react-native-reanimated-carousel/lib/module/hooks/useVisibleRanges.js

Simple carousel component.fully implemented using Reanimated 2.Infinitely scrolling, very smooth.

import { useDerivedValue } from "react-native-reanimated";
export function useVisibleRanges(options) {
  const {
    total = 0,
    viewSize,
    translation,
    windowSize: _windowSize = 0
  } = options;
  const windowSize = total <= _windowSize ? total : _windowSize;
  const ranges = useDerivedValue(() => {
    const positiveCount = Math.round(windowSize / 2);
    const negativeCount = windowSize - positiveCount;
    let curIndex = Math.round(-translation.value / viewSize);
    curIndex = curIndex < 0 ? curIndex % total + total : curIndex;
    const negativeRange = [(curIndex - negativeCount + total) % total, (curIndex - 1 + total) % total];
    const positiveRange = [(curIndex + total) % total, (curIndex + positiveCount + total) % total];

    if (negativeRange[0] < total && negativeRange[0] > negativeRange[1]) {
      negativeRange[1] = total - 1;
      positiveRange[0] = 0;
    }

    if (positiveRange[0] > positiveRange[1]) {
      negativeRange[1] = total - 1;
      positiveRange[0] = 0;
    }

    return {
      negativeRange,
      positiveRange
    };
  }, [total, windowSize, translation]);
  return ranges;
}
//# sourceMappingURL=useVisibleRanges.js.map