- From: Jorrit Vermeiren <mercator+w3c@gmail.com>
- Date: Sat, 24 Jan 2009 21:26:38 +0100
- To: Brad Kemper <brad.kemper@gmail.com>
- Cc: Anton Prowse <prowse@moonhenge.net>, "www-style@w3.org" <www-style@w3.org>
On Fri, Jan 23, 2009 at 04:06, Brad Kemper <brad.kemper@gmail.com> wrote: > > On Jan 22, 2009, at 6:57 PM, Brad Kemper <brad.kemper@gmail.com> wrote: > >> On Jan 22, 2009, at 12:11 PM, Anton Prowse <prowse@moonhenge.net> wrote: >> >>> >>> Brad Kemper wrote: >>>> >>>> 3) Even when the author may expect a scroll box to not obscure content, >>>> there are cases where it does so anyway, already. I found such a case last >>>> year, involving absolutely positioned contents [2]. >>> >>>> [2] http://bradclicks.com/cssplay/scrolling%20lists.html (second to last >>>> example on the page) >>> >>> Could you elaborate on this example a little? In various browsers I see >>> that the abspos markers are not rendered on the left. However, this seems >>> to me a bug >> >> Perhaps. But when I see the same thing in every browser I test with, it >> makes me question if it is really a bug or if I just don't know why it's >> doing it. >> >>> (after all, vertical overflow on the ancestor UL is set to visible) and >>> not related in any way to the presence (or otherwise) of the scrolling >>> mechanism. Am I missing the point here? >> >> Well, the bug does not appear unless overflow is hidden, scroll, or auto >> on the ancestor "UL" DIV. Thus my point that "scroll" or "auto" does not >> always mean the contents will be visible, even baring influence of ouside >> elements. >>> >>> > > I forgot to add that even IE8 exhibits the same behavior, so I really tend > to think it must be a "feature, not a bug". Or an unanticipated side effect > of a feature. > I think that's according to the specs and is ultimately caused by section 9.4.1 in the CSS 2.1 spec [1]. See also the other ongoing thread about "Block formatting context and floats" [2]. Setting overflow to something other than 'visible' creates a new block formatting context. Since you can't both create a new BFC and not create one, 'visible' can't always be combined with other values. In fact, at the very bottom of section 11.1 in the CSS 3 box model draft [3] it mentions that some combinations are not possible. The 'overflow-x' in your example gets a computed value of 'auto'. See also Bruno Fassino's overflow tests [4]. Jorrit [1] http://www.w3.org/TR/CSS21/visuren.html#block-formatting [2] http://lists.w3.org/Archives/Public/www-style/2009Jan/0383.html [3] http://www.w3.org/TR/css3-box/#overflow-x [4] http://www.brunildo.org/test/Overflowxy2.html
Received on Saturday, 24 January 2009 20:27:20 UTC