- From: Tab Atkins Jr. <jackalmage@gmail.com>
- Date: Tue, 24 Jan 2012 11:26:52 -0800
- To: "L. David Baron" <dbaron@dbaron.org>
- Cc: Brian Manthos <brianman@microsoft.com>, Sylvain Galineau <sylvaing@microsoft.com>, fantasai <fantasai@inkedblade.net>, www-style list <www-style@w3.org>
On Tue, Jan 24, 2012 at 11:17 AM, L. David Baron <dbaron@dbaron.org> wrote: > On Tuesday 2012-01-24 19:03 +0000, Brian Manthos wrote: >> Tab: >> >Brian: >> >> The fact that "background-position: 10%;" and "background-position: calc(10%);" >> >> can result in differ renderings is perhaps unfortunate, but required by the specs as I read them. >> > Yes, it's currently required by the specs. I've stated this several times. >> >> You might be saying that. My interpretation of David's comments >> is that he was saying otherwise. > > I don't understand the current calc() spec well enough to comment on > what it says. > > However, I firmly believe that if Tab's assertion about what it > currently says is correct (which I believe is at the very least what > it's trying to say), then the spec is wrong and needs to be fixed. > I think calc() should not have any discontinuities, i.e., putting > "calc()" around a valid value shouldn't change its behavior, and > putting a "+1px" inside a calc() should move change the result by > 1px. I earlier quoted the relevant parts of the current spec for fantasai: "A math expression has a resolved type, which is one of ‘<length>’, ‘<frequency>’, ‘<angle>’, ‘<time>’, or ‘<number>’. [...] If percentages are accepted in the context in which the expression is placed, a PERCENTAGE token has the type of the value that percentages are relative to; otherwise, a math expression containing percentages is invalid." I agree that the spec should be changed here. ~TJ
Received on Tuesday, 24 January 2012 19:27:47 UTC