W3C home > Mailing lists > Public > www-style@w3.org > October 2011

RE: [css3-animations] display:none, visibility:hidden and animations

From: Brian Manthos <brianman@microsoft.com>
Date: Mon, 3 Oct 2011 19:16:20 +0000
To: Tab Atkins Jr. <jackalmage@gmail.com>, "L. David Baron" <dbaron@dbaron.org>
CC: Boris Zbarsky <bzbarsky@mit.edu>, Sylvain Galineau <sylvaing@microsoft.com>, "www-style@w3.org" <www-style@w3.org>
Message-ID: <9710FCC2E88860489239BE0308AC5D17EF6EC9@TK5EX14MBXC266.redmond.corp.microsoft.com>
Tab:
> Hmm, that's more subtle then.  I *would* still like animations to run
> on display:none subtrees - the fact that we optimize subtrees away
> here seems like it could surprise authors at times, because it's
> detectable now.
>
> However, I'm much more concerned about animations on display:none
> elements.  The justification for subtrees is understandable, but
> stopping or pausing animations on display:none elements themselves is
> just wrong.  There's no efficiency justification for it, and it'll
> definitely be surprising when we gain the ability to animate
> 'display'.

http://www.w3.org/TR/CSS21/visuren.html#display-prop

#9.2.4 The 'display' property
#none
#This value causes an element to not appear in the formatting structure
#(i.e., in visual media the element generates no boxes and has no effect
#on layout). Descendant elements do not generate any boxes either;
# the element and its content are removed from the formatting structure
#entirely. This behavior cannot be overridden by setting the 'display'
#property on the descendants.
#Please note that a display of 'none' does not create an invisible box;
# it creates no box at all. CSS includes mechanisms that enable an element
# to generate boxes in the formatting structure that affect formatting but
# are not visible themselves. Please consult the section on visibility for details.


So, Tab, you want an element that ...
- does not appear in the formatting structure
- generates no boxes
- has no effect on layout
- has its content removed from the formatting structure entirely
- creates no box at all

... to react to animation properties?


How and why?  It seems both "technically troubling" and "conceptually conflicting" with the the quoted "display:none" description.
Received on Monday, 3 October 2011 19:17:00 GMT

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