- From: Ian Hickson <ian@hixie.ch>
- Date: Tue, 13 Nov 2012 22:38:20 +0000 (UTC)
- To: Edward O'Connor <eoconnor@apple.com>
- Cc: whatwg@lists.whatwg.org
On Tue, 13 Nov 2012, Edward O'Connor wrote:
>
> I don't recall if this was in person or in email, but I think Tab made a
> compelling argument in favor of changing the implementation of hidden=""
> to be
>
> [hidden] {
> display: none !important;
> }
>
> in the UA stylesheet.
It's a non-starter (assuming !important in the UA style sheet means that
it cascades after the !important user sheet), because it means that you
can't change [hidden] from being implemented using 'display' to being
implemented using 'opacity' or some similar solution, which you typically
want for transitions to work well.
> Consider a bunch of thingies, represented in the DOM with a pile of
> <div>s. Some of them are hidden.
>
> <div id=thing0 class=thing>...</div>
> <div id=thing1 class=thing>...</div>
> ...
> <div id=thing46 class=thing>...</div>
> <div id=thing47 class=thing hidden>...</div>
> <div id=thing48 class=thing>...</div>
> ...
> <div id=thing84 class=thing>...</div>
> <div id=thing85 class=thing hidden>...</div>
> <div id=thing86 class=thing>...</div>
> ...
> <div id=thingN class=thing>...</div>
>
> These thingies are flexboxes:
>
> .thing {
> display: flex;
> }
You just have to write .thing:not([hidden]), or have an explicit [hidden]
rule. It's not a big deal.
It's like how if you say
* { font: inherit; }
...you break <pre> and <h1>. It's not a big deal, you just set the fonts
on those too.
The better solution would be for us to cascade the display type separately
from the rendering tree inclusion/exclusion decision, but that boat sailed
a long time ago.
(You get similar problems e.g. with:
strong { text-decoration: blink; }
.thing { text-decoration: underline; }
<strong>...</strong>
<span class="thing">...</span>
<strong class="thing">...</strong> -- oops
...here the last one cascades unexpectedly because orthogonal decisions
are being cascaded together.)
--
Ian Hickson U+1047E )\._.,--....,'``. fL
http://ln.hixie.ch/ U+263A /, _.. \ _\ ;`._ ,.
Things that are impossible just take longer. `._.-(,_..'--(,_..'`-.;.'
Received on Tuesday, 13 November 2012 23:01:44 UTC