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RE: [css3-animations][css3-transitions] Make negative durations invalid?

From: Sylvain Galineau <sylvaing@microsoft.com>
Date: Fri, 18 May 2012 19:19:29 +0000
To: "L. David Baron" <dbaron@dbaron.org>
CC: "www-style@w3.org" <www-style@w3.org>
Message-ID: <3C4041FF83E1E04A986B6DC50F0178290A3529FA@TK5EX14MBXC262.redmond.corp.microsoft.com>

[L. David Baron:]
> 
> On Friday 2012-05-18 18:10 +0000, Sylvain Galineau wrote:
> > Both modules currently require negative durations to 'treated as 0s'.
> > [1][2]
> >
> > We have a bug for it [3] based on a thread this past March [4] that
> > showed some agreement that such values should be treated as invalid
> instead.
> >
> > At the moment, a quick getComputedStyle() check shows that:
> > - Opera 11 seems to treat negative durations as invalid
> > - Firefox preserves negative durations
> > - WebKit and recent IE10 builds clamp them to 0s per the current prose
> 
> Given the "Computed value" line, I wouldn't expect the clamping to show up
> in the result of getComputedStyle.

Missed that. That's a rather confusing choice, considering the clamping
behavior.

> It would simplify the Firefox code to either (a) make negative values
> invalid, which I'd prefer or (b) make the clamping be reflected in the
> computed value.

WebKit and IE10 currently do b). I have no strong opinion on either though
a) would seems more consistent with CSS overall, never mind that we treat
negative iteration counts as invalid in animations. 
Received on Friday, 18 May 2012 19:20:03 GMT

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