How to constantly check the state of bottom sheet in kotlin?

Issue

I am trying to hide a certain view whenever the bottom-sheet is expanded, but the code that checks the state only gets executed one time. How do i make the program constantly check the state of the bottom-sheet and hide the view(grid_opt) whenever the bottom sheet is expanded.

class dashboard : AppCompatActivity() {
    private lateinit var bottomSheetBehavior: BottomSheetBehavior<ConstraintLayout>

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.dashboard_main)

        bottomSheetBehavior = BottomSheetBehavior.from(persistent_bottom_sheet)
        bottomSheetBehavior.state = STATE_EXPANDED
        if ( bottomSheetBehavior.state == STATE_EXPANDED){
            grid_opt.isVisible = false;
        }else if(bottomSheetBehavior.state== STATE_COLLAPSED){
            grid_opt.isVisible= true;
        }

Solution

This can be done by adding bottomsheetcallback

 bottomSheetBehavior.addBottomSheetCallback(object :
            BottomSheetBehavior.BottomSheetCallback() {
            override fun onSlide(bottomSheet: View, slideOffset: Float) {
            }

            override fun onStateChanged(bottomSheet: View, newState: Int) {
                grid_opt.isVisible = when (newState) {
                    BottomSheetBehavior.STATE_EXPANDED -> false
                    BottomSheetBehavior.STATE_COLLAPSED -> true
                    else -> false
                }
            }
        })

Answered By - Abinab Dangi