Function useTouchEvents

src/utils/pointer.ts:149–244

(
    el: GlobalEventHandlers | null,
    data: T,
    options: ITouchEventOptions,
    handle1PointDrag?: (ev: TouchEvent, start: TouchEventStart1PointDrag<T>, end: boolean) => void,
    handle2PointDrag?: (ev: TouchEvent, start: TouchEventStart<T>) => void,
    handle1PointClick?: (ev: TouchEvent, start: TouchEventStart<T>) => void,
)

}

export function useTouchEvents<T>(
    el: GlobalEventHandlers | null,
    data: T,
    options: ITouchEventOptions,
    handle1PointDrag?: (ev: TouchEvent, start: TouchEventStart1PointDrag<T>, end: boolean) => void,
    handle2PointDrag?: (ev: TouchEvent, start: TouchEventStart<T>) => void,
    handle1PointClick?: (ev: TouchEvent, start: TouchEventStart<T>) => void,
) {
    let alwaysSendDragEvent = options.alwaysSendDragEvent ?? false;
    let sendDragEnd = options.sendDragEnd ?? false;
    let initialData = useRef<T>(data);
    let initialTouches = useRef<TouchSimple[]>();
    let lastTouch = useRef<{ time: number, velocity: number, touch: TouchSimple } | null>(null);
    let isDrag = useRef<boolean>(false);
    let latestData = useRef<T>(data);
    let lastPressTime = useRef<number>(0);
    latestData.current = data;
    let handle1PointDragRef = useFunctionRef(handle1PointDrag);
    let handle2PointDragRef = useFunctionRef(handle2PointDrag);
    let handle1PointClickRef = useFunctionRef(handle1PointClick);

    useEffect(() => {
        if (!el) {
            return;
        }

        function sendEvent(ev: TouchEvent) {
            let initial = {data: initialData.current, touches: initialTouches.current!};
            if (!ev.touches || !initial.touches || ev.touches.length !== initial.touches.length) {
                return;
            }

            if (!isDrag.current) {
                if (ev.touches.length > 1 || (ev.touches.length === 1 && touchPixelDist(ev.touches[0], initial.touches[0]) >= 10)) {
                    isDrag.current = true;
                }
            }

            if (ev.touches.length === 1 && handle1PointDragRef.current && (alwaysSendDragEvent || isDrag.current)) {
                handle1PointDragRef.current(ev, { ...initial, isDragging: isDrag.current }, false);
            }
            if (ev.touches.length === 2 && handle2PointDragRef.current) {
                handle2PointDragRef.current(ev, initial);
            }

            if (ev.touches.length === 1) {
                lastTouch.current = {
                    time: 0,
                    velocity: 0,
                    touch: copyTouchList(ev.touches)[0],
                };

            } else {
                lastTouch.current = null;
            }
        }

        function captureInitialAndSend(ev: TouchEvent) {