https://setagaya-hifuka.jp/js/bsn.Crossfader.js

1/**
2 *  author:		Timothy Groves - http://www.brandspankingnew.net
3 *	version:	1.3 - 2006-11-02
4 *				1.2 - 2006-11-01
5 *				1.1 - 2006-09-29
6 *				1.0 - 2006-09-25
7 *
8 *	requires:	nothing
9 *
10 */
11
12var useBSNns;
13
14if (useBSNns)
15{
16	if (typeof(bsn) == "undefined")
17		bsn = {}
18	var _bsn = bsn;
19}
20else
21{
22	var _bsn = this;
23}
24
25
26
27
28
29_bsn.Crossfader = function (divs, fadetime, delay )
30{	
31	this.nAct = -1;
32	this.aDivs = divs;
33	
34	for (var i=0;i<divs.length;i++)
35	{
36		document.getElementById(divs[i]).style.opacity = 0;
37		document.getElementById(divs[i]).style.position = "absolute";
38		document.getElementById(divs[i]).style.filter = "alpha(opacity=0)";
39		document.getElementById(divs[i]).style.visibility = "hidden";
40	}
41	
42	this.nDur = fadetime;
43	this.nDelay = delay;
44		
45	this._newfade();
46}
47
48
49_bsn.Crossfader.prototype._newfade = function()
50{
51	if (this.nID1)
52		clearInterval(this.nID1);
53	
54	this.nOldAct = this.nAct;
55	this.nAct++;
56	if (!this.aDivs[this.nAct])	this.nAct = 0;
57	
58	if (this.nAct == this.nOldAct)
59		return false;
60	
61	document.getElementById( this.aDivs[this.nAct] ).style.visibility = "visible";
62	
63	this.nInt = 50;
64	this.nTime = 0;
65	
66	var p=this;
67	this.nID2 = setInterval(function() { p._fade() }, this.nInt);
68}
69
70
71_bsn.Crossfader.prototype._fade = function()
72{
73	this.nTime += this.nInt;
74	
75	var ieop = Math.round( this._easeInOut(this.nTime, 0, 1, this.nDur) * 100 );
76	var op = ieop / 100;
77	document.getElementById( this.aDivs[this.nAct] ).style.opacity = op;
78	document.getElementById( this.aDivs[this.nAct] ).style.filter = "alpha(opacity="+ieop+")";
79	
80	if (this.nOldAct > -1)
81	{
82		document.getElementById( this.aDivs[this.nOldAct] ).style.opacity = 1 - op;
83		document.getElementById( this.aDivs[this.nOldAct] ).style.filter = "alpha(opacity="+(100 - ieop)+")";
84	}
85	
86	if (this.nTime == this.nDur)
87	{
88		clearInterval( this.nID2 );
89		
90		if (this.nOldAct > -1)
91			document.getElementById( this.aDivs[this.nOldAct] ).style.visibility = "hidden";	
92		
93		var p=this;
94		this.nID1 = setInterval(function() { p._newfade() }, this.nDelay);
95	}
96}
97
98
99
100_bsn.Crossfader.prototype._easeInOut = function(t,b,c,d)
101{
102	return c/2 * (1 - Math.cos(Math.PI*t/d)) + b;
103}