/**

* hoverIntent is similar to jQuery's built-in "hover" function except that

* instead of firing the onMouseOver event immediately, hoverIntent checks

* to see if the user's mouse has slowed down (beneath the sensitivity

* threshold) before firing the onMouseOver event.

* 

* hoverIntent r5 // 2007.03.27 // jQuery 1.1.2+

* <http://cherne.net/brian/resources/jquery.hoverIntent.html>

* 

* hoverIntent is currently available for use in all personal or commercial 

* projects under both MIT and GPL licenses. This means that you can choose 

* the license that best suits your project, and use it accordingly.

* 

* // basic usage (just like .hover) receives onMouseOver and onMouseOut functions

* $("ul li").hoverIntent( showNav , hideNav );

* 

* // advanced usage receives configuration object only

* $("ul li").hoverIntent({

*   sensitivity: 7, // number = sensitivity threshold (must be 1 or higher)

*   interval: 100,   // number = milliseconds of polling interval

*   over: showNav,  // function = onMouseOver callback (required)

*   timeout: 0,   // number = milliseconds delay before onMouseOut function call

*   out: hideNav    // function = onMouseOut callback (required)

* });

* 

* @param  f  onMouseOver function || An object with configuration options

* @param  g  onMouseOut function  || Nothing (use configuration options object)

* @author    Brian Cherne <brian@cherne.net>

*/

(function($) {

    $.fn.hoverIntent = function(f,g) {

        // default configuration options

        var cfg = {

            sensitivity: 7,

            interval: 200,

            timeout: 0

        };

        // override configuration options with user supplied object

        cfg = $.extend(cfg, g ? { over: f, out: g } : f );



        // 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).unbind("mousemove",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) {

            // next three lines copied from jQuery.hover, ignore children onMouseOver/onMouseOut

            var p = (e.type == "mouseover" ? e.fromElement : e.toElement) || e.relatedTarget;

            while ( p && p != this ) { try { p = p.parentNode; } catch(e) { p = this; } }

            if ( p == this ) { return false; }



            // 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); }



            // else e.type == "onmouseover"

            if (e.type == "mouseover") {

                // 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).bind("mousemove",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 == "onmouseout"

            } else {

                // unbind expensive mousemove event

                $(ob).unbind("mousemove",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 );}

            }

        };



        // bind the function to the two event listeners

        return this.mouseover(handleHover).mouseout(handleHover);

    };

})(jQuery);