Add documentation for onMomentumScrollEnd

[tomasreimers]

No description provided.

[shergin]

Could you please clarify in the description the difference with onScrollAnimationEnd?
And please use consistent description style, like "Called when ...".

[tomasreimers]

Absolutely! Also, FWIW, I don't think that onScrollAnimationEnd is ever called...

https://snack.expo.io/BJyf5OGIW

react-native/React/Views/RCTScrollView.m

Line 765 in 603cc48

RCT_SEND_SCROLL_EVENT(onMomentumScrollEnd, nil); //TODO: shouldn't this be onScrollAnimationEnd?

[facebook-github-bot]

@shergin has imported this pull request. If you are a Facebook employee, you can view this diff on Phabricator.

[shergin]

@tomasreimers Yeah... You are right. Thank you!
I think, we also have to do:

• Remove onScrollAnimationEnd from documentation and delete all (unused) mentions of it from Android and iOS sources;
• Implement onMomentumScrollBegin on iOS (it already should work on Android) and add this to documentation.

I will add it to my plans. (Or a PR is always welcome. 😄)

[tomasreimers]

@shergin

(1) Done: #15156 (Nothing at FB is someone else's problem, right? ;) )

(2) Already done (I think...):

• Android:

  react-native/ReactAndroid/src/main/java/com/facebook/react/views/scroll/ReactHorizontalScrollView.java

  Line 263 in 968aa56

  ReactScrollViewHelper.emitScrollMomentumBeginEvent(this);

• IOS:

  react-native/React/Views/RCTScrollView.m

  Line 592 in 603cc48

  RCT_SCROLL_EVENT_HANDLER(scrollViewWillBeginDecelerating, onMomentumScrollBegin)

[shergin]

Awesome! Now we just have to mention this in the documentation.

[tomasreimers]

@shergin #15158