Imagemaps and layers : request for clarification

Dear Colleagues --

The page$opera_demo.html

uses layer clipping to selectively reveal a single orange
diamond over an inferior layer with blue diamonds.  The
page behaves as expected in NS 4.79, NS 7.1 & IE 6, but
does not do so in Opera 7.23.  The first three browsers
allow imagemap clicks and onmouseovers on the non-masked
portion of the inferior layer, whilst Opera allows these
only on the small revealed region of the superior layer.

The problem can be worked around by adding a third (transparent)
layer, the sole function of which is to handle the imagemap
activity, and this can be seen at

but I would like to know whether Opera or the other three
browsers are behaving in accordance with CSS semantics when

Your comments and advice would be much appreciated.

Philip Taylor
Webmaster, Royal Holloway

P.S. Apologies in advance if my browser detection code fails to
identify your browser; please let me know if this occurs and
I will endeavour to update the browser-identification regexps
to accommodate your browser.

Received on Monday, 1 March 2004 17:29:01 UTC