ant-design-vue/es/vc-virtual-list/hooks/useMobileTouchMove.js

An enterprise-class UI design language and Vue-based implementation

import supportsPassive from '../../_util/supportsPassive';
import { watch } from 'vue';
var SMOOTH_PTG = 14 / 15;
export default function useMobileTouchMove(inVirtual, listRef, callback) {
  var touched = false;
  var touchY = 0;
  var element = null; // Smooth scroll

  var interval = null;

  var cleanUpEvents = function cleanUpEvents() {
    if (element) {
      element.removeEventListener('touchmove', onTouchMove, supportsPassive ? {
        passive: false
      } : false);
      element.removeEventListener('touchend', onTouchEnd);
    }
  };

  var onTouchMove = function onTouchMove(e) {
    if (touched) {
      var currentY = Math.ceil(e.touches[0].pageY);
      var offsetY = touchY - currentY;
      touchY = currentY;

      if (callback(offsetY)) {
        e.preventDefault();
      } // Smooth interval


      clearInterval(interval);
      interval = setInterval(function () {
        offsetY *= SMOOTH_PTG;

        if (!callback(offsetY, true) || Math.abs(offsetY) <= 0.1) {
          clearInterval(interval);
        }
      }, 16);
    }
  };

  var onTouchEnd = function onTouchEnd() {
    touched = false;
    cleanUpEvents();
  };

  var onTouchStart = function onTouchStart(e) {
    cleanUpEvents();

    if (e.touches.length === 1 && !touched) {
      touched = true;
      touchY = Math.ceil(e.touches[0].pageY);
      element = e.target;
      element.addEventListener('touchmove', onTouchMove, supportsPassive ? {
        passive: false
      } : false);
      element.addEventListener('touchend', onTouchEnd);
    }
  };

  watch(inVirtual, function (val) {
    listRef.value.removeEventListener('touchstart', onTouchStart, supportsPassive ? {
      passive: false
    } : false);
    cleanUpEvents();
    clearInterval(interval);

    if (val) {
      listRef.value.addEventListener('touchstart', onTouchStart, supportsPassive ? {
        passive: false
      } : false);
    }
  });
}