<div class="any-scroll-view">
  <div ref="body" :style="bodyStyle" class="any-scroll-view__body"><slot></slot></div>
</div>
.any-scroll-view {
  position: relative;
  width: 100%;
  height: 90vh; 
  overflow: hidden;

  &__body {
    transition-timing-function: cubic-bezier(0.1, 0.57, 0.1, 1);
    background: #eee;
    position: absolute;
    width: 100%;
    height: 100%;
  }
}
import AnyTouch from 'any-touch';
export default {
  name: 'any-scroll-view',

  props: {
    // 減速度, 單位px/s²
    acceleration: {
      type: Number,
      default: 3600
    }
  },

  data() {
    return {
      scrollTop: 0,
      scrollLeft: 0,
      transitionDuration: 300
    };
  },

  computed: {
    bodyStyle() {
      return {
        transitionDuration: `${this.transitionDuration}ms`,
        transform: `translate(${this.scrollLeft}px, ${
          this.scrollTop
        }px)`
      };
    }
  },

  mounted() {
    const at = new AnyTouch(this.$el);

    // 第一次觸碰
    at.on('inputstart', (ev) => {
      this.stopRoll();
    });

    // 拖拽開始
    at.on('panstart', (ev) => {
      this.move(ev);
    });

    // 拖拽中
    at.on('panmove', (ev) => {
      this.move(ev);
    });

    // 快速滑動
    at.on('swipe', (ev) => {
      this.decelerate(ev);
    });

    this.$on('hook:destroy', () => {
      at.destroy();
    });
  },

  methods: {
    // https://github.com/nolimits4web/swiper/blob/master/dist/js/swiper.esm.js#L87
    // https://github.com/nolimits4web/Swiper/blob/master/src/utils/utils.js#L25
    getCurrentTranslate() {
      const style = getComputedStyle(this.$refs.body, null);
      const { transform } = style;
      const array = transform.match(/(\-?)(\d)+(\.\d{0,})?/g);
      return { x: Math.round(array[4]), y: Math.round(array[5]) };
    },

    stopRoll() {
      const { x, y } = this.getCurrentTranslate();
      this.moveTo({ scrollTop: y, scrollLeft: x });
    },

    /**
     * 移動body
     * @param {Object} 拖拽產生的數(shù)據(jù)
     * @param {Number} deltaX: x軸位移變化
     * @param {Number} deltaY: y軸位移變化
     */
    move({ deltaX, deltaY }, transitionDuration = 0) {
      this.transitionDuration = transitionDuration;
      this.scrollLeft += deltaX;
      this.scrollTop += deltaY;
    },

    /**
     * 移動到
     */
    moveTo({ scrollTop, scrollLeft }, transitionDuration = 0) {
      this.transitionDuration = transitionDuration;
      this.scrollLeft = scrollLeft;
      this.scrollTop = scrollTop;
    },

    /**
     * 拖拽松手后減速移動至停止
     * velocityX/Y的單位是px/ms
     */
    decelerate(ev) {
      const directionSign = { up: -1, right: 1, down: 1, left: -1 }[
        ev.direction
      ];

      // Top? | Left?
      let SCROLL_SUFFIX = 'Top';
      // x ? | y?
      let AXIS_SUFFIX = 'Y';
      if (ev.velocityX > ev.velocityY) {
        SCROLL_SUFFIX = 'Left';
        AXIS_SUFFIX = 'X';
      }

      // 減速時間, 單位ms
      // t = (v₂ - v₁) / a
      const velocity = ev[`velocity${AXIS_SUFFIX}`];
      this.transitionDuration = Math.round(
        ((velocity * 1000) / this.acceleration) * 1000
      );

      // 滑動距離
      // s = (v₂² - v₁²) / (2 * a)
      const scrollAxis = `scroll${SCROLL_SUFFIX}`;
      this[scrollAxis] +=
        directionSign *
        Math.round(
          Math.pow(velocity * 1000, 2) / (2 * this.acceleration)
        );
    }
  }
};