[CSS21] anonymous blocks vs run-ins; and Distinguishing block boxes proposal

On Wed, Jul 21, 2010 at 12:16:54AM -0700, fantasai wrote:

> ...
> Section 9.2.1.1 Anonymous block boxes
> 
>   # In other words: if a block box (such as that generated for the DIV
>   # above) has another block box or run-in box inside it (such as the P
>   # above), then we force it to have only block boxes and run-in boxes
>   # inside it.
> 
>   s/another block box or run-in box/a block-level box/
>   s/only block boxes and run-in boxes/only block-level boxes/

I suspect that the explicit mentions of run-ins there was actually a hint as to
some aspects of the intended [or assumed] interaction between sections 9.2.1.1
and 9.2.3.  The spec isn't clear what the interactions should be in all cases,
and indeed existing implementations (at least Webkit and to a lesser extent
Opera) don't seem to have a particularly simple model of how they should
interact.

All the same, the behaviour that I've seen makes me inclined to suggest that
the explicit mentions of run-ins should be retained in each of those cases:
although the evidence isn't unanimous, the principle of avoiding making
unintended normative changes suggests that the explicit mentions of run-ins
should be retained for now at least.


Regarding the more general problem of specifying the interaction between
these two sections, the complicated behaviour I've seen makes me inclined to
wait until we're looking at adding the text that describes the box tree (what
boxes are siblings or children of what other boxes).  I could post or send
test cases now, but there are some other issues with those sections
(such as the mention of line box in 9.2.1.1) that I hope will get cleaned
up before then and that would make it a bit easier to discuss.

pjrm.

Received on Sunday, 8 August 2010 11:25:02 UTC