Spinner's onItemSelected callback called twice after a rotation if non-zero position is selected

Question

When I create my activity, I setup a Spinner, assigning it a listener and an initial value. I know that the onItemSelected callback is called automatically during a

Answer 1

Just use setSelection(#, false) before setting the listener:

@Override
protected void onCreate(Bundle savedInstanceState) {
    ...
    spinner.setSelection(2, false);
    spinner.setOnItemSelectedListener(this);
}

The key is the second parameter. It says to not animate the transition, executing the action immediately and preventing onItemSelected from being fired twice, because a call is already made by the system.

Answer 2

In general, there seem to be many events that trigger the onItemSelected call, and it is difficult to keep track of all of them. This solution allows you to only respond to user-initiated changes using an OnTouchListener.

Create your listener for the spinner:

public class SpinnerInteractionListener implements AdapterView.OnItemSelectedListener, View.OnTouchListener {

    boolean userSelect = false;

    @Override
    public boolean onTouch(View v, MotionEvent event) {
        userSelect = true;
        return false;
    }

    @Override
    public void onItemSelected(AdapterView<?> parent, View view, int pos, long id) {
        if (userSelect) { 
            // Your selection handling code here
            userSelect = false;
        }
    }

}

Add the listener to the spinner as both an OnItemSelectedListener and an OnTouchListener:

SpinnerInteractionListener listener = new SpinnerInteractionListener();
mSpinnerView.setOnTouchListener(listener);
mSpinnerView.setOnItemSelectedListener(listener);