import type { Ref } from 'vue';
import { watch, onMounted } from 'vue';
const SMOOTH_PTG = 14 / 15;
export default function useMobileTouchMove(
inVirtual: Ref<boolean>,
listRef: Ref<HTMLDivElement | undefined>,
callback: (offsetY: number, smoothOffset?: boolean) => boolean,
): void {
let touched = false;
let touchY = 0;
let element: HTMLElement | null = null;
let interval: NodeJS.Timer | null = null;
const onTouchMove = (e: TouchEvent) => {
if (touched) {
const currentY = Math.ceil(e.touches[0].pageY);
let offsetY = touchY - currentY;
touchY = currentY;
if (callback(offsetY)) {
e.preventDefault();
}
if (interval) {
clearInterval(interval);
}
interval = setInterval(() => {
offsetY *= SMOOTH_PTG;
if (!callback(offsetY, true) || Math.abs(offsetY) <= 0.1) {
if (interval) {
clearInterval(interval);
}
}
}, 16);
}
};
const cleanUpEvents = () => {
if (element) {
element.removeEventListener('touchmove', onTouchMove);
element.removeEventListener('touchend', () => {
touched = false;
cleanUpEvents();
});
}
};
const onTouchEnd = () => {
touched = false;
cleanUpEvents();
};
const onTouchStart = (e: TouchEvent) => {
cleanUpEvents();
if (e.touches.length === 1 && !touched) {
touched = true;
touchY = Math.ceil(e.touches[0].pageY);
element = e.target as HTMLElement;
element.addEventListener('touchmove', onTouchMove, { passive: false });
element.addEventListener('touchend', onTouchEnd);
}
};
onMounted(() => {
watch(
inVirtual,
val => {
listRef.value?.removeEventListener('touchstart', onTouchStart);
cleanUpEvents();
if (interval) {
clearInterval(interval);
}
if (val) {
listRef.value?.addEventListener('touchstart', onTouchStart, { passive: false });
}
},
{ immediate: true },
);
});
}