react-smooth-slider/src/TouchHelper.js

export default class {
  start = { x: 0, y: 0 };
  end = { x: 0, y: 0 };
  touches = 0;
  isScrolling = false;
  swiped = false;

  getAverage = (touches, axis) => (
    Array.from(touches).reduce((prev, cur) => prev + cur[`client${axis}`], 0) / touches.length
  )

  onTouchEnd = () => {
    this.isScrolling = false;
    this.start = { x: 0, y: 0 };
    this.end = { x: 0, y: 0 };
  }

  onTouchMove = (e) => {
    this.touches = e.touches.length;
    this.end = {
      x: this.getAverage(e.touches, 'X'),
      y: this.getAverage(e.touches, 'Y'),
    };

    if (!this.swiped) {
      this.swiped = true;
    }

    if (!this.isScrolling) {
      this.isScrolling = true;

      this.start = {
        x: this.getAverage(e.touches, 'X'),
        y: this.getAverage(e.touches, 'Y'),
      };
    }
  };
}