set view height when show soft keyboard is open

BaseSectionFragment.kt

   override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?, savedInstanceState: Bundle?): View? {
        mView = inflater.inflate(R.layout.fragment_base_section, container, false)
        KeyboardUtil(requireActivity(), mView.coordinatorLayout)
        return mView
    }

KeyboardUtil.kt

import android.app.Activity
import android.graphics.Rect
import android.view.View
import android.view.ViewTreeObserver
import android.view.inputmethod.InputMethodManager

class KeyboardUtil(act: Activity, private val contentView: View) {

    private val decorView: View = act.window.decorView

    private var negativeHeight = 0

    //a small helper to allow showing the editText focus
    private var onGlobalLayoutListener: ViewTreeObserver.OnGlobalLayoutListener =
        ViewTreeObserver.OnGlobalLayoutListener {

            val r = Rect()
            //r will be populated with the coordinates of your view that area still visible.
            decorView.getWindowVisibleDisplayFrame(r)

            //get screen height and calculate the difference with the useable area from the r
            val height = decorView.context.resources.displayMetrics.heightPixels
            val diff = height - r.bottom

            //if it could be a keyboard add the padding to the view
            if (diff != 0) {
                // if the use-able screen height differs from the total screen height we assume that it shows a keyboard now
                //check if the padding is 0 (if yes set the padding for the keyboard)
                if (contentView.paddingBottom != diff) {

                    if(negativeHeight==0 && diff<0){
                        negativeHeight = -(diff)
                    }

                    contentView.setPadding(0, 0, 0, diff+negativeHeight)
                    //set the padding of the contentView for the keyboard
                }
            } else {
                negativeHeight = 0
                //check if the padding is != 0 (if yes reset the padding)
                if (contentView.paddingBottom != 0) {
                    //reset the padding of the contentView
                    contentView.setPadding(0, 0, 0, 0)
                }
            }
        }

    init {
        //only required on newer android versions. it was working on API level 19
            decorView.viewTreeObserver.addOnGlobalLayoutListener(onGlobalLayoutListener)
    }

    companion object {


        /**
         * Helper to hide the keyboard
         *
         * @param act
         */
        fun hideKeyboard(act: Activity?) {
            if (act != null && act.currentFocus != null) {
                val inputMethodManager = act.getSystemService(Activity.INPUT_METHOD_SERVICE) as InputMethodManager
                inputMethodManager.hideSoftInputFromWindow(act.currentFocus!!.windowToken, 0)
            }
        }
    }
}