Function normalizeRange

src/components/createDataZoomSlider.ts:18–26

(range: ZoomRange)

const clamp = (v: number, lo: number, hi: number): number => Math.min(hi, Math.max(lo, v));

const normalizeRange = (range: ZoomRange): ZoomRange => {
  let { start, end } = range;
  if (start > end) {
    const t = start;
    start = end;
    end = t;
  }
  return { start: clamp(start, 0, 100), end: clamp(end, 0, 100) };
};

type DragMode = 'left-handle' | 'right-handle' | 'pan-window';