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Re: [css3-transitions] [css3-animations] API for testing transitions and animations

From: Aryeh Gregor <ayg@aryeh.name>
Date: Tue, 14 Feb 2012 13:11:30 -0500
Message-ID: <CAKA+AxnKK1Kx+dmd3Oy2A9zO7zXbDbq5oBtg6L_8LFV8oVN2Dg@mail.gmail.com>
To: Boris Zbarsky <bzbarsky@mit.edu>
Cc: public-css-testsuite@w3.org
On Tue, Feb 14, 2012 at 12:46 PM, Boris Zbarsky <bzbarsky@mit.edu> wrote:
> 1)  It's possible for a regular web page to observe whether some aspects of
> transition/animation behavior (say computed CSS values as functions of time)
> are correct right now.  You could write tests to do such checking; they'd
> just have to be written _very_ carefully if you want to avoid false
> positives and false negatives.  For internal regression test suites, ease of
> writing reliable tests is important, hence APIs to make it easier.

What are examples of how this might work?

> 2)  It's possible for a human observer to detect broken aspects of
> transition/animation behavior even if the page is seeing the right computed
> styles (e.g. think a browser implementation that updates the styles on
> demand but doesn't advance the timeline normally).   Of course depending on
> an API for detecting this is silly, since the implementation is purposefully
> lying to the script, basically.  But we do somewhat care about not allowing
> such implementations to be considered conformant....

Would this be resolved by allowing animated reftests?

>> If the computed values of something change at
>> the wrong rate during a transition or animation, can that actually
>> conceivably break any webpages?
>
> Sure, especially if they change at different wrong rates for different
> animations, right?

What's an example of how this might happen?
Received on Tuesday, 14 February 2012 18:12:21 GMT

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