react-native-gesture-handler/src/v3/hooks/gestures/rotation/useRotationGesture.ts

Declarative API exposing native platform touch and gesture system to React Native

import type { GestureEvent, HandlerData } from '../../../types';
import { SingleGestureName } from '../../../types';
import { useGesture } from '../../useGesture';
import {
  getChangeEventCalculator,
  useClonedAndRemappedConfig,
} from '../../utils';
import type {
  RotationExtendedHandlerData,
  RotationGesture,
  RotationGestureConfig,
  RotationGestureInternalConfig,
  RotationGestureProperties,
  RotationHandlerData,
} from './RotationTypes';

function diffCalculator(
  current: HandlerData<RotationExtendedHandlerData>,
  previous: HandlerData<RotationExtendedHandlerData> | null
) {
  'worklet';
  return {
    rotationChange: previous
      ? current.rotation - previous.rotation
      : current.rotation,
  };
}

function fillInDefaultValues(event: GestureEvent<RotationExtendedHandlerData>) {
  'worklet';
  event.rotationChange = 0;
}

function transformRotationProps(
  config: RotationGestureConfig & RotationGestureInternalConfig
) {
  config.changeEventCalculator = getChangeEventCalculator(diffCalculator);
  config.fillInDefaultValues = fillInDefaultValues;

  return config;
}

const RotationPropsMapping = new Map<string, string>();

const EMPTY_ROTATION_CONFIG: RotationGestureConfig = {};

export function useRotationGesture(
  config: RotationGestureConfig = EMPTY_ROTATION_CONFIG
): RotationGesture {
  const rotationConfig = useClonedAndRemappedConfig<
    RotationGestureProperties,
    RotationHandlerData,
    // no internal props, pass record as RotationGestureProperties maps everything to never
    Record<string, unknown>,
    RotationExtendedHandlerData
  >(config, RotationPropsMapping, transformRotationProps);

  return useGesture(SingleGestureName.Rotation, rotationConfig);
}