Re: Determining number of visible OPTIONs in a SELECT

Hi Ian,

I assume you are using mySelect.style.height rather than mySelect.size.  Otherwise, this would be a moot discussion.  

IE makes it really hard to work this out because it changes the font size to fit the client height of the select, ignoring any style properties.  I just spent about 10 minutes trying to figure out the algorithm it uses to select a font size, but was unable to see a pattern.  If you do know the pattern (and you don't mind seeing a short blink, you could do this:

var foo = document.getElementById('foo'); // get SELECT element
foo.style.visibility="hidden"; // hide it while we figure this out
foo.style.height="auto"; // ignore style.height
var oldSize=foo.size, oldHeight=foo.style.height; 
foo.size=1; //squish to one row
var height = foo.clientHeight; // get height of one row
foo.size=oldSize; // restore
foo.style.height=oldHeight;
foo.style.visibility="visible";
var optionHeight = IEfontFormula(foo.clientHeight, height);

The IEfontFormula function would determine the height of the row by applying the formula MS uses to select a font size for the OPTIONs.  At this point, you are probably better off using an UL instead of a SELECT:

<style>
#myUL {
  padding: 0px;
  margin: 0px;
  border: 0px;
  height: auto; 
  width: 100%; 
  display: block; 
  list-style: none;
}
#myUL LI {
  text-align: left;
  padding: 0px;
  margin: 0px;
  border: 0px;
  height: 20px;
  width: 100%;
  display: block;
  overflow: hidden;
  text-decoration: none;
}
.oddLi {
  background-color: silver
}
</style>
<DIV style="height: 70px; width: 150px; overflow: auto; border: 1px solid black;">
  <UL id="myUL">
    <LI class="oddLi">Row one</LI>
    <LI>Row two</LI>
    <LI class="oddLi">Row three</LI>
    <LI>Row four</LI>
  </UL>
</DIV>

Regards,

-- John

http://e-numera.com/ 

--- In [email protected], Ian Petersen <ispeters@g...> wrote:
>
> Hello all,
> 
> Does anyone know how to find out how many OPTION nodes are visible in
> a given SELECT in Internet Explorer?
> 
> In Mozilla I can ask the SELECT and one of its OPTIONs for their
> offsetHeights and do some division, but IE always returns zero for the
> OPTION's offsetHeight, so that won't work.
> 
> The reason I'm asking is that I'm trying to "page" through some data,
> and I'd like to show one list-full of list items per page.  I just
> can't figure out how many list items that is in IE.
> 
> Thanks,
> Ian
> 
> --
> Tired of pop-ups, security holes, and spyware?
> Try Firefox: http://www.getfirefox.com
>



[Non-text portions of this message have been removed]



------------------------ Yahoo! Groups Sponsor --------------------~--> 
Get fast access to your favorite Yahoo! Groups. Make Yahoo! your home page
http://us.click.yahoo.com/dpRU5A/wUILAA/yQLSAA/9rHolB/TM
--------------------------------------------------------------------~-> 

Unsubscribe
[email protected]

List info
http://www.quirksmode.org/dom/list.html 
Yahoo! Groups Links

<*> To visit your group on the web, go to:
    http://groups.yahoo.com/group/wdf-dom/

<*> To unsubscribe from this group, send an email to:
    [email protected]

<*> Your use of Yahoo! Groups is subject to:
    http://docs.yahoo.com/info/terms/