Material Exposed Dropdown Menu OnItemSelectedListener not being called

Question

I have an ExposedDropdownMenu implemented in my app, and while hamfisted, it gets the job done and I'm able to style it how I want it to look. On my country "spinner", i want the list of states to change to provinces if canada is selected, then be populated with a list of canadian provinces. When my "spinner" was an actual Spinner, OnItemSelectedListener worked flawlessly, however, it no longer is changing back and forth now that I've implemented the "spinner" as an EDM

Here is my code:

// get country spinner values and change state/zip options depending on country selected
val countryAdapter = MaterialSpinnerAdapter<String>(it, R.layout.material_spinner_item, it.resources.getStringArray(R.array.country))
country_dropdown.setAdapter(countryAdapter)
country_dropdown.onItemSelectedListener = object : AdapterView.OnItemSelectedListener {
                override fun onItemSelected(
                    parent: AdapterView<*>?,
                    view: View?,
                    position: Int,
                    id: Long
                ) {
                    displayStatesForSelectedCountry(position)
                }

                override fun onNothingSelected(parent: AdapterView<*>?) {
                    displayDefaultStatesList()
                }
}

    private fun displayStatesForSelectedCountry(position: Int) {
        context?.let {
            val canadaAdapter = MaterialSpinnerAdapter<String>(it, R.layout.material_spinner_item, it.resources.getStringArray(R.array.states_of_canada))

            when(position) {
                1 -> {
                    displayDefaultStatesList()
                }
                2 -> {
                    state_dropdown.setAdapter(canadaAdapter)
                    enrollment_zip_code.hint = it.resources.getString(R.string.enrollment_hint_postal_code)
                    enrollment_zip_code.editText?.inputType = InputType.TYPE_CLASS_TEXT
                }
                else -> displayDefaultStatesList()
            }
        }
    }

Thinking that maybe the behaviour has changed, I attempted to implement the OnItemClickedListener instead:

country_dropdown.setOnItemClickListener { parent: AdapterView<*>?,
                                                      view: View?,position:
                                                      Int,id: Long ->
                displayStatesForSelectedCountry(position)
            }

No dice. I know that the listener(s) are not being called at all because at the very least, the zipcode hint would change to postal code, however, it does not. What am I doing wrong here? should I not be using the position? if not, why not? MaterialSpinnerAdapter is just a subclass of ArrayAdapter to prevent filtering when I dont want it to filter, but i should be able to reliably use the position to determine what to show.

Answer 1

It occurred to me that its a type of EditText, so this works:

            country_dropdown.addTextChangedListener(object: TextWatcher {
                override fun afterTextChanged(s: Editable?) {
                }

                override fun beforeTextChanged(
                    s: CharSequence?,
                    start: Int,
                    count: Int,
                    after: Int
                ) {
                }

                override fun onTextChanged(s: CharSequence?, start: Int, before: Int, count: Int) {
                    displayStatesForSelectedCountry(s.toString())
                    viewModel.country.value = s.toString()
                }
            })