Add point to point panning API

[LeoNatan]

For various controls, we need an API that will allow the users to specify two points, and let the system perform a pan/scroll from one point to the other. For instance, a picker needs this to perform selection.

[LeoNatan]

Perhaps API should provide two variants; one in point units and one in percentage units.

[DanielMSchmidt]

EarlGrey provides a swipeSlowInDirectionWithStartPoint function. Could this be an option for us?

I mean it is not optimal, but could be well enough

[DanielMSchmidt]

Did a bit more research, this EarlGrey utility looks exactly like the thing we need: GREYPathGestureUtils, it is used e.g. in the Swipe Action, which is used by scrollInDirectionWithStartPoint.

My idea would be to internally extend EarlGrey to support "swipe from here to there in x seconds". Does this sound like a good idea to you? Would be willing to try a PR ;)

[LeoNatan]

Sounds good. If you can expose that method to the JS world, it would be lovely.

[DanielMSchmidt]

I will have a look at this next weekend ;) Would really help me to test my drawer library.

[rotemmiz]

This PR by @DanielMSchmidt will solve it.

[jsierles]

Is this supported now?

[LeoNatan]

Sorry, not yet.

[jsierles]

OK, thanks. Is there a workaround for testing a Picker?

[LeoNatan]

Pickers are looked at right now for a proper fix, but I don't have a timeline currently. We also found another issue which may need this point-to-point API, so this may come soon too. Again, cannot say when.

[jsierles]

OK, thanks for the update. Can you recommend a way to simulate the behavior of the picker directly? Just so one can move forward within the app.

[LeoNatan]

You can try mocking the screen or functionality for the tests. Not optimal but I can't think of something else right now. Maybe @rotemmiz may have an idea?

[LeoNatan]

This is being discussed seriously in #589. Closing this issue in favor of that one.