two event listeners
110 return this.mouseover(handleHover).mouseout(handleHover);