source: extensions/EasyCaptcha/template/jquery.events/jquery.event.drop.live-2.2.js @ 24215

/*! 
 * jquery.event.drop.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, event.drop 2.2

;(function($){ // secure $ jQuery alias

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

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

// the namespace for internal live events
drop.livekey = "livedrop";

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

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

// identify potential delegate elements
drop.delegate = function( event, dd ){
        // local refs
        var elems = [], $targets, 
        // element event structure
        events = $.data( this, "events" ) || {};
        // query live events
        $.each( events || [], function( key, arr ){
                // no event type matches
                if ( key.indexOf("drop") !== 0 )
                        return;
                $.each( arr, function( i, obj ){
                        // locate the elements to delegate
                        $targets = $( event.currentTarget ).find( obj.selector );
                        // no element found
                        if ( !$targets.length ) 
                                return;
                        // take each target...
                        $targets.each(function(){
                                // add an event handler
                                $event.add( this, obj.origType +'.'+ drop.livekey, obj.origHandler || obj.handler, obj.data );
                                // remember new elements
                                if ( $.inArray( this, elems ) < 0 )
                                        elems.push( this );     
                        });     
                });
        });
        // may not exist when artifically triggering dropinit event
        if ( dd )
                // clean-up after the interaction ends
                $event.add( dd.drag, "dragend."+drop.livekey, function(){
                        $.each( elems.concat( this ), function(){
                                $event.remove( this, '.'+ drop.livekey );                                                       
                        });
                });
        //drop.delegates.push( elems );
        return elems.length ? $( elems ) : false;
};

})( jQuery );