- From: L. David Baron <dbaron@dbaron.org>
- Date: Thu, 2 Feb 2012 18:38:04 +0100
- To: Aryeh Gregor <ayg@aryeh.name>
- Cc: "Tab Atkins Jr." <jackalmage@gmail.com>, Brad Kemper <brad.kemper@gmail.com>, Brian Manthos <brianman@microsoft.com>, Sylvain Galineau <sylvaing@microsoft.com>, www-style list <www-style@w3.org>, fantasai <fantasai@inkedblade.net>
On Thursday 2012-02-02 12:19 -0500, Aryeh Gregor wrote: > On Thu, Feb 2, 2012 at 5:23 AM, Tab Atkins Jr. <jackalmage@gmail.com> wrote: > > I don't understand how this would accomplish what you want. Assume > > that the font-size was originally 15px, so this resolves to .2em. Then > > the element changes to font-size:30px. This then resolves to .1em, > > *not* to 6px like I think you want. If you were counting on this to > > work with inheritance, ems are never inherited - they get computed > > into px (this is why line-height can be specified with a <number> as > > well). > > ems are inherited in transforms: > > data:text/html,<!doctype html> > <div style="font-size:0;transform:translate(5em)"> > <div style="height:100px;width:100px;background:red; > font-size:20px;transform:inherit">Translated</div></div> > > The div is translated in IE10 Developer Preview, Firefox 13.0a1, and > Opera Next 12.00 alpha, although not in Chrome 18 dev. (Make sure to > prefix 'transform' appropriately.) Whether this makes any sense is > perhaps debatable, but it's what most browsers do, and also what the > spec said until quite recently -- Computed value: As specified > (https://www.w3.org/Bugs/Public/show_bug.cgi?id=15797). This is true in Firefox only since we implemented 3-D transforms, which required changing transforms to have a computed value that is actually stored as a list, in order to handle the interaction of percentage translations with other transforms. I think I missed that it would change this behavior, and we probably could change it easily to compute lengths up front. -David -- 𝄞 L. David Baron http://dbaron.org/ 𝄂 𝄢 Mozilla http://www.mozilla.org/ 𝄂
Received on Thursday, 2 February 2012 17:38:36 UTC