useEvent

This is a low-level hook returning an event handler that will be invoked with native events, which should be used in order to create custom event handler hooks, like useAnimatedGestureHandler or useAnimatedScrollHandler.

Arguments

handler [function]

Handler that will receive an event object with a native payload, which can be passed to the custom handler hook's worklets.

• event [object] - event object. The payload can differ depending on the type of the event.

eventNames [Array]

Array of event names that will be handled by handler.

rebuilt [boolean]

Value indicating whether the handler should be rebuilt.

Returns

The hook returns an event handler that will be invoked when a native event is dispatched.

Example

function useAnimatedPagerScrollHandler(handlers, dependencies) {
  const { context, doDependenciesDiffer } = useHandler(handlers, dependencies);

  return useEvent(
    (event) => {
      'worklet';
      const { onPageScroll } = handlers;

      if (onPageScroll && event.eventName.endsWith('onPageScroll')) {
        onPageScroll(event, context);
      }
    },
    ['onPageScroll'],
    doDependenciesDiffer,
  );