allow updating allowBubbleDisplay directly

        propMinSdkVersion = 16

        propTargetSdkVersion = propCompileSdkVersion

        propVersionCode = 1

        propVersionName = '3.1.6'

        propVersionName = '3.1.7'

        kotlin_version = '1.2.0'

        support_libs = '27.0.2'

    }

// based on https://blog.stylingandroid.com/recyclerview-fastscroll-part-1

class FastScroller : FrameLayout {

    var isHorizontal = false

    var allowBubbleDisplay = false

    private var handle: View? = null

    private var bubble: TextView? = null

    private var currHeight = 0

    private var currWidth = 0

    private var bubbleOffset = 0

    private var allowBubbleDisplay = false

    private var fastScrollCallback: ((Int) -> Unit)? = null

    private val HANDLE_HIDE_DELAY = 1000L

    constructor(context: Context, attrs: AttributeSet, defStyle: Int) : super(context, attrs, defStyle)

    fun setViews(recyclerView: RecyclerView, swipeRefreshLayout: SwipeRefreshLayout? = null, allowBubbleDisplay: Boolean = false, callback: ((Int) -> Unit)? = null) {

    fun setViews(recyclerView: RecyclerView, swipeRefreshLayout: SwipeRefreshLayout? = null, callback: ((Int) -> Unit)? = null) {

        this.recyclerView = recyclerView

        this.swipeRefreshLayout = swipeRefreshLayout

        updatePrimaryColor()

            }

        })

        this.allowBubbleDisplay = allowBubbleDisplay

        fastScrollCallback = callback

    }