SnapOnScrollListener

SnapOnScrollListener

class SnapOnScrollListener(
        private val snapHelper: SnapHelper,
        var onSnapPositionChangeListener: Utils.OnSnapPositionChangeListener? = null
) : RecyclerView.OnScrollListener() {

    private var snapPosition = RecyclerView.NO_POSITION

    override fun onScrolled(recyclerView: RecyclerView, dx: Int, dy: Int) {
        /*val snapPosition = snapHelper.getSnapPosition(recyclerView)
        val snapPositionChanged = this.snapPosition != snapPosition
        if (snapPositionChanged) {
            onSnapPositionChangeListener?.onScrolled(snapPosition)
            this.snapPosition = snapPosition
        }*/
    }

    override fun onScrollStateChanged(recyclerView: RecyclerView, newState: Int) {
        if (newState == RecyclerView.SCROLL_STATE_IDLE) {
            updatePos(recyclerView)
        } else if(newState == RecyclerView.SCROLL_STATE_DRAGGING){
//            onSnapPositionChangeListener?.onScrolled()
        }
    }

    private fun updatePos(recyclerView: RecyclerView) {
        val snapPosition = snapHelper.getSnapPosition(recyclerView)
        val snapPositionChanged = this.snapPosition != snapPosition
        if (snapPositionChanged) {
            onSnapPositionChangeListener?.onSnapPositionChange(snapPosition)
            this.snapPosition = snapPosition
        }
    }
}