Realization of seamless scrolling animation based on javascript 2

Achieving the same effect with less code should be the ultimate goal of our program writing, of course, readability cannot be lost. In javascript-based seamless scrolling animation implementation 1 of the last 1 running box, I have done this exploration. However, we still make a fuss about scrollTop/scrollLeft and offsetTop/offsetLeft. The general idea is basically like this, let a certain element move in a certain direction as a whole, so that its contents (pictures or words) will move along, and when the element moves to a certain distance, it will return to the origin. In order to prevent the content from moving away, we need two sets of the same content. In Part 1, the second set of content is dynamically generated and copied to another sibling element, which requires a bit of trouble to arrange all the content horizontally in one when scrolling horizontally. I thought, would it be better to add the second set of contents directly to the same elements? At least CSS also writes 1 point less. There is another drawback to scrolling with scrollTop/scrollLeft, which has strict regulations on the width and height of the parent container. For example, if we want to scroll pictures up and down, ul is the container, and li's pictures are scrolled content, then the height of ul is at least twice the height of the pictures (we assume that the sizes of each picture are equal), otherwise it cannot move. In view of this, I developed a new generation of seamless scrolling functions.

<ul id="marquee">
 <li>
 <a href="http://www.cnblogs.com/rubylouvre/" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" ><img src="o_s017.jpg" alt=" Seamless rolling "/></a>
 <a href="http://www.cnblogs.com/rubylouvre/" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" ><img src="o_s018.jpg" alt=" Seamless rolling "/></a>
 <a href="http://www.cnblogs.com/rubylouvre/" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" ><img src="o_s019.jpg" alt=" Seamless rolling "/></a>
 <a href="http://www.cnblogs.com/rubylouvre/" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" ><img src="o_s020.jpg" alt=" Seamless rolling "/></a>
 <a href="http://www.cnblogs.com/rubylouvre/" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" ><img src="o_s021.jpg" alt=" Seamless rolling "/></a>
 <a href="http://www.cnblogs.com/rubylouvre/" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" ><img src="o_s022.jpg" alt=" Seamless rolling "/></a>
 <a href="http://www.cnblogs.com/rubylouvre/" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" ><img src="o_s023.jpg" alt=" Seamless rolling "/></a>
 </li>
</ul>

#marquee ,#marquee li {
 padding:0;
 margin:0;
}
#marquee {
 position:relative;
 list-style:none;
 height:150px;
 width:200px;
 overflow:hidden;
 border:10px solid #369;
}
#marquee li {
 position:absolute;
}
#marquee img {
 display:block;
 border:0;
}

var Marquee = function(id){
 try{document.execCommand("BackgroundImageCache", false, true);}catch(e){};
 var container = document.getElementById(id),
 slide = container.getElementsByTagName("li")[0],
 speed = arguments[1] || 10,
 delta = 0,// The current scrolling position 
 critical = slide.offsetHeight;// Critical value 
 slide.innerHTML += slide.innerHTML;
 var rolling = function(){
 delta == -critical ? delta = 0 : delta--;
 slide.style.top = delta + "px";
 }
 var timer = setInterval(rolling,speed)// Set the timer 
 container.onmouseover=function() {clearInterval(timer)}// Move the mouse to marquee Clear the timer and stop scrolling 
 container.onmouseout=function() {timer=setInterval(rolling,speed)}// Reset the timer when the mouse moves away 
}
window.onload = function(){
 Marquee("marquee");
}

 
<!doctype html>
<title>javascript Seamless rolling  by  Situ Masami </title>
<meta charset="utf-8"/>
<meta name="keywords" content="javascript Seamless rolling  by  Situ Masami " />
<meta name="description" content="javascript Seamless rolling  by  Situ Masami " />
<base href="http://images.cnblogs.com/cnblogs_com/rubylouvre/199042/" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" >
<style type="text/css">
 h1 {
 font:400 16px/1 "Microsoft YaHei",KaiTi_GB2312,SimSun
 }
 #marquee ,#marquee li {
 padding:0;
 margin:0;
 }
 #marquee {
 position:relative;
 list-style:none;
 height:150px;
 width:200px;
 overflow:hidden;
 border:10px solid #369;
 }
 #marquee li {
 position:absolute;
 }
 #marquee img {
 display:block;
 border:0;
 }
</style>
<script type="text/javascript">
 var Marquee = function(id){
 try{document.execCommand("BackgroundImageCache", false, true);}catch(e){};
 var container = document.getElementById(id),
 slide = container.getElementsByTagName("li")[0],
 speed = arguments[1] || 10,
 delta = 0,// The current scrolling position 
 critical = slide.offsetHeight;// Critical point 
 slide.innerHTML += slide.innerHTML;
 var rolling = function(){
  delta == -critical ? delta = 0 : delta--;
  slide.style.top = delta + "px";
 }
 var timer = setInterval(rolling,speed)// Set the timer 
 container.onmouseover=function() {clearInterval(timer)}// Move the mouse to marquee Clear the timer and stop scrolling 
 container.onmouseout=function() {timer=setInterval(rolling,speed)}// Reset the timer when the mouse moves away 
 }
 window.onload = function(){
 Marquee("marquee");
 }
</script>
<h1>javascript Seamless rolling ( Scroll up ) by  Situ Masami </h1>
<base href="http://images.cnblogs.com/cnblogs_com/rubylouvre/199042/" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" >
<ul id="marquee">
 <li>
 <a href="http://www.cnblogs.com/rubylouvre/" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" ><img src="o_s017.jpg" alt=" Seamless rolling  by  Situ Masami "/></a>
 <a href="http://www.cnblogs.com/rubylouvre/" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" ><img src="o_s018.jpg" alt=" Seamless rolling  by  Situ Masami "/></a>
 <a href="http://www.cnblogs.com/rubylouvre/" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" ><img src="o_s019.jpg" alt=" Seamless rolling  by  Situ Masami "/></a>
 <a href="http://www.cnblogs.com/rubylouvre/" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" ><img src="o_s020.jpg" alt=" Seamless rolling  by  Situ Masami "/></a>
 <a href="http://www.cnblogs.com/rubylouvre/" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" ><img src="o_s021.jpg" alt=" Seamless rolling  by  Situ Masami "/></a>
 <a href="http://www.cnblogs.com/rubylouvre/" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" ><img src="o_s022.jpg" alt=" Seamless rolling  by  Situ Masami "/></a>
 <a href="http://www.cnblogs.com/rubylouvre/" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" ><img src="o_s023.jpg" alt=" Seamless rolling  by  Situ Masami "/></a>
 </li>
</ul>

It's also easy to scroll down, except that 1 starts to position it between the first set of content and the second set of content, that is, slide. offsetHeight, but we need to change it to a negative number to move it down to the whole, and then move it up slowly.

 
<!doctype html>
<title>javascript Seamless rolling  by  Situ Masami </title>
<meta charset="utf-8"/>
<meta name="keywords" content="javascript Seamless rolling  by  Situ Masami " />
<meta name="description" content="javascript Seamless rolling  by  Situ Masami " />
<base href="http://images.cnblogs.com/cnblogs_com/rubylouvre/199042/" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" >
<style type="text/css">
 h1 {
 font:400 16px/1 "Microsoft YaHei",KaiTi_GB2312,SimSun
 }
 #marquee ,#marquee li {
 padding:0;
 margin:0;
 }
 #marquee {
 position:relative;
 list-style:none;
 height:150px;
 width:200px;
 overflow:hidden;
 border:10px solid #B45B3E;
 }
 #marquee li {
 position:absolute;
 }
 #marquee img {
 display:block;
 border:0;
 }
</style>
<script type="text/javascript">
 var Marquee = function(id){
 try{document.execCommand("BackgroundImageCache", false, true);}catch(e){};
 var container = document.getElementById(id),
 slide = container.getElementsByTagName("li")[0],
 speed = arguments[1] || 10,
 critical = slide.offsetHeight,// Critical value 
 delta = -critical;
 slide.innerHTML += slide.innerHTML;
 var rolling = function(){
  delta == 0 ? delta = -critical : delta++;
  slide.style.top = delta + "px";
 }
 var timer = setInterval(rolling,speed)// Set the timer 
 container.onmouseover=function() {clearInterval(timer)}// Move the mouse to marquee Clear the timer and stop scrolling 
 container.onmouseout=function() {timer=setInterval(rolling,speed)}// Reset the timer when the mouse moves away 
 }
 window.onload = function(){
 Marquee("marquee");
 }
</script>
<h1>javascript Seamless rolling ( Scroll down ) by  Situ Masami </h1>
<base href="http://images.cnblogs.com/cnblogs_com/rubylouvre/199042/" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" >
<ul id="marquee">
 <li>
 <a href="http://www.cnblogs.com/rubylouvre/" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" ><img src="o_s017.jpg" alt=" Seamless rolling "/></a>
 <a href="http://www.cnblogs.com/rubylouvre/" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" ><img src="o_s018.jpg" alt=" Seamless rolling "/></a>
 <a href="http://www.cnblogs.com/rubylouvre/" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" ><img src="o_s019.jpg" alt=" Seamless rolling "/></a>
 <a href="http://www.cnblogs.com/rubylouvre/" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" ><img src="o_s020.jpg" alt=" Seamless rolling "/></a>
 <a href="http://www.cnblogs.com/rubylouvre/" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" ><img src="o_s021.jpg" alt=" Seamless rolling "/></a>
 <a href="http://www.cnblogs.com/rubylouvre/" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" ><img src="o_s022.jpg" alt=" Seamless rolling "/></a>
 <a href="http://www.cnblogs.com/rubylouvre/" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" ><img src="o_s023.jpg" alt=" Seamless rolling "/></a>
 </li>
</ul>

It is also easier to achieve horizontal movement than in Part 1, with no changes to the structure layer and few changes to the presentation layer.

#marquee ,#marquee li {
 padding:0;
 margin:0;
}
#marquee {
 position:relative;
 list-style:none;
 height:150px;
 width:200px;
 overflow:hidden;
 border:10px solid #B45B3E;
}
#marquee li {
 position:absolute;
 width:1000%;/* ★ ★ newly added ★ ★ */
}
#marquee a {
 float:left;/* ★ ★ newly added ★ ★ */
}
#marquee img {
 display:block;
 border:0;
}

The difficulty is how to get that critical value, that is, the position sandwiched between the first set of content and the second set of content. Since we don't have an element in the second set, we need to start with scrolling objects. Scroll objects are all a elements, so we need to calculate the distance from the first a element in the second set to the left of the parent element. This value is the critical value we require. Understand this, and it will be easy.

 //************* Slightly ********* 
 slide.innerHTML += slide.innerHTML;
 var item = slide.getElementsByTagName("a"),
 critical = item[item.length/2].offsetLeft,// Critical value 
//************* Slightly ********* 

 
<!doctype html>
<title>javascript Seamless rolling  by  Situ Masami </title>
<meta charset="utf-8"/>
<meta name="keywords" content="javascript Seamless rolling  by  Situ Masami " />
<meta name="description" content="javascript Seamless rolling  by  Situ Masami " />
<base href="http://images.cnblogs.com/cnblogs_com/rubylouvre/199042/" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" >
<style type="text/css">
 h1 {
 font:400 16px/1 "Microsoft YaHei",KaiTi_GB2312,SimSun
 }
 #marquee ,#marquee li {
 padding:0;
 margin:0;
 }
 #marquee {
 position:relative;
 list-style:none;
 height:150px;
 width:200px;
 overflow:hidden;
 border:10px solid #8080C0;
 }
 #marquee li {
 position:absolute;
 width:1000%;/* New additions */
 }
 #marquee a {
 float:left;/* New additions */
 }
 #marquee img {
 display:block;
 border:0;
 }
</style>
<script type="text/javascript">
 var Marquee = function(id){
 try{document.execCommand("BackgroundImageCache", false, true);}catch(e){};
 var container = document.getElementById(id),
 slide = container.getElementsByTagName("li")[0],
 speed = arguments[1] || 10;
 slide.innerHTML += slide.innerHTML;
 var item = slide.getElementsByTagName("a"),
 critical = item[item.length/2].offsetLeft,// Critical value 
 delta = 0;
 var rolling = function(){
  delta == -critical ? delta = 0 : delta--;
  slide.style.left = delta + "px";
 }
 var timer = setInterval(rolling,speed)// Set the timer 
 container.onmouseover=function() {clearInterval(timer)}// Move the mouse to marquee Clear the timer and stop scrolling 
 container.onmouseout=function() {timer=setInterval(rolling,speed)}// Reset the timer when the mouse moves away 
 }
 window.onload = function(){
 Marquee("marquee");
 }
</script>
<h1>javascript Seamless rolling ( Scroll to the left ) by  Situ Masami </h1>
<base href="http://images.cnblogs.com/cnblogs_com/rubylouvre/199042/" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" >
<ul id="marquee">
 <li>
 <a href="http://www.cnblogs.com/rubylouvre/" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" ><img src="o_s017.jpg" alt=" Seamless rolling "/></a>
 <a href="http://www.cnblogs.com/rubylouvre/" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" ><img src="o_s018.jpg" alt=" Seamless rolling "/></a>
 <a href="http://www.cnblogs.com/rubylouvre/" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" ><img src="o_s019.jpg" alt=" Seamless rolling "/></a>
 <a href="http://www.cnblogs.com/rubylouvre/" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" ><img src="o_s020.jpg" alt=" Seamless rolling "/></a>
 <a href="http://www.cnblogs.com/rubylouvre/" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" ><img src="o_s021.jpg" alt=" Seamless rolling "/></a>
 <a href="http://www.cnblogs.com/rubylouvre/" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" ><img src="o_s022.jpg" alt=" Seamless rolling "/></a>
 <a href="http://www.cnblogs.com/rubylouvre/" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" ><img src="o_s023.jpg" alt=" Seamless rolling "/></a>
 </li>
</ul>

The following is scrolling to the right, because are less than 20 lines of scripts, should see the source code to understand, not detailed.

 
<!doctype html>
<title>javascript Seamless rolling  by  Situ Masami </title>
<meta charset="utf-8"/>
<meta name="keywords" content="javascript Seamless rolling  by  Situ Masami " />
<meta name="description" content="javascript Seamless rolling  by  Situ Masami " />
<base href="http://images.cnblogs.com/cnblogs_com/rubylouvre/199042/" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" >
<style type="text/css">
 h1 {
 font:400 16px/1 "Microsoft YaHei",KaiTi_GB2312,SimSun
 }
 #marquee ,#marquee li {
 padding:0;
 margin:0;
 }
 #marquee {
 position:relative;
 list-style:none;
 height:150px;
 width:200px;
 overflow:hidden;
 border:10px solid #6cc;
 }
 #marquee li {
 position:absolute;
 width:1000%;
 }
 #marquee a {
 float:left;
 }
 #marquee img {
 display:block;
 border:0;
 }
</style>
<script type="text/javascript">
 var Marquee = function(id){
 try{document.execCommand("BackgroundImageCache", false, true);}catch(e){};
 var container = document.getElementById(id),
 slide = container.getElementsByTagName("li")[0],
 speed = arguments[1] || 10;
 slide.innerHTML += slide.innerHTML;
 var item = slide.getElementsByTagName("a"),// Critical point 
 critical = item[item.length/2].offsetLeft,
 delta = -critical;
 var rolling = function(){
  delta == 0 ? delta = -critical : delta++;
  slide.style.left = delta + "px";
 }
 var timer = setInterval(rolling,speed)// Set the timer 
 container.onmouseover=function() {clearInterval(timer)}// Move the mouse to marquee Clear the timer and stop scrolling 
 container.onmouseout=function() {timer=setInterval(rolling,speed)}// Reset the timer when the mouse moves away 
 }
 window.onload = function(){
 Marquee("marquee");
 }
</script>
<h1>javascript Seamless rolling ( Scroll to the right ) by  Situ Masami </h1>
<base href="http://images.cnblogs.com/cnblogs_com/rubylouvre/199042/" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" >
<ul id="marquee">
 <li>
 <a href="http://www.cnblogs.com/rubylouvre/" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" ><img src="o_s017.jpg" alt=" Seamless rolling "/></a>
 <a href="http://www.cnblogs.com/rubylouvre/" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" ><img src="o_s018.jpg" alt=" Seamless rolling "/></a>
 <a href="http://www.cnblogs.com/rubylouvre/" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" ><img src="o_s019.jpg" alt=" Seamless rolling "/></a>
 <a href="http://www.cnblogs.com/rubylouvre/" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" ><img src="o_s020.jpg" alt=" Seamless rolling "/></a>
 <a href="http://www.cnblogs.com/rubylouvre/" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" ><img src="o_s021.jpg" alt=" Seamless rolling "/></a>
 <a href="http://www.cnblogs.com/rubylouvre/" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" ><img src="o_s022.jpg" alt=" Seamless rolling "/></a>
 <a href="http://www.cnblogs.com/rubylouvre/" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" ><img src="o_s023.jpg" alt=" Seamless rolling "/></a>
 </li>
</ul>

We can combine the above four functions into one function, and the structure layer and presentation layer scroll up with reference.

var Marquee = function(id){
 try{document.execCommand("BackgroundImageCache", false, true);}catch(e){};
 var container = document.getElementById(id),
 slide = container.getElementsByTagName("li")[0],
 options = arguments[1] || {},
 speed = options.speed || 10,
 direction = options.direction || "left";
 slide.innerHTML += slide.innerHTML;
 var item = slide.getElementsByTagName("a"),
 critical,delta,rolling,field;
 if(direction == "left" || direction == "right"){
 slide.style.cssText = "width:1000%";
 for(var i=0 ,l=item.length; i<l;i++){
  item[i].style.cssText = "float:left";
 }
 field = "left";
 critical = item[item.length/2].offsetLeft;
 }else if(direction == "up" || direction == "down"){
 field = "top";
 critical = item[item.length/2].offsetTop;
 }
 if(direction == "up" || direction == "left"){
 delta = 0;
 rolling = function(){
  delta == -critical ? delta = 0 : delta--;
  slide.style[field] = delta + "px";
 }
 }else if(direction == "down" || direction == "right"){
 delta = -critical;
 rolling = function(){
  delta == 0 ? delta = -critical : delta++;
  slide.style[field] = delta + "px";
 }
 }
 var timer = setInterval(rolling,speed)// Set the timer 
 container.onmouseover=function() {clearInterval(timer)}// Move the mouse to marquee Clear the timer and stop scrolling 
 container.onmouseout=function() {timer=setInterval(rolling,speed)}// Reset the timer when the mouse moves away 
}

Use:

#marquee ,#marquee li {
 padding:0;
 margin:0;
}
#marquee {
 position:relative;
 list-style:none;
 height:150px;
 width:200px;
 overflow:hidden;
 border:10px solid #369;
}
#marquee li {
 position:absolute;
}
#marquee img {
 display:block;
 border:0;
}

0

With this, it is easy for us to realize another kind of picture rotation. Let's make a preview first. This article ends here.