In Android EditText, how to force writing uppercase?

Question

In my Android application I have different EditText where the user can enter information. But I need to force user to write in uppercase letters. Do you know a

Answer 1

Simple kotlin realization

fun EditText.onlyUppercase() {
    inputType = InputType.TYPE_CLASS_TEXT or InputType.TYPE_TEXT_FLAG_CAP_CHARACTERS
    filters = arrayOf(InputFilter.AllCaps())
}

PS it seems that filters is always empty initially