Text Scroller: scrolling stops in Firefox

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Mickey - 30 Jul 2005 09:17 GMT

Hi,

I have a script which works in both IE but is sluggish in Firefox.
The script is a simple text scroller.
It works perfectly in IE however in Firefox, the text scroll slower and
eventually just stops.

I would aprechiate it someone could look at the code below and maybe
see where the problem is?

Thank you in advance,
Micky

/*********************************************************************/
<html>
<head>
<title>test</title>

<head></head>
<BODY >

<table bgcolor="00000" width="752" cellpadding="0" cellspacing="0"
border="0">

<tr>
<td>

<SCRIPT>

var text=new Array()
text[0]="testtesttest"
text[1]=" testtest test test test "
text[2]=" testtest test test test"

// Add a link for each message
var textlink=new Array()
textlink[0]="http://"
textlink[1]="http://"
textlink[2]="http://"

// Add a target for each link
// Possible values are "_blank", "_self", "_top", "_parent"
var texttarget=new Array()
texttarget[0]="_blank"
texttarget[1]="_blank"
texttarget[2]="_blank"

...........
var translayersmax=Math.floor(translayerszone/translayerswidth)
var translayersleftpos=0
var translayersopacity=100
var translayersfactor=100/translayersmax
var translayerswidthall=translayersmax*translayerswidth
var ie=document.all?1:0
var ns6=document.getElementById&&!document.all?1:0
var ns4=document.layers?1:0
var browserinfos=navigator.userAgent
var opera=browserinfos.match(/Opera/)

getcontent()
function getcontent() {
    ...

if (ie || ns6) {
    document.write('<table cellpadding=0 cellspacing=0 border=0
        height='+textheight+' width='+textwidth+'><tr><td>');
    document.write('<div id="marker" style="position:relative;
width:'+textwidth+';
        height:'+textheight+'" ></div>');
    document.write('</td></tr></table>')
    if (ns6) {
        var tablewidth=textwidth-2*textborder
        var tableheight=textheight-2*textborder
    }
    else {
        var tablewidth=textwidth
        var tableheight=textheight
    }
    document.write('<div ID="roof" style="position:absolute;width:'
        +tablewidth+'px;height:'+tableheight+'px;border-style:solid;border-width:'+
        textborder+'px;border-color:'+textbordercolor+';background-color:'+textbgcolor+';
        visibility:hidden;overflow:hidden" onMouseOver="setscrollready(0)"
onMouseOut="setscrollready(1)">')
    document.write('<span ID="ticker"
style="position:absolute;top:0px;left:0px;visibility:hidden">'+content+'</span>')

    if (ie && !opera) {
        for (i=0;i<=translayersmax;i++) {
        document.write('<span ID="trans'+i+'"
style="position:absolute;top:0px;left:'+translayersleftpos+'px;width:'+
        translayerswidth+'px;height:'+tableheight+'px;background-color:'+textbgcolor+';filter:alpha(opacity='
        +translayersopacity+');overflow:hidden"> </span>')
        translayersleftpos+=translayerswidth
        translayersopacity-=translayersfactor
        }
        translayersleftpos=tablewidth-translayersleftpos

        for (ii=0;ii<=translayersmax;ii++) {
            document.write('<span ID="trans'+ii+'"
style="position:absolute;top:0px;left:'
            +translayersleftpos+'px;width:'+translayerswidth+'px;height:'+tableheight+'px;background-color:'+
            textbgcolor+';filter:alpha(opacity='+translayersopacity+');overflow:hidden">
</span>')
            translayersleftpos+=translayerswidth
            translayersopacity+=translayersfactor
        }
    }

    if (ns6 && !opera) {
        for (i=0;i<=translayersmax-1;i++) {
        document.write('<span ID="transleft'+i+'"
style="position:absolute;top:0px;left:'+
        translayersleftpos+'px;width:'+translayerswidth+'px;height:'+tableheight+'px;background-color:'
        +textbgcolor+';-moz-opacity:'+
        translayersopacity/100+';overflow:hidden"> </span>')
        translayersleftpos+=translayerswidth
        translayersopacity-=translayersfactor

        if (translayersopacity<0) {translayersopacity=0.001}
        }
        translayersleftpos=tablewidth-translayersleftpos
        translayersopacity=0.001
        for (i=0;i<=translayersmax-1;i++) {
            document.write('<span ID="transright'+i+'"
style="position:absolute;top:0px;left:'
            +translayersleftpos+'px;width:'+
            translayerswidth+'px;height:'+tableheight+'px;background-color:'+textbgcolor+';-moz-opacity:'
            +translayersopacity/100+';"> </span>')
            translayersleftpos+=translayerswidth
            translayersopacity+=translayersfactor
        }
    }

    document.write('</div>')
    if (ns6) {
        document.write('<span ID="tickersize"
style="position:absolute;top:0px;left:-5000px;
            visibility:hidden">'+content+'</span>')
    }
}

function doscroll(){
    if (scrollready) {
        if(ns4){
            document.ticker.left+=-step;
            if (document.ticker.left<document.marker.pageX+1*textborder) {
                document.ticker.clip.left+=step;
            }

            document.ticker.clip.right+=step;
            if(document.ticker.left<-textcontentwidth+document.marker.pageX) {
                document.ticker.left=textwidth+document.marker.pageX-1*textborder;
                document.ticker.clip.left=0
                document.ticker.clip.right=0
            }
        }
        if (ie) {
            document.all.ticker.style.posLeft+=-step
            if (document.all.ticker.style.posLeft<-textcontentwidth) {
                document.all.ticker.style.posLeft=textwidth
            }
        }
        //
        if (ns6) {
        document.getElementById('ticker').style.left=parseInt(document.getElementById('ticker').style.left)-step
            if
(parseInt(document.getElementById('ticker').style.left)<-textcontentwidth)
{
                document.getElementById('ticker').style.left=textwidth
            }
        }
        timer=setTimeout("doscroll()",50)
    }
    else {
        clearTimeout(timer)
    }
}

function DL_GetElementLeft(eElement) {
var nLeftPos = eElement.offsetLeft;
var eParElement = eElement.offsetParent;
while (eParElement != null) {

    nLeftPos += eParElement.offsetLeft;
eParElement = eParElement.offsetParent;
}
return nLeftPos;
}

function DL_GetElementTop(eElement) {
var nTopPos = eElement.offsetTop;
var eParElement = eElement.offsetParent;
while (eParElement != null) {

nTopPos += eParElement.offsetTop;
eParElement = eParElement.offsetParent;
}
return nTopPos;
}

function initscroller(){
.....
    if (ns6) {
        textcontentwidth=document.getElementById('tickersize').offsetWidth
        document.getElementById('roof').style.left=DL_GetElementLeft(document.getElementById('marker'));
        document.getElementById('roof').style.top=DL_GetElementTop(document.getElementById('marker'));
        document.getElementById('ticker').style.left=textwidth
        document.getElementById('ticker').clip='rect(0px,
'+textcontentwidth+'px, '+(textheight)+'px, 0px)';
        document.getElementById('roof').style.visibility="visible";
        document.getElementById('ticker').style.visibility="visible";
    }
    doscroll()
}

function setscrollready(whatanswer) {
    if (whatanswer==1) {
        scrollready=true
        checkscroll()
    }
    else {
        scrollready=false
    }
}

function checkscroll() {
    clearTimeout(timer)
    if (scrollready) {
        doscroll()
    }
}
function reopenpage() {
    history.go(0)
}
window.onresize=reopenpage
window.onload=initscroller
</script>

</td>
</td>
</tr>
</table>
</body></html>

Reply to this Message

Stephen Chalmers - 31 Jul 2005 03:52 GMT

> Hi,
>
[quoted text clipped - 8 lines]
> Thank you in advance,
> Micky

<SNIP>
The code as posted references undeclared variables and therefore is not testable.
Layer movement is slower under Gecko browsers, so I would guess that the relevant function is being called too often.

--
Stephen Chalmers

Reply to this Message

Webmaster Forum / HTML, CSS, Scripts / JavaScript / July 2005

Text Scroller: scrolling stops in Firefox