queue.unshift(“inprogress”);
}
fn.call(elem, function() {
jQuery.dequeue(elem, type);
});
}
}
});
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( i, elem ) {
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”, [] );
}
});
1.6添加了_mark,_unmark，promise。queue是让函数同属一个队伍里面，目的是让动画一个接一个执行。_mark则是让它们各自拥有队伍，并列执行（虽然它们只记录异步列队中已被执行的函数个数）。promise则在这些并发执行的动画执行后才执行另些一些回调（或动画）。
(function( jQuery ) {
function handleQueueMarkDefer( elem, type, src ) {
//清空记录deferred个数的字段，函数列队与异步列队
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”;//创建一个以mark为后缀的字段，用于记录此列队中个数
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”;
