﻿function setFocus(ID,t){//主函数...
function $(id) {return document.getElementById(id);}
function $$(tag,obj){return (typeof obj=='object'?obj:$(obj)).getElementsByTagName(tag);}
var n='';//标记
function showPics(num){
	if(n===num) return true;
	if(n==='') n=0;
	else n=num;
	var pics=$$('ul',ID)[0];
	var tit=$$('div',pics)[num];
	if (!pics.style.left){pics.style.left = 0+'px';}
    if (!tit.style.bottom||parseInt(tit.style.bottom)>-34){tit.style.bottom = -34+'px';}
	var endX=-num*$$('div',ID)[0].clientWidth;
	var goimg=function(){
		X=parseInt(pics.style.left);
		if (pics.movement){clearTimeout(pics.movement);}
		if(parseInt(pics.style.left)==endX) return true;
		if((endX-X)>0) X+=Math.ceil((endX-X) / 10);
		else X+=Math.floor((endX-X) / 10);
		pics.style.left=X+'px';
		pics.movement = setTimeout(goimg, 5);
	}
	var gotit=function(){
		var y=parseInt(tit.style.bottom);
		if (tit.movement){clearTimeout(tit.movement);}
		if(y==0) return true;
		y+=Math.ceil((0-y) / 10);
		if(parseInt(pics.style.left)==endX) tit.style.bottom=y+'px';
		if(y<0) tit.movement = setTimeout(gotit, 16);
	}
	goimg();
	gotit();
}
function classNormal() {//数字标签样式清除
    var focusBtnList = $$('li',$$('ul',ID)[1]);
    for (var i = 0; i < focusBtnList.length; i++) {
        focusBtnList[i].className = '';
    }
}
function focusChange() {//交互切换
    var focusBtnList = $$('li',$$('ul',ID)[1]);
    for (var i = 0; i < focusBtnList.length; i++) {
		focusBtnList[i].I=i;
		focusBtnList[i].onmouseover = function(){
        	showPics(this.I);
        	classNormal();
        	focusBtnList[this.I].className = 'current';
		}
	}
}
var autoFocusChange=function() {//自动运行
    if (atuokey) return;
    var focusBtnList = $$('li',$$('ul',ID)[1]);
    for (var i = 0; i < focusBtnList.length; i++) {
        if (focusBtnList[i].className == 'current') {
            var currentNum = i;
        }
    }
	if(currentNum<focusBtnList.length-1){
		showPics(currentNum+1);
       	classNormal();
       	focusBtnList[currentNum+1].className = 'current';
	}else if(currentNum==focusBtnList.length-1){
		showPics(0);
       	classNormal();
       	focusBtnList[0].className = 'current';
	}
}
var atuokey = '';
function init(){//初始化<div><span></span><a href="#">文字说明</a></div>
	var ul=$$('ul',ID)[0];
	var li=$$('li',ul);
	var NUM=li.length;
	var wid=$('myloading')?$$('div',ID)[1].clientWidth:$$('div',ID)[0].clientWidth;ul.style.width=wid*NUM+'px';
	for(var i=0;i<NUM;i++){
		var a=li[i].getElementsByTagName('a')[0];
		var img=li[i].getElementsByTagName('img')[0];
		li[i].innerHTML=li[i].innerHTML+'<div><span></span><a href="'+a+'">'+img.alt+'</a></div>';
	}
	var s='<div class="mybtn"><ul>';
	for(var i=0;i<NUM;i++){s+='<li></li>'}
	s+='</ul></div>';
	$(ID).innerHTML+=s;
	$(ID).removeChild($('myloading'));
	showPics(0);
    classNormal();
    $$('li',$$('ul',ID)[1])[0].className = 'current';
	$(ID).onmouseover = function() {
        atuokey = true;
		clearInterval(auto);
    }
    $(ID).onmouseout = function() {
        atuokey = false;
		auto=setInterval(autoFocusChange, T);
    }
}
var T=t*1000;//每帧图片停留的时间，1000=1秒
var auto='';
init();
focusChange();
auto=setInterval(autoFocusChange, T);
};
window.onload=function myfocus(){
	setFocus('myfocus',4);
}
