_Deferred_D.js

jQuery._Deferred = function() {
	var // callbacks list
		callbacks = [],
		// stored [ context , args ]
		fired,
		// to avoid firing when already doing so (or it is halted)
		firing,
		// flag to know if the deferred has been cancelled
		cancelled,
		// the deferred itself
		deferred  = {

			// done( f1, f2, ...)
			done: function() {
				if ( !cancelled ) {
					var args = arguments,
						i,
						length,
						elem,
						type,
						_fired;
						
					if ( fired && !firing ) {
						_fired = fired;
						fired = 0;
					}
					
					for ( i = 0, length = args.length; i < length; i++ ) {
						elem = args[ i ];
						type = jQuery.type( elem );
						if ( type === "array" ) {
							deferred.done.apply( deferred, elem );
						} else if ( type === "function" ) {
							callbacks.push( elem );
						}
					}
					
					if ( _fired ) {
						deferred.resolveWith( _fired[ 0 ], _fired[ 1 ] );
					}
				}
				return this;
			},

			// resolve with given context and args
			resolveWith: function( context, args ) {
				if ( !cancelled && !fired && !firing ) {
					firing = 1;
					fired = [ context, args ];
					
					while( callbacks[ 0 ] ) {
						callbacks.shift().apply( context, args );
					}
					
					firing = 0;
				}
				return this;
			},

			// resolve with this as context and given arguments
			resolve: function() {
				deferred.resolveWith( jQuery.isFunction( this.promise ) ? this.promise() : this, arguments );
				return this;
			},
			
			// Resume resolving (in case it is halted by an exception).
			resume: function() {
				firing = 0;
				deferred.done();
				return this;
			},

			// Has this deferred been resolved?
			isResolved: function() {
				return !!fired;
			},

			// Cancel
			cancel: function() {
				cancelled = 1;
				callbacks = [];
				return this;
			}
		};

	return deferred;
};