Pass useAnimatedGestureHandler via forwardRef - react-native

Question

I'm about to swap the old React Native Animated library with the new React Native Reanimated one to gain performance issues but I have encountered one problem I could not solve.
In all examples I found online, I saw that the GestureHandler, created with useAnimatedGestureHandler, is in the same component as the Animated.View. In reality that is sometimes not possible.
In my previous app, I just pass the GestureHandler object to the component via forwardRef but it seems React Native Reanimated is not able to do that. I don't know whether I have a syntax error or it is just a bug.
const App = () => {
const handlerRef = useAnimatedRef();
const y = useSharedValue(0);
handlerRef.current = useAnimatedGestureHandler({
onStart: (_, ctx) => {
ctx.startY = y.value;
},
onActive: ({translationX, translationY}, ctx) => {
y.value = translationY;
},
onEnd: () => {},
});
const animatedStyles = useAnimatedStyle(() => ({transform: [{translateY: withSpring(y.value)}]}));
const UsingHandlerDirect = () => (
<PanGestureHandler onGestureEvent={handlerRef.current} >
<Animated.View style={[styles.blueBox, animatedStyles]} />
</PanGestureHandler>
)
const UsingHandlerForwardRef = forwardRef(({animatedStyles}, ref) => (
<PanGestureHandler onGestureEvent={ref?.handlerRef?.current}>
<Animated.View style={[styles.redBox, animatedStyles]} />
</PanGestureHandler>
));
return (
<SafeAreaView>
<View style={styles.container}>
<UsingHandlerForwardRef ref={handlerRef} animatedStyles={animatedStyles}/>
<UsingHandlerDirect />
</View>
</SafeAreaView>
);
}
I have saved the GestureHandler in a useAnimatedRef handlerRef.current = useAnimatedGestureHandler({}) to make things more representable. Then I pass the the ref directly into the PanGestureHandler of the UsingHandlerDirect component. The result is that when I drag the blue box the box will follow the handler. So this version works.
But as soon as I pass the handlerRef to the UsingHandlerForwardRef component non of the gesture events get fired. I would expect that when I drag the red box will also follow the handler but it doesn't
Has someone an idea whether it's me or it's a bug in the library?
Cheers

Answer 1

I have given up on the idea to pass a ref around instead, I created a hook that connects both components with each other via context.
I created a simple hook
import { useSharedValue } from 'react-native-reanimated';
const useAppState = () => {
const sharedXValue = useSharedValue(0);
return {
sharedXValue,
};
};
export default useAppState;
that holds the shared value using useSharedValue from reanimated 2
The child component uses this value in the gestureHandler like that
const gestureHandler = useAnimatedGestureHandler({
onStart: (_, ctx) => {
ctx.startX = sharedXValue.value;
},
onActive: (event, ctx) => {
sharedXValue.value = ctx.startX + event.translationX;
},
onEnd: (_) => {
sharedXValue.value = withSpring(0);
},
});
and the Parent just consumes the hook value
const animatedStyle = useAnimatedStyle(() => {
return {
transform: [
{
translateX: -sharedXValue.value,
},
],
};
});
I have created a workable Snack which contains the 2 components - a Child with a blue box and a Parent with a red box