scrollHandleDidScroll () {
    if (this._scrollHandleIndex === null) {
      // stop when scroll handle is no longer active
      return
    }

    // calculate intermediate scroll position
    let direction = this._scrollHandleIndex === 0 ? -1 : 1
    let duration = (new Date().getTime() - this._scrollHandleStartTime) / 1000
    let delta = direction * Math.pow(duration, 2) * scrollHandleSpeed
    this.scrollTo(this._scrollHandleStartPosition + delta)

    window.requestAnimationFrame(this.scrollHandleDidScroll.bind(this))
  }
/**
   * Triggered at each scroll handle scroll tick.
   */
Triggered at each scroll handle scroll tick.
Triggered at each scroll handle scroll tick .
scrollHandleDidScroll () {
    if (this._scrollHandleIndex === null) {
      return
    }
    let direction = this._scrollHandleIndex === 0 ? -1 : 1
    let duration = (new Date().getTime() - this._scrollHandleStartTime) / 1000
    let delta = direction * Math.pow(duration, 2) * scrollHandleSpeed
    this.scrollTo(this._scrollHandleStartPosition + delta)
    window.requestAnimationFrame(this.scrollHandleDidScroll.bind(this))
  }
scrollHandleDidScroll ( ) { if ( this . _scrollHandleIndex === null ) { return } let direction = this . _scrollHandleIndex === 0 ? - 1 : 1 let duration = ( new Date ( ) . getTime ( ) - this . _scrollHandleStartTime ) / 1000 let delta = direction * Math . pow ( duration , 2 ) * scrollHandleSpeed this . scrollTo ( this . _scrollHandleStartPosition + delta ) window . requestAnimationFrame ( this . scrollHandleDidScroll . bind ( this ) ) }
Triggered at each scroll handle scroll tick.
Triggered at each scroll handle scroll tick .
// stop when scroll handle is no longer active // calculate intermediate scroll position