[css-animations-2] Should there be 2 trigger-scope properties?

[nt1m]

I noticed all the properties are timeline-trigger-*, but trigger-scope is not prefixed with timeline. I saw the spec has event-trigger-* as well, but I see no reason to have the scope be shared when event-trigger and timeline-trigger names are independent.

cc @bramus

[ydaniv]

@nt1m I think the idea was to follow the timeline-scope property which also works the same across both scroll-timelines and view-timelines.
Currently we resolved to change the behavior of this property to limit scope instead of "lifting" it, nonetheless, I don't think we gave any thought about scoping a name that may be used for both types.
On one hand, you may want to be explicit about the type you want to scope and not affect the other.
On the other hand, it may be too specific to have to declare this per type?

Anyhow, these should probably follow the same logic.

@fantasai, @flackr WDYT?

[bramus]

I see no reason to have the scope be shared when event-trigger and timeline-trigger names are independent.

I wasn’t 100% following along during the early discussions, but I always took it for granted that the names were not independent – similar to {scroll|view}-timeline which @ydaniv already pointed out. This was also reconfirmed during the F2F in Paris in which we decided to add trigger-scope (#12581 (comment))

Using the same namespace allows one to have different types of triggers for different types of devices (for example), although I can’t really come up with a scenario where you’d want to switch from an event-trigger to a timeline-trigger.

Passing over to @DavMila / @flackr / @szager-chromium to chime in here.

Currently we resolved to change the behavior of this property to limit scope instead of "lifting" it

Yes, see #13241 for the PR. This is also how it’s implemented in Blink.

Note that we also resolved in #12581 (comment) to do the same for timeline-scope, in order to have all *-scope properties work in a similar manner.

[ydaniv]

Yeah, I think I can explain even better (:
Since timelines are consumed by the animation-timeline property regardless of their type, having same name for different types actually clashes, right?
For example:

.source-scroll {
  scroll-timeline: --tl;
}

.source-view {
  view-timeline: --tl;
}

.target {
  animation-timeline: --tl;
}

So in the above example the names clash anyway, regardless of type.

And with event-trigger and timeline-trigger we have the same mechanism where these are both consumed by the animation-trigger property.
So regardless of type, the names clash.

So I think the answer is: there should be a single trigger-scope property.

[DavMila]

So in the above example the names clash anyway, regardless of type.

And with event-trigger and timeline-trigger we have the same mechanism where these are both consumed by the animation-trigger property. So regardless of type, the names clash.

So I think the answer is: there should be a single trigger-scope property.

Yeah this is the way I viewed it as well and why we addressed name clashes between the different types in #12581. Both properties are adding to a set of names that can be referred to by animation-trigger. So perhaps in that respect their names are not totally independent.