[效果]JS折叠菜单-moo.fx.js

/*
moo.fx, simple effects library built with prototype.js (http://prototype.conio.net).
by Valerio Proietti (http://mad4milk.net) MIT-style LICENSE.
for more info (http://moofx.mad4milk.net).
Sunday, March 05, 2006
v 1.2.3
*/

var fx = new Object();
//base
fx.Base = function(){};
fx.Base.prototype = {
 setOptions: function(options) {
 this.options = {
  duration: 500,
  onComplete: '',
  transition: fx.sinoidal
 }
 Object.extend(this.options, options || {});
 },

 step: function() {
  var time  = (new Date).getTime();
  if (time >= this.options.duration+this.startTime) {
   this.now = this.to;
   clearInterval (this.timer);
   this.timer = null;
   if (this.options.onComplete) setTimeout(this.options.onComplete.bind(this), 10);
  }
  else {
   var Tpos = (time - this.startTime) / (this.options.duration);
   this.now = this.options.transition(Tpos) * (this.to-this.from) + this.from;
  }
  this.increase();
 },

 custom: function(from, to) {
  if (this.timer != null) return;
  this.from = from;
  this.to = to;
  this.startTime = (new Date).getTime();
  this.timer = setInterval (this.step.bind(this), 13);
 },

 hide: function() {
  this.now = 0;
  this.increase();
 },

 clearTimer: function() {
  clearInterval(this.timer);
  this.timer = null;
 }
}

//stretchers
fx.Layout = Class.create();
fx.Layout.prototype = Object.extend(new fx.Base(), {
 initialize: function(el, options) {
  this.el = $(el);
  this.el.style.overflow = "hidden";
  this.iniWidth = this.el.offsetWidth;
  this.iniHeight = this.el.offsetHeight;
  this.setOptions(options);
 }
});

fx.Height = Class.create();
Object.extend(Object.extend(fx.Height.prototype, fx.Layout.prototype), { 
 increase: function() {
  this.el.style.height = this.now + "px";
 },

 toggle: function() {
  if (this.el.offsetHeight > 0) this.custom(this.el.offsetHeight, 0);
  else this.custom(0, this.el.scrollHeight);
 }
});

fx.Width = Class.create();
Object.extend(Object.extend(fx.Width.prototype, fx.Layout.prototype), { 
 increase: function() {
  this.el.style.width = this.now + "px";
 },

 toggle: function(){
  if (this.el.offsetWidth > 0) this.custom(this.el.offsetWidth, 0);
  else this.custom(0, this.iniWidth);
 }
});

//fader
fx.Opacity = Class.create();
fx.Opacity.prototype = Object.extend(new fx.Base(), {
 initialize: function(el, options) {
  this.el = $(el);
  this.now = 1;
  this.increase();
  this.setOptions(options);
 },

 increase: function() {
  if (this.now == 1 && (/Firefox/.test(navigator.userAgent))) this.now = 0.9999;
  this.setOpacity(this.now);
 },
 
 setOpacity: function(opacity) {
  if (opacity == 0 && this.el.style.visibility != "hidden") this.el.style.visibility = "hidden";
  else if (this.el.style.visibility != "visible") this.el.style.visibility = "visible";
  if (window.ActiveXObject) this.el.style.filter = "alpha(opacity=" + opacity*100 + ")";
  this.el.style.opacity = opacity;
 },

 toggle: function() {
  if (this.now > 0) this.custom(1, 0);
  else this.custom(0, 1);
 }
});

//transitions
fx.sinoidal = function(pos){
 return ((-Math.cos(pos*Math.PI)/2) + 0.5);
 //this transition is from script.aculo.us
}
fx.linear = function(pos){
 return pos;
}
fx.cubic = function(pos){
 return Math.pow(pos, 3);
}
fx.circ = function(pos){
 return Math.sqrt(pos);
}