React-native: Add callback to ScrollView scrollTo method after animation

[theodoregold]

This is just a suggestion. I am not a native developer, but it seems a good idea to add a callback for scrollTo method if it is possible.

For example, if a user presses on a "scroll me somewhere button" multiple times, it would be nice to disable this button until scroll animation finishes. It seems this might be a useful callback in some cases.

[theodoregold]

It also seems, that invoking multiple scrollTo with animation makes subsequent calls do it without animation.

[ptomasroos]

Give it a try to use onMomentumScrollEnd

[theodoregold]

@ptomasroos Couldn't find any documentatin about onMomentumScrollEnd. I tried it and it only works if user manually scrolls. Not when you call a scrollTo with animation.

[bd-arc]

Hi there! This one is also an issue for us. Let me give you a concrete use case.
We've created our own swiper plugin on top of the ScrollView component, but we aren't able to provide a reliable callback when swiping because scrollTo() doesn't offer one.

As suggested by @ptomasroos, we've tried using onMomentumScrollEnd. But, as stated by @teodors, the event is fired only when there is a user interaction (e.g. it won't work if we scroll programmatically). Moreover, as explained in ScrollView's source code, enabling momentum events on Android can be expensive.

Another lead was to specify a duration for the scroll animation, and then to defer the firing of the callback according to it, but scrollTo() doesn't accept a custom duration either. A PR was made, but it hasn't been active for a while.

That's why adding a callback to scrollTo() would be really helpful.

[sakulstra]

we've currently a usecase where we want to synchronize multiple scrollViews... a scrollView callback would be pretty neat to handle unbouncing

[ABleas]

I have a similar use case to make updates based on where a scrollView ends up, with or without gesture input. Can use setTimeout() to approximate, but it's not ideal.

[mfrachet]

Any new informations concerning this issue ?

[hramos]

Hi there! This issue is being closed because it has been inactive for a while. Maybe the issue has been fixed in a recent release, or perhaps it is not affecting a lot of people. Either way, we're automatically closing issues after a period of inactivity. Please do not take it personally!

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[ro-savage]

@hramos - This is still an issue, and I am running into the same thing. Would be a nice feature to have.

[hramos]

As it happens, we're using GitHub to track bugs in React Native. If you'd like to submit this as a feature request, please go ahead and create an entry on Canny. It has a voting system and if the feature gets a good amount of votes, it will have a greater chance of being implemented by the community.

[Jasbir23]

+1 Much needed

[askday]

+1