Universal Android Confirmation Dialog

AppCfg.kt

object AppCfg {
    const val CONFIRMATION_PARAM = "resultKey"
    const val CONFIRMATION_TITLE = "title"
    const val CONFIRMATION_TEXT = "content"
    const val CONFIRMATION_POSITIVE = "positiveLabel"
    const val CONFIRMATION_NEGATIVE = "negativeLabel"
    const val CONFIRMATION_POSITIVE_ICON = "positiveIcon"
  
    const val IS_DELETED = "IS_DELETED"
    const val IS_EXPORTED = "IS_EXPORTED"
}

ConfirmationDialog.kt

class ConfirmationDialog : BaseDialogFragment(), View.OnClickListener {

    private val TAG = ConfirmationDialog::class.java.canonicalName

    override fun onCreateDialog(savedInstanceState: Bundle?): Dialog {

        val view = requireActivity().layoutInflater.inflate(R.layout.dialog_confirmation, null)

        val builder = MaterialAlertDialogBuilder(requireContext())
        builder.setView(view)

        bindText()

        val dialog: Dialog = builder.create()
        dialog.requestWindowFeature(Window.FEATURE_NO_TITLE)
        // dialog.window?.setBackgroundDrawable(ColorDrawable(Color.TRANSPARENT))
        return dialog

    }

    private fun bindText() {
        with(dialog!!) {
            findViewById<TextView>(R.id.titleConfirmation).text = arguments?.getString(AppCfg.CONFIRMATION_TITLE)
            findViewById<TextView>(R.id.textConfirmation).let {
                it.isVisible = arguments?.getString(AppCfg.CONFIRMATION_TEXT) != null
                it.text = arguments?.getString(AppCfg.CONFIRMATION_TEXT)
            }
            findViewById<MaterialButton>(R.id.buttonConfirmation).let {
                it.text = arguments?.getString(AppCfg.CONFIRMATION_POSITIVE) ?: getString(R.string.btn_delete)
                it.setOnClickListener(this@ConfirmationDialog)
            }
            findViewById<MaterialButton>(R.id.buttonCancelConfirmation).let { btn ->
                btn.text = arguments?.getString(AppCfg.CONFIRMATION_NEGATIVE) ?: getString(R.string.btn_cancel)
                arguments?.getInt(AppCfg.CONFIRMATION_POSITIVE_ICON)?.let {
                    if (it > 0) btn.setIconResource(it)
                }
                btn.setOnClickListener(this@ConfirmationDialog)
            }
        }
    }

    override fun onClick(v: View?) {
        if (BuildConfig.DEBUG) Log.e(TAG, "Sending results back: " + arguments?.getString(AppCfg.CONFIRMATION_PARAM))
        sendResult(key = arguments?.getString(AppCfg.CONFIRMATION_PARAM) ?: "", v?.id == R.id.buttonConfirmation)
    }
}

dialog_confirmation.xml

<?xml version="1.0" encoding="utf-8"?>
<androidx.appcompat.widget.LinearLayoutCompat
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:id="@+id/confirmationLayout"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:orientation="vertical">

    <TextView
        android:id="@+id/titleConfirmation"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_margin="16dp"
        android:textAppearance="@style/TextAppearance.MaterialComponents.Headline5"
        android:text="Are you sure?" />

    <TextView
        android:id="@+id/textConfirmation"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_margin="16dp"
        android:textSize="18sp"
        android:text="Are you sure you want to do it?" />

    <androidx.appcompat.widget.LinearLayoutCompat
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_margin="16dp"
        android:orientation="horizontal">

        <Button
            android:id="@+id/buttonCancelConfirmation"
            android:layout_width="0dp"
            android:layout_height="wrap_content"
            android:layout_weight="1"
            android:elevation="0dp"
            android:layout_marginEnd="16dp"
            app:icon="@drawable/ic_close_circle_outline"
            android:text="cancel"
            style="@style/Widget.MaterialComponents.Button.OutlinedButton.Icon" />

        <com.google.android.material.button.MaterialButton
            android:id="@+id/buttonConfirmation"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            app:iconGravity="end"
            app:icon="@drawable/ic_trash_can_outline"
            android:text="confirm" />

    </androidx.appcompat.widget.LinearLayoutCompat>

</androidx.appcompat.widget.LinearLayoutCompat>

MyScreenFragment.kt

    override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
        super.onViewCreated(view, savedInstanceState)
        
        getResult<Boolean>(AppCfg.IS_DELETED) { deleteItem(it) }
        getResult<Boolean>(AppCfg.IS_EXPORTED) { exportItem(it) }
        
    }
    
    fun onDeleteButtonClick() {
        navigate(R.id.action_global_confirmationDialog, Bundle().also {
            it.putString(AppCfg.CONFIRMATION_PARAM, AppCfg.IS_DELETED)
            it.putString(AppCfg.CONFIRMATION_TITLE, "Delete this contanct?")
            it.putString(AppCfg.CONFIRMATION_TEXT, "Deleting the contact will also remove their images, history.")
            it.putString(AppCfg.CONFIRMATION_POSITIVE, "ok")
            it.putString(AppCfg.CONFIRMATION_NEGATIVE, "nah")
            it.putInt(AppCfg.CONFIRMATION_POSITIVE_ICON, R.drawable.ic_alert_outlined)
        })
    }
    
    fun deleteItem(how: Boolean) {
        if (how) Log.e("ConfirmedActionDialog", "Confirmed, may proceed")
        else Log.e("ConfirmedActionDialog", "Cancelled, forget it")
    }
    
    fun exportItem(how: Boolean) {
        // see above
    }

nav_graph.xml

    <action
        android:id="@+id/action_global_confirmationDialog"
        app:destination="@id/confirmationDialog" />

    <dialog
        android:id="@+id/confirmationDialog"
        android:name="com.example.package.ConfirmationDialog"
        android:label="dialog_confirmation"
        tools:layout="@layout/dialog_confirmation">
        <argument
            android:name="resultKey"
            app:argType="string" />
        <argument
            android:name="title"
            app:argType="string" />
        <argument
            android:name="content"
            app:argType="string"
            app:nullable="true" />
        <argument
            android:name="positiveLabel"
            app:argType="string"
            app:nullable="true" />
        <argument
            android:name="negativeLabel"
            app:argType="string"
            app:nullable="true" />
        <argument
            android:name="positiveIcon"
            app:argType="integer"
            android:defaultValue="0" />
    </dialog>

UtilitiesFragment.kt

fun <T> Fragment.sendResult(key: String, value: T) {
    with(findNavController()) {
        previousBackStackEntry?.savedStateHandle?.set(key, value)
        // to handle screen rotation, otherwise getResult with ID works
        currentBackStackEntry?.savedStateHandle?.set(key, value)
        navigateUp()
    }
}

// cannot handle screen rotation with opened dialog
fun <T> Fragment.getResult(key: String, observer: Observer<T>) {
    val savedStateHandle = findNavController().currentBackStackEntry?.savedStateHandle ?: return
    savedStateHandle.getLiveData<T>(key).observe(viewLifecycleOwner, observer)
}

fun <T> DialogFragment.getResult(key: String, observer: Observer<T>) {
    val savedStateHandle = findNavController().currentBackStackEntry?.savedStateHandle ?: return
    savedStateHandle.getLiveData<T>(key).observe(this, observer)
}

// entry = R.id.myScreen from nav xml map
fun <T> Fragment.getResult(entry: Int, key: String, observer: Observer<T>) {
    val savedStateHandle = findNavController().getBackStackEntry(entry).savedStateHandle ?: return
    savedStateHandle.getLiveData<T>(key).observe(viewLifecycleOwner, observer)
}

Notice the click listeners in the dialog - there is a potential for memory leaks. Dispose them on dismiss maybe.