position of an image..

Using javascript, I'd like to place a layer over an image (don't ask why *s*), but I don't know how to get to the top left corner of the image. How do I do that.

I've tried :
document[imgname].top
but that doesn't seam to work..

I'd appreciate any help, thanks..
LVL 1
lar_jensAsked:
Who is Participating?

Improve company productivity with a Business Account.Sign Up

x
 
jbirkConnect With a Mentor Commented:
Your welcome!
-Josh
0
 
jbirkCommented:
OK, it's different for IE and Netscape.  For netscape it's x and y, and IE it's pffsetLeft and offsetTop.  So add a quick check:

if (document.layers)
 {top = document[imgname].y
  left = document.[imgname].x
 }
else if (document.all)
 {top = document[imgname].offsetTop
  left = document.[imgname].offsetLeft
 }

-Josh
0
 
jbirkCommented:
Incidentally, one way to find out what the supported properties are for an object is to use a for/in loop on that object and print the data out to the document or alert it or whatever.  I did this for this question:
for (prop in document.images[0])
  alert("name: "+prop+"; value= "+document.images[0][prop])

It took a really long time in IE since there are so many properties, so perhaps a document.write wouild have been better, but it told me what I needed to know:)

-Josh
0
Get 10% Off Your First Squarespace Website

Ready to showcase your work, publish content or promote your business online? With Squarespace’s award-winning templates and 24/7 customer service, getting started is simple. Head to Squarespace.com and use offer code ‘EXPERTS’ to get 10% off your first purchase.

 
lar_jensAuthor Commented:
I'm using IE for the moment..

But

document[imgname].offsetTop and
document[imgname].offsetLeft

doesn't seam to work..
Instead

document.images[0].offsetTop and
document.images[0].offsetLeft
seams to work..

Weird.. How come?
And my layer will not position itself over the image (the image is centered), but stays on the left.. How can I fix that?

- LJJ
0
 
jbirkCommented:
Not sure why the two different array indexing is different?  Must be a bug? It should work just the same.

You say it stays on the left, do you mean, flush left with the image?  If so this is because those are the coordinates you are getting (the upper left corner).  If you want to center your layer, you'll have to do some math.  Compute the widths/heights of each item (the image and the layer), subtract them from each other, divide by two and add that to the left and top coordinates of the image.  That will center your div over the image.

If it's not lining up exactly on the left/top of the image, could you post an example of the code so I can play with it, and get it working on my computer?

-Josh
0
 
lar_jensAuthor Commented:
Yeah, sure..
Take a look at

http://www.handlekurven.no/buttontest/

0
 
jbirkCommented:
The problem was the center tag as you suspected.  The Center tag is outdated however, and using a newer method fixes the problem.  I used the same method you used for centering vertically to center horizontally and it worked fine.  So remove the center tags and modify the file like this:
<table height=100% width="100%" border="0">
<script language="JavaScript">
  var h = document
  document.write("<td valign=MIDDLE align=center>");

That should get it starting in upper left corner of the first image.

-josh
0
 
lar_jensAuthor Commented:
Adjusted points from 50 to 100
0
 
lar_jensAuthor Commented:
thnx..

you've been most helpful.. =)
0
 
lar_jensAuthor Commented:
tihi - I forgot to give you your points..

Sorry about that - I wasn't trying to be rude or anything... =)

0
 
jbirkCommented:
I wasn't worried:)  Just thought answering it would be a reminder...
0
Question has a verified solution.

Are you are experiencing a similar issue? Get a personalized answer when you ask a related question.

Have a better answer? Share it in a comment.

All Courses

From novice to tech pro — start learning today.