jquery.specialevent.hammer.js

/*
 * special event API with Hammer.JS
 * version 0.9
 * author: Damien Antipa
 * https://github.com/dantipa/hammer.js
 */
(function ($) {
    var hammerEvents = ['hold','tap','doubletap','transformstart','transform','transformend','dragstart','drag','dragend','swipe','release'];

    /*
     * HammerSEFunctions
     * maintains which function should be used to handle
     * events.
     * 
     * _fn : is the original function used to handle events.
     *  Faster than _delegateFn, but it does not support delegated
     *  or bubbled events through jQuery.
     *
     * _delegateFn : a function that supports delegated/bubbled events
     *  in jQuery, but it is slower than _fn as it doesn't use a cached
     *  jQuery call ($target) to trigger from and must construct a new
     *  jQuery object based on the event target each time the event triggers.
     *
     * addDelegate : adds the handler guid created by jQuery to _delegateGuids.
     *
     * removeDelegate : removes the handler guid (if found) in _delegateGuids.
     *
     * getFn : returns either _fn or _delegateFn based on there being any handler
     *  guids saved in _delegateGuids. If there are no guids saved, then the faster
     *  function (_fn) is used. Otherwise, _delegateFn must be used and will be
     *  returned.
     *
     * destroy : destroys all dynamically generated properties in the object. This
     *  may be overkill, but it will help to reduce the chances of any sneaky
     *  memory leaks cropping up.
     */

    function HammerSEFunctions(/*event,$target*/){
        var event = arguments[0],
            $target = arguments[1];

        this._delegateGuids = [];

        this._fn = function(ev){
            
            $target.trigger($.Event(event,ev));
        
        };

        this._delegateFn = function(ev){
            var jqevt = $.Event(event,ev);
            
            $(jqevt.originalEvent.target).trigger(jqevt);
        
        };
    }
    HammerSEFunctions.prototype = {

        addDelegate : function(guid){
            
            this._delegateGuids.push(guid);
            return this;
        
        },

        removeDelegate : function(guid){
            var index = this._delegateGuids.indexOf(guid);
            
            if(index >= 0){
                
                this._delegateGuids.splice(index);
            
            }
            
            return this;
        },

        getFn : function(){
            
            return this._delegateGuids.length > 0 ? this._delegateFn : this._fn;
        
        },

        destroy : function(){
            
            this._fn = null;
            this._delegateFn = null;
            this._delegateGuids = null;
            
            delete this._fn;
            delete this._delegateFn;
            delete this._delegateGuids;
        
        }

    };

    $.each(hammerEvents, function(i, event) {

        $.event.special[event] = {

            setup: function(data, namespaces, eventHandle) {
                var $target = $(this),
                    hammer = $target.data('hammerjs');
                
                if (!hammer) {
                    hammer = new Hammer(this, data);
                    hammer.__Fns = {};
                    $target.data('hammerjs', hammer);
                }

                hammer.__Fns[event] = new HammerSEFunctions(event,$target);
            },
            add : function(handleObj) {
                var hammer = $(this).data('hammerjs');

                if (!!handleObj.selector) {
                    hammer.__Fns[event].addDelegate(handleObj.guid);
                }

                hammer['on' + event] = hammer.__Fns[event].getFn();
            },
            remove : function(handleObj) {
                var hammer = $(this).data('hammerjs');

                if (!!handleObj.selector) {
                    hammer.__Fns[event].removeDelegate(handleObj.guid);
                }

                hammer['on' + event] = hammer.__Fns[event].getFn();
            },
            teardown: function(namespaces) {
                var hammer = $(this).data('hammerjs');

                hammer.__Fns[event].destroy();
                delete hammer.__Fns[event];
            }
        };
    });
}(jQuery));