- From: Simon Fraser <smfr@me.com>
- Date: Thu, 21 Apr 2011 20:05:21 -0700
- To: www-style list <www-style@w3.org>
- Message-id: <D67376FD-3562-4794-B58A-5FA6B3095374@me.com>
On Apr 21, 2011, at 7:27 pm, fantasai wrote: > Transforms > ---------- > > <glazou> http://www.w3.org/mid/AF6CAE42-3067-4B7F-9F6D-31502ECFE327@me.com > glazou: Next is about z-index. > smfr: The Transforms spec says that transformed elements act like > "relatively positioned element". > smfr: Webkit has this just create a pseudo-stacking context (like 'opacity' > does), but FF and maybe IE let z-index work. > smfr: I argued that we don't let left/top/etc apply, so z-index shouldn't > either. So my proposal is that we change the spec to have transforms > create a pseudo-stacking context like 'opacity' instead. > dbaron: I don't particularly care, but I think it might be good to ask > authors. > smfr: If authors want to apply z-index, they can just actually make it > relpos. > fantasai: I think having to use relpos for z-index is confusing anyway. > smfr: Stacking contexts are confusing anyway. > sylvaing: What about opacity? z-index doesn't apply? > smfr: No. > sylvaing: So you're just wanting to make it consistent with opacity. > Sounds good. > RESOLVED: transforms create a pseudo-stacking context, not a full one. > z-index doesn't apply. I realized that was forgetting part of the story here. A transformed element acts as a stacking context (like one with opacity). But it also acts as a positioning container for its descendants, so, for example, a position:relative child's left and top are relative to its transformed ancestor in that case, again as if the transformed element itself has position:relative. I don't think this changes the fact that z-index should not apply to a transformed element (just as 'left' and 'top' do not apply), but I wanted to mention it in case someone disagrees. Simon
Received on Friday, 22 April 2011 03:06:30 UTC