resources/lib/jquery.hoverIntent.js

   1 /**
   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.
   6 *
   7 * hoverIntent r5 // 2007.03.27 // jQuery 1.1.2+
   8 * <http://cherne.net/brian/resources/jquery.hoverIntent.html>
   9 *
  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.
  13 *
  14 * // basic usage (just like .hover) receives onMouseOver and onMouseOut functions
  15 * $("ul li").hoverIntent( showNav , hideNav );
  16 *
  17 * // advanced usage receives configuration object only
  18 * $("ul li").hoverIntent({
  19 *       sensitivity: 7, // number = sensitivity threshold (must be 1 or higher)
  20 *       interval: 100,   // number = milliseconds of polling interval
  21 *       over: showNav,  // function = onMouseOver callback (required)
  22 *       timeout: 0,   // number = milliseconds delay before onMouseOut function call
  23 *       out: hideNav    // function = onMouseOut callback (required)
  24 * });
  25 *
  26 * @param  f  onMouseOver function || An object with configuration options
  27 * @param  g  onMouseOut function  || Nothing (use configuration options object)
  28 * @author    Brian Cherne <brian@cherne.net>
  29 */
  30 (function($) {
  31         $.fn.hoverIntent = function(f,g) {
  32                 // default configuration options
  33                 var cfg = {
  34                         sensitivity: 7,
  35                         interval: 100,
  36                         timeout: 0
  37                 };
  38                 // override configuration options with user supplied object
  39                 cfg = $.extend(cfg, g ? { over: f, out: g } : f );
  40
  41                 // instantiate variables
  42                 // cX, cY = current X and Y position of mouse, updated by mousemove event
  43                 // pX, pY = previous X and Y position of mouse, set by mouseover and polling interval
  44                 var cX, cY, pX, pY;
  45
  46                 // A private function for getting mouse position
  47                 var track = function(ev) {
  48                         cX = ev.pageX;
  49                         cY = ev.pageY;
  50                 };
  51
  52                 // A private function for comparing current and previous mouse position
  53                 var compare = function(ev,ob) {
  54                         ob.hoverIntent_t = clearTimeout(ob.hoverIntent_t);
  55                         // compare mouse positions to see if they've crossed the threshold
  56                         if ( ( Math.abs(pX-cX) + Math.abs(pY-cY) ) < cfg.sensitivity ) {
  57                                 $(ob).unbind("mousemove",track);
  58                                 // set hoverIntent state to true (so mouseOut can be called)
  59                                 ob.hoverIntent_s = 1;
  60                                 return cfg.over.apply(ob,[ev]);
  61                         } else {
  62                                 // set previous coordinates for next time
  63                                 pX = cX; pY = cY;
  64                                 // use self-calling timeout, guarantees intervals are spaced out properly (avoids JavaScript timer bugs)
  65                                 ob.hoverIntent_t = setTimeout( function(){compare(ev, ob);} , cfg.interval );
  66                         }
  67                 };
  68
  69                 // A private function for delaying the mouseOut function
  70                 var delay = function(ev,ob) {
  71                         ob.hoverIntent_t = clearTimeout(ob.hoverIntent_t);
  72                         ob.hoverIntent_s = 0;
  73                         return cfg.out.apply(ob,[ev]);
  74                 };
  75
  76                 // A private function for handling mouse 'hovering'
  77                 var handleHover = function(e) {
  78                         // next three lines copied from jQuery.hover, ignore children onMouseOver/onMouseOut
  79                         var p = (e.type == "mouseover" ? e.fromElement : e.toElement) || e.relatedTarget;
  80                         while ( p && p != this ) { try { p = p.parentNode; } catch(e) { p = this; } }
  81                         if ( p == this ) { return false; }
  82
  83                         // copy objects to be passed into t (required for event object to be passed in IE)
  84                         var ev = $.extend({},e);
  85                         var ob = this;
  86
  87                         // cancel hoverIntent timer if it exists
  88                         if (ob.hoverIntent_t) { ob.hoverIntent_t = clearTimeout(ob.hoverIntent_t); }
  89
  90                         // else e.type == "onmouseover"
  91                         if (e.type == "mouseover") {
  92                                 // set "previous" X and Y position based on initial entry point
  93                                 pX = ev.pageX; pY = ev.pageY;
  94                                 // update "current" X and Y position based on mousemove
  95                                 $(ob).bind("mousemove",track);
  96                                 // start polling interval (self-calling timeout) to compare mouse coordinates over time
  97                                 if (ob.hoverIntent_s != 1) { ob.hoverIntent_t = setTimeout( function(){compare(ev,ob);} , cfg.interval );}
  98
  99                         // else e.type == "onmouseout"
 100                         } else {
 101                                 // unbind expensive mousemove event
 102                                 $(ob).unbind("mousemove",track);
 103                                 // if hoverIntent state is true, then call the mouseOut function after the specified delay
 104                                 if (ob.hoverIntent_s == 1) { ob.hoverIntent_t = setTimeout( function(){delay(ev,ob);} , cfg.timeout );}
 105                         }
 106                 };
 107
 108                 // bind the function to the two event listeners
 109                 return this.mouseover(handleHover).mouseout(handleHover);
 110         };
 111 })(jQuery);