/*!

 * 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, 2014 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: 6,

            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.sqrt( (pX-cX)*(pX-cX) + (pY-cY)*(pY-cY) ) < cfg.sensitivity ) {

                $(ob).off("mousemove.hoverIntent",track);

                // set hoverIntent state to true (so mouseOut can be called)

                ob.hoverIntent_s = true;

                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 = false;

            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 = $.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) { 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) { 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);