javascript实现连续滚动[摇摇欲堕(王勇帅)Blog]

<script language="JavaScript" defer>
//qswh's original and modifid by windy_sk <windy_sk@126.com> 20040120

function reportError(msg,url,line) {
var str = "You have found an error as below: nn";
str += "Err: " + msg + " on line: " + line;
alert(str);
return true;
}

window.onerror = reportError;

var obj_marquee = document.getElementById("marquee");
var repeat = null;
var marquee_spd = 50;

function marquee_init() {
var obj_unit = obj_marquee.firstChild;
var marquee_high = parseInt(obj_marquee.style.height);
var marquee_wide = parseInt(obj_marquee.style.width);
var unit_high = obj_unit.offsetHeight;
var unit_wide = obj_unit.offsetWidth;
var m = 0, n = 0, i = 0;
var tmp = null;

m = Math.ceil(marquee_wide / unit_wide);
n = Math.ceil(marquee_high / unit_high);

obj_unit.style.width = marquee_wide * (m+1);
obj_unit.rows[0].cells[0].style.width = obj_marquee.style.width;

for(i=0; i<m; i++) {
   tmp = obj_unit.rows[0].insertCell(-1);
   tmp.innerHTML = obj_unit.rows[0].cells[0].innerHTML;
   tmp.style.width = marquee_wide;
   tmp = null;
}

for(i=0; i<n; i++) {
   obj_marquee.appendChild(obj_unit.cloneNode(true));
}

return;
}

function marquee_show(direction) {
switch(direction) {
   case "up":
    if(obj_marquee.scrollTop >= obj_marquee.children[1].offsetTop) {
     obj_marquee.scrollTop -= obj_marquee.firstChild.offsetHeight;
    } else {
     obj_marquee.scrollTop++;
    }
    break;
   case "down":
    if(obj_marquee.scrollTop <= 0) {
     obj_marquee.scrollTop += obj_marquee.firstChild.offsetHeight;
    } else {
     obj_marquee.scrollTop--;
    }
    break;
   case "left":
    if(obj_marquee.scrollLeft >= obj_marquee.firstChild.rows[0].cells[0].offsetWidth) {
     obj_marquee.scrollLeft -= obj_marquee.firstChild.rows[0].cells[0].offsetWidth;
    } else {
     obj_marquee.scrollLeft++;
    }
    break;
   case "right":
    if(obj_marquee.scrollLeft <= 0) {
     obj_marquee.scrollLeft += obj_marquee.firstChild.rows[0].cells[0].offsetWidth;
    } else {
     obj_marquee.scrollLeft--;
    }
    break;
   default:
    break;
}
return;
}

function marquee_doit() {
var direction = "";
direction = obj_marquee.getAttribute("direction");
if(direction != null) marquee_show(direction);
direction = obj_marquee.getAttribute("direction2");
if(direction != null) marquee_show(direction);
return;
}

marquee_init();
repeat = setInterval("marquee_doit()",marquee_spd);

marquee.onmouseover = function() {clearInterval(repeat);}
marquee.onmouseout = function() {repeat=setInterval("marquee_doit()",marquee_spd);}
</script>

<table style="border:1px black solid;"><tr><td>
<div id="marquee" direction="up" style="overflow:hidden;height:200px;width:250px">
   <table style="border:0px;padding:0px;"><tr><td>
     <!-- Marquee Body Head -->
     <a href="#" target="_blank">经典论坛</a><br>
     <a href="#" target="_blank">163.com</a><br>
     <a href="#" target="_blank">21cn.com</a><br>
     <a href="#" target="_blank">Happy new year</a>
     <!-- Marquee Body Bottom -->
   </td></tr></table>
</div>
</td></tr></table>

Direction1:
<input type="button" value="↑" onclick="obj_marquee.direction='up'">
<input type="button" value="↓" onclick="obj_marquee.direction='down'">
<input type="button" value="←" onclick="obj_marquee.direction='left'">
<input type="button" value="→" onclick="obj_marquee.direction='right'">
<input type="button" value=" X " onclick="obj_marquee.direction=''"> <br>

Direction2:
<input type="button" value="↑" onclick="obj_marquee.direction2='up'">
<input type="button" value="↓" onclick="obj_marquee.direction2='down'">
<input type="button" value="←" onclick="obj_marquee.direction2='left'">
<input type="button" value="→" onclick="obj_marquee.direction2='right'">
<input type="button" value=" X " onclick="obj_marquee.direction2=''">