[ScrollView] Shouldn't become responder if scrollEnabled is false #2411
Description
I am doing a sortable list proof-of-concept with ReactNative. One of the effects I want to achieve is to auto-scroll a long list if the dragged item is near the bottom (or top) of the screen. Like so:
To prevent scroll view from scrolling while an item is dragged, I set ScrollView's "scrollEnabled" prop to false, which seems to do the trick. The only problem is if I use the scrollTo method to programmatically scroll, the scrollView mistakenly thinks a user-initiated scroll event occurred, and tries to steal the responder status.
The chain of events is illustrated by these diagrams:
The way to fix this problem is to check whether scrollEnabled is false in scrollResponderHandleScrollShouldSetResponder.