Re: [CSS21] Does 10.6.7 apply to the root element?

Thanks Håkon:

Vertically, the height is determined by its content. That is, block boxes 
use outside-in width computation and inside-out height computation. The root 
element is constrained horizontally by the initial containing block (ICB) 
which typically corresponds to the width of the window or printing surface.

Have some of you versed about the properness of reduced redundance instead 
of acronymics?
OTOH, does universe contains contents or clip contents, it is simple: Ian 
and David are at the point....
....please do not start another BTW (IMHO, Browsers, iTs War!)....

The viewport:
User agents for continuous media generally offer users a viewport (a window 
or other viewing area on the screen) through which users consult a document. 
User agents may change the document's layout when the viewport is resized 
(see the initial containing block).

Definition of "containing block": (initial one, obv.):

When the viewport is smaller than the area of the canvas on which the 
document is rendered, the user agent should offer a scrolling mechanism. 
There is at most one viewport per canvas, but user agents may render to more 
than one canvas (i.e., provide different views of the same document).

The containing block in which the root element lives is a rectangle with the 
dimensions of the viewport, anchored at the canvas origin for continuous 
media, and the page area for paged media. This containing block is called 
the initial containing block.
**End Of SPEC

I see three free implementations wich are normative (IE, Opera, Moz). 
Really, moz is not considering overflow, instead is computing heights of 
floated element.


 html{ height:100px; }

Where the scrollbars are is not a problem. The real problem is that anybody 
wants to select on viewport, wich is not possible, obviously.

Ignacio Javier

----- Original Message ----- 
From: "Garrett Smith" <>
To: "Anne van Kesteren" <>; <>
Sent: Friday, April 07, 2006 10:54 PM
Subject: Re: [CSS21] Does 10.6.7 apply to the root element?

> Most people think that root is the ICB, and in fact, IE behaves as if
> it were. For example, in IE, documentElement.clientHeight will return
> the viewport's height, but in mozilla, the root's height will grow to
> accomodate it's children.
> Mozilla's behavior is correct, because in reality, the root is not the
> ICB. The root is the root and the ICB is the viewport.
> If overflow on the root is applyied to the viewport instead, this will
> further add to confusion and misunderstanding about the ICB and the
> root.
> Garrett
> On 4/7/06, L. David Baron <> wrote:
>> On Friday 2006-04-07 15:50 +0200, Anne van Kesteren wrote:
>> > Reading 10.6.6
>> > and given
>> > that 'overflow'
>> > acts 
>> > like
>> > 'auto' when applied to the root element does
>> 'overflow' effectively never applies to the root element since when it's
>> set on the root element, it applies to the viewport instead.  This is
>> clarified in changes we've made since the last public draft, so the rule
>> that overflow on the root should be propagated to the viewport is no
>> longer specific to HTML UAs, and is now a must instead of a should.
>> > 
>> > apply
>> > to the root element? Testcase:
>> >
>> >
>> I think that's a bug in Mozilla.
>> -David
>> --
>> L. David Baron                                <URL: >
>>            Technical Lead, Layout & CSS, Mozilla Corporation
> --

Received on Monday, 10 April 2006 08:45:22 UTC