[whatwg] Alignment of empty buttons

[Boris Zbarsky]

On 11/25/13 12:59 AM, Ian Hickson wrote:

> It's more like <svg:g>. The CSS model just doesn't apply. Even in Firefox,
> it's not really CSS that's working there. It's some weird proprietary
> variant.

It's really not, once you have a DOM and are inside <option>.

> I mean, as you've pointed out, child nodes of the <select> that
> aren't <option> or <optgroup> are mysteriously hidden

That's <select>, not <option>.

> but also, the <option> elements obey some values of 'display' but don't obey e.g.
> 'position' or 'float';

That's pure CSS: it's a !important rule in a UA stylesheet.  I guess you 
could claim that supporting !important in a UA stylesheet is a 
proprietary extension, albeit one that's in the process of being specified.

> 'white-space' doesn't seem to work right in a <select> or <option>;

   option { white-space: nowrap !important; }

in UA stylesheet.

> the height of the <select> seems to be based in some
> weird way on the height of some of the <option>s...

That's about <select>, not <option>.

> in the drop-down mode, it's even worse

My comments were specifically about <option> in a listbox.  A combobox 
is a different and more complicated story (though even there the layout 
of the <option> itself is pure CSS in Gecko).

Put another way, there is no custom layout code for <option> in Gecko. 
It's all done entirely by the CSS renderer, based on the computed values 
of CSS properties for the element.  Some of those computed values come 
from !important rules in a UA stylesheet, but that's it.

> (By the way, in testing this, I discovered <option label> isn't supported
> in Firefox.

That's correct.  https://bugzilla.mozilla.org/show_bug.cgi?id=40545

> HTH. Also ::first-line on a display:table-row doesn't seem to be work,
> though I couldn't tell if that was per-spec or not. It doesn't seem to
> work for regular <div>s either.)

::first-line on a display:table-row shouldn't work in Gecko right now, 
yes.  Whether it's per-spec depends on which spec you're reading and the 
phase of the moon.  ;)

It should work on a block, of course, and does in my testing.

-Boris