Pseudo classes for the interesttarget API

[mfreed7]

The explainer for interesttarget proposes four new pseudo classes:

• :has-interest - matches on the invoker when the user is currently showing interest in that invoker.
• :has-partial-interest - matches on the invoker when the user is currently showing partial interest in that invoker. (They have merely focused the invoker, but haven't fully-activated it via the hot-key.)
• :target-of-interest - matches on the target of the invoker when the user is showing interest in the invoker for this target.
• :target-of-partial-interest - matches on the target of the invoker when the user is showing partial interest in the invoker for this target.

To hopefully help with the terminology:

<button interesttarget=foo>The *invoker*</button>
<div popover id=foo>The *target* of the invoker</div>

A few notes:

• It felt slightly easier to understand if :has-interest means "has any kind of interest" (including partial), and :has-partial-interest means "specifically only has partial interest". But suggestions appreciated.
• @dbaron pointed out that these names are kind of ambiguous, and also that there is actually a third permutation (match on the invoker but describe the target) but I’m not sure there are use cases for that third set, so I'm not proposing it at this point.
• As always, the names need bikeshedding. E.g. :has-interest or just :interest? And target-of-interest is somewhat descriptive but still leaves something to be desired. Maybe it’s ok.

Thoughts?

[tabatkins]

Yeah, these naming patterns aren't quite consistent with what we use elsewhere.

What about:

• :interest-invoker (matching any interest) and :interest-invoker(partial | total)? (total keyword just a guess)
• :interest-target and :interest-target(partial | total), same meanings

Do we want to expose a state keyword for things that are potentially interest invokers/targets, but that are currently without any interest? Or is that ambiguous when interest isn't being shown?

[mfreed7]

Yeah, these naming patterns aren't quite consistent with what we use elsewhere.

That doesn't surprise me! Thanks for the help with suggestions.

• :interest-invoker (matching any interest) and :interest-invoker(partial | total)? (total keyword just a guess)

I like both. I assume the second suggestion was :interest-invoker-partial ? If so, I think that works.

• :interest-target and :interest-target(partial | total), same meanings

Those were my initial stabs at names too, but the confusing thing is that the attribute is called interesttarget. So it might be confusing to have :interest-target match not on the element with interesttarget, but instead on the target of that element. Having said that, I'm also ok with this naming. Because I really don't like :interest-target-target.

Do we want to expose a state keyword for things that are potentially interest invokers/targets, but that are currently without any interest? Or is that ambiguous when interest isn't being shown?

Hmm. I think that can be handled with [interesttarget]:not(:interest-invoker), no? Perhaps you just mean it might be convenient to have a shorthand for that?

[tabatkins]

I assume the second suggestion was :interest-invoker-partial ?

No, it was a functional pseudoclass that took a few keywords letting you indicate exactly what variety of interest you wanted to match on (while the non-functional one defaulted to some form of interest that we think is likely the most useful). So :interest-invoker(partial).

So it might be confusing to have :interest-target match not on the element with interesttarget, but instead on the target of that element.

I think that's fine - the interesttarget attribute indicates which element is the interest target. It doesn't indicate that the element with the attribute is the interest target.

Hmm. I think that can be handled with [interesttarget]:not(:interest-invoker), no? Perhaps you just mean it might be convenient to have a shorthand for that?

I wasn't sure there was a way to express that; not all negative selectors actually can be written explicitly in a simple manner. I think a shorthand is convenient, yes, since you're likely writing your actual-interest selectors as just :interest-invoker, and having to add the [interesttarget] (to avoid :not(:interest-invoker) over-matching on the rest of the page) isn't super obvious.

[mfreed7]

No, it was a functional pseudoclass that took a few keywords letting you indicate exactly what variety of interest you wanted to match on (while the non-functional one defaulted to some form of interest that we think is likely the most useful). So :interest-invoker(partial).

Oh! Duh, reading it again, I can see this clearly. I like this idea! Are there other functional pseudo classes that also work without the ()? Either way I like the idea, and my vote would be for :interest-invoker (without ()) to be sugar for :interest-invoker(total) - that's usually the most useful selector, since it's a superset of :interest-invoker(partial).

I think that's fine - the interesttarget attribute indicates which element is the interest target. It doesn't indicate that the element with the attribute is the interest target.

Fair enough.

Do we want to expose a state keyword for things that are potentially interest invokers/targets, but that are currently without any interest? Or is that ambiguous when interest isn't being shown?

Hmm. I think that can be handled with [interesttarget]:not(:interest-invoker), no? Perhaps you just mean it might be convenient to have a shorthand for that?

I wasn't sure there was a way to express that; not all negative selectors actually can be written explicitly in a simple manner. I think a shorthand is convenient, yes, since you're likely writing your actual-interest selectors as just :interest-invoker, and having to add the [interesttarget] (to avoid :not(:interest-invoker) over-matching on the rest of the page) isn't super obvious.

Ok - I guess maybe the shorthand would be :interest-invoker(none) or something?

[tabatkins]

Are there other functional pseudo classes that also work without the ()?

Yes, :host and :host(), for example. We've used it in a few other designs that ended up being dropped, too.

I guess maybe the shorthand would be :interest-invoker(none) or something?

Something like that. possible, maybe.