Sent by Eric A. Meyer on 26 February 2002 19:07
At 15:49 -0800 2/26/02, James Aylard quoted and wrote:
>> This thread in particular:
>> http://lists.w3.org/Archives/Public/www-style/2001Oct/0107.html
>>
>> I believe that this is the origin of the problem maybe:
>> http://www.w3.org/TR/REC-CSS2/visuren.html#containing-block
>
> But IMO these references don't validate the claim about not being able
>to set a height of 100%. So I assume that the assertion is incorrect, and
>that while there are caveats, there is no problem setting a height of 100%
>on block-level elements, at least.
I'll do my best to shed some light on the subject (and hopefully
not throw gasoline on the fire). You can always, always, always give
a block-level element a 'height' of '100%'. This value will make the
element's content height exactly as tall as its containing block--
which means if you add padding, borders, or margins to the element it
will be taller than its containing block.
Where things gets fuzzy is in the definition of a containing block
for an element that doesn't have any positioned ancestors. In such a
case, the containing block is the root element. The root element is
not necessarily coincident with the browser window, so just setting a
table (for example) to have 'height: 100%' doesn't guarantee that it
will be as tall as the browser window[1]. I think that was the point
of the original question that started this thread.
We can argue about what the root element's containing block is or
isn't until the cows turn purple, as other have done before us. Some
think it should be the browser window. Others think it should be the
'body' element, which is not the same as the browser window. Still
others claim it should be the 'html' element, which may or may not be
the same as the browser window. If you go to CSS2:10.1, you see
this: "1. The containing block (called the initial containing block)
in which the root element lives is chosen by the user agent."
Which basically means user agents (browsers) get to do what they
want in this regard, and there is no One Right Answer. Unfortunately.
[1] Which might be a good thing, in the case of a table with more
content than the browser window can display at once.
--
Eric A. Meyer (http://www.meyerweb.com/eric/), List Chaperone
"CSS is much too interesting and elegant to be not taken seriously."
-- Martina Kosloff (http://www.mako4css.com/)
