source: extensions/EasyCaptcha/template/jquery.events/jquery.event.drag.live-2.2.js @ 25219

/*! 
 * jquery.event.drag.live - v 2.2
 * Copyright (c) 2010 Three Dub Media - http://threedubmedia.com
 * Open Source MIT License - http://threedubmedia.com/code/license
 */
// Created: 2010-06-07
// Updated: 2012-05-21
// REQUIRES: jquery 1.7.x, event.drag 2.2

;(function( $ ){
        
// local refs (increase compression)
var $event = $.event,
// ref the special event config
drag = $event.special.drag,
// old drag event add method
origadd = drag.add,
// old drag event teradown method
origteardown = drag.teardown;

// allow events to bubble for delegation
drag.noBubble = false;

// the namespace for internal live events
drag.livekey = "livedrag";

// new drop event add method
drag.add = function( obj ){ 
        // call the old method
        origadd.apply( this, arguments );
        // read the data
        var data = $.data( this, drag.datakey );
        // bind the live "draginit" delegator
        if ( !data.live && obj.selector ){
                data.live = true;
                $event.add( this, "draginit."+ drag.livekey, drag.delegate );
        }
};

// new drop event teardown method
drag.teardown = function(){ 
        // call the old method
        origteardown.apply( this, arguments );
        // read the data
        var data = $.data( this, drag.datakey ) || {};
        // bind the live "draginit" delegator
        if ( data.live ){
                // remove the "live" delegation
                $event.remove( this, "draginit."+ drag.livekey, drag.delegate );
                data.live = false;
        }
};

// identify potential delegate elements
drag.delegate = function( event ){
        // local refs
        var elems = [], target, 
        // element event structure
        events = $.data( this, "events" ) || {};
        // query live events
        $.each( events || [], function( key, arr ){
                // no event type matches
                if ( key.indexOf("drag") !== 0 )
                        return;
                $.each( arr || [], function( i, obj ){
                        // locate the element to delegate
                        target = $( event.target ).closest( obj.selector, event.currentTarget )[0];
                        // no element found
                        if ( !target ) 
                                return;
                        // add an event handler
                        $event.add( target, obj.origType+'.'+drag.livekey, obj.origHandler || obj.handler, obj.data );
                        // remember new elements
                        if ( $.inArray( target, elems ) < 0 )
                                elems.push( target );           
                });
        });
        // if there are no elements, break
        if ( !elems.length ) 
                return false;
        // return the matched results, and clenup when complete         
        return $( elems ).bind("dragend."+ drag.livekey, function(){
                $event.remove( this, "."+ drag.livekey ); // cleanup delegation
        });
};
        
})( jQuery );