jquery/src/queue.js

(function( jQuery ) {

function handleQueueMarkDefer( elem, type, src ) {
	var deferDataKey = type + "defer",
		queueDataKey = type + "queue",
		markDataKey = type + "mark",
		defer = jQuery.data( elem, deferDataKey, undefined, true );
	if ( defer &&
		( src === "queue" || !jQuery.data( elem, queueDataKey, undefined, true ) ) &&
		( src === "mark" || !jQuery.data( elem, markDataKey, undefined, true ) ) ) {
		// Give room for hard-coded callbacks to fire first
		// and eventually mark/queue something else on the element
		setTimeout( function() {
			if ( !jQuery.data( elem, queueDataKey, undefined, true ) &&
				!jQuery.data( elem, markDataKey, undefined, true ) ) {
				jQuery.removeData( elem, deferDataKey, true );
				defer.resolve();
			}
		}, 0 );
	}
}

jQuery.extend({

	_mark: function( elem, type ) {
		if ( elem ) {
			type = (type || "fx") + "mark";
			jQuery.data( elem, type, (jQuery.data(elem,type,undefined,true) || 0) + 1, true );
		}
	},

	_unmark: function( force, elem, type ) {
		if ( force !== true ) {
			type = elem;
			elem = force;
			force = false;
		}
		if ( elem ) {
			type = type || "fx";
			var key = type + "mark",
				count = force ? 0 : ( (jQuery.data( elem, key, undefined, true) || 1 ) - 1 );
			if ( count ) {
				jQuery.data( elem, key, count, true );
			} else {
				jQuery.removeData( elem, key, true );
				handleQueueMarkDefer( elem, type, "mark" );
			}
		}
	},

	queue: function( elem, type, data ) {
		if ( elem ) {
			type = (type || "fx") + "queue";
			var q = jQuery.data( elem, type, undefined, true );
			// Speed up dequeue by getting out quickly if this is just a lookup
			if ( data ) {
				if ( !q || jQuery.isArray(data) ) {
					q = jQuery.data( elem, type, jQuery.makeArray(data), true );
				} else {
					q.push( data );
				}
			}
			return q || [];
		}
	},

	dequeue: function( elem, type ) {
		type = type || "fx";

		var queue = jQuery.queue( elem, type ),
			fn = queue.shift(),
			defer;

		// If the fx queue is dequeued, always remove the progress sentinel
		if ( fn === "inprogress" ) {
			fn = queue.shift();
		}

		if ( fn ) {
			// Add a progress sentinel to prevent the fx queue from being
			// automatically dequeued
			if ( type === "fx" ) {
				queue.unshift("inprogress");
			}

			fn.call(elem, function() {
				jQuery.dequeue(elem, type);
			});
		}

		if ( !queue.length ) {
			jQuery.removeData( elem, type + "queue", true );
			handleQueueMarkDefer( elem, type, "queue" );
		}
	}
});

jQuery.fn.extend({
	queue: function( type, data ) {
		if ( typeof type !== "string" ) {
			data = type;
			type = "fx";
		}

		if ( data === undefined ) {
			return jQuery.queue( this[0], type );
		}
		return this.each(function() {
			var queue = jQuery.queue( this, type, data );

			if ( type === "fx" && queue[0] !== "inprogress" ) {
				jQuery.dequeue( this, type );
			}
		});
	},
	dequeue: function( type ) {
		return this.each(function() {
			jQuery.dequeue( this, type );
		});
	},
	// Based off of the plugin by Clint Helfers, with permission.
	// http://blindsignals.com/index.php/2009/07/jquery-delay/
	delay: function( time, type ) {
		time = jQuery.fx ? jQuery.fx.speeds[time] || time : time;
		type = type || "fx";

		return this.queue( type, function() {
			var elem = this;
			setTimeout(function() {
				jQuery.dequeue( elem, type );
			}, time );
		});
	},
	clearQueue: function( type ) {
		return this.queue( type || "fx", [] );
	},
	// Get a promise resolved when queues of a certain type
	// are emptied (fx is the type by default)
	promise: function( type, object ) {
		if ( typeof type !== "string" ) {
			object = type;
			type = undefined;
		}
		type = type || "fx";
		var defer = jQuery.Deferred(),
			elements = this,
			i = elements.length,
			count = 1,
			deferDataKey = type + "defer",
			queueDataKey = type + "queue",
			markDataKey = type + "mark";
		function resolve() {
			if ( !( --count ) ) {
				defer.resolveWith( elements, [ elements ] );
			}
		}
		while( i-- ) {
			if (( tmp = jQuery.data( elements[ i ], deferDataKey, undefined, true ) ||
					( jQuery.data( elements[ i ], queueDataKey, undefined, true ) ||
						jQuery.data( elements[ i ], markDataKey, undefined, true ) ) &&
					jQuery.data( elements[ i ], deferDataKey, jQuery._Deferred(), true ) )) {
				count++;
				tmp.done( resolve );
			}
		}
		resolve();
		return defer.promise();
	}
});

})( jQuery );