Floating sticky dialog for RecyclerView

StickyDialog.kt

/**
 * Sticky dialog for [RecyclerView].
 * Create instance when RecyclerView will be initialized and 
 * call [StickyDialog.show] when a user clicked by item in a list
 *
 * @author Ivan V on 31.07.2020.
 * @version 1.0
 */
class StickyDialog : DialogFragment {

    private var rView: RecyclerView? = null
    private var listener: EventListener? = null

    private var posX: Int = 0
    private var posY: Int = 0

    companion object {
        fun newInstance(source: RecyclerView?): StickyDialog {
            return StickyDialog(source)
        }
    }

    constructor() {}
    
    constructor(rView: RecyclerView?) {
        this.rView = rView
        this.rView!!.addOnItemTouchListener(object : RecyclerView.OnItemTouchListener {
            override fun onTouchEvent(rv: RecyclerView, e: MotionEvent) {}
            override fun onRequestDisallowInterceptTouchEvent(disallowIntercept: Boolean) {}
            override fun onInterceptTouchEvent(rv: RecyclerView, e: MotionEvent): Boolean {
                if (e.action == MotionEvent.ACTION_DOWN) {
                    posX = e.x.toInt()
                    posY = e.y.toInt()
                }
                return false
            }
        })
    }

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setStyle(STYLE_NO_FRAME, R.style.Theme_AppCompat_Dialog)
    }

    override fun onCreateView(
        inflater: LayoutInflater,
        container: ViewGroup?,
        savedInstanceState: Bundle?
    ): View? {
        val view = inflater.inflate(R.layout.dialog_layout, container, false)
        // Init view, listener e.t.c
        return view
    }

    override fun onResume() {
        super.onResume()
        setupParams()
    }

    private fun setupParams() {
        val window = dialog!!.window
        window?.setBackgroundDrawableResource(android.R.color.transparent)
        val layoutParams = window?.attributes
        layoutParams?.gravity = Gravity.TOP or Gravity.START
        layoutParams?.dimAmount = 0.1f
        layoutParams?.x = posX
        layoutParams?.y = posY
        window?.attributes = layoutParams
    }

    fun show(manager: FragmentManager, listener: EventListener?) {
        super.show(manager, null)
        this.listener = listener
    }

    override fun onDismiss(dialog: DialogInterface) {
        super.onDismiss(dialog)
        rView = null
        listener = null
    }
    
    interface EventListener {
        fun copy()
        fun edit()
        fun delete()
    }
}