Re: [csswg-drafts] [css-transitions-2] Start transitions on discrete animation types (#4441)

Yes, it would be nice to support this.

Apart from perf considerations, I'm a bit concerned about compatibility with option 1. If scripts are, for example, waiting for transitionend events and then asserting their `propertyName` is such-and-such, then firing transitions for other events could lead to breakage.

Option 2 would still result in extra `transitionrun` and `transitioncancel` events but I expect far less content is actually listening to them so they are less likely to produce breakage.

What about not allowing `all` or any shorthand to ever match discrete properties but still creating transitions for them (using the behavior from option 1) if they are explicitly listed? e.g. `transition-property: all, overflow-x`?

I suppose that runs the risk that if a longhand is promoted to a shorthand we might need to special case it so it keeps working (depending on how we define a discrete property). Then again, any content listening for `transitionrun` events on the (now) shorthand name, would already break since the UA would start firing events on the corresponding longhand names instead.

The other option that comes to mind is simply to add extra syntax for this, be it an extra property (`transition-property-set: discrete-too`) or extra syntax attached to property names.

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Received on Tuesday, 22 October 2019 22:55:17 UTC