- From: Tab Atkins Jr. <jackalmage@gmail.com>
- Date: Tue, 11 Dec 2012 13:30:50 -0800
- To: Matt Falkenhagen <falken@chromium.org>
- Cc: WHATWG <whatwg@lists.whatwg.org>
On Tue, Dec 11, 2012 at 10:45 AM, Matt Falkenhagen <falken@chromium.org> wrote: > The spec seems unclear on whether a magically aligned element[1] should > follow its anchor when its anchor moves, e.g., by dynamic style changes or > something like CSS animations. > > I think we want the element to follow the anchor. If someone does something > like: > > dialog.show(anchor) > anchor.style.top = ... > > They'd probably expect dialog to end up where anchor is, rather than where > it was when show() was called. Yes, it should follow. The only reason it wouldn't do that is it were explained in terms of a one-shot adjustment of top/left. The fact that it's done in terms of a (not yet specced) anchoring functionality means that as long as the anchor is specified, the two elements should have the correct relationship. > Relatedly, it's not clear what happens if anchor is display: none or is not > in the document when show() is called, but later has a rendered box and is > in the document. And the reverse: if it is in the document when show() is > called and later is removed. The spec defines this - the magical alignment only happens while A and B have rendered boxes. When the conditions don't apply, it's not magically aligned. (The spec's recommendation for CSS is somewhat badly designed for this - assume that it merely forces A to "position:absolute", and while B doesn't have a box, A isn't anchored and is interpreted as a normal abspos box.) ~TJ
Received on Tuesday, 11 December 2012 21:31:40 UTC