Club Drupal

// $Id: hoverIntent.js,v 1.1 2010/07/19 22:25:16 danprobo Exp $

(function($){

        /* hoverIntent by Brian Cherne */

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

                // default configuration options

                var cfg = {

                        sensitivity: 7,

                        interval: 100,

                        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);