feat(Timeline): expose onScroll prop for ScrollView event handling

[isaacbaroncoder]

Description

This PR adds an onScroll prop to the Timeline component, exposing the native scroll event from the internal ScrollView.

Changes

• Added an optional onScroll prop to TimelineProps.
• Forwarded the onScroll event handler to the internal ScrollView alongside existing scrollEvents.
• Updated typings and documentation for the new prop.

Motivation

In a project I work on that uses react-native-calendars, there was a requirement to create a floating button inside the Timeline that would animate based on the user’s vertical scrolling (shrinking when scrolling down, expanding when scrolling up).

I was frustrated to find that the Timeline component — via the timelineProps — did not expose any prop to capture scroll events, which made it impossible to implement this behavior without modifying the library.

This led me to create a fork to handle the case, and it also motivated me to contribute this small improvement back to the community so others can more easily implement similar features.

Here’s a quick demo showing how exposing the onScroll prop enables UI animations like a floating button reacting to scroll direction:

FAB.mp4

[stale]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.