Callback from Spinner Class to FragmentActivity

Question

I have to know the click event from the spinner in the Activity. The OnClick Method of the MultiSelectionSpinner Class gets called, but I have no idea how to create a callback method for the Activity. Following is the Spinner Class and the Activity.

public class MultiSelectionSpinner extends Spinner implements
        OnMultiChoiceClickListener {
    String[] _items = null;
    boolean[] mSelection = null;

    ArrayAdapter<String> simple_adapter;

    public MultiSelectionSpinner(Context context) {
        super(context);

        simple_adapter = new ArrayAdapter<String>(context,
                android.R.layout.simple_spinner_item);
        super.setAdapter(simple_adapter);
    }

    public MultiSelectionSpinner(Context context, AttributeSet attrs) {
        super(context, attrs);

        simple_adapter = new ArrayAdapter<String>(context,
                android.R.layout.simple_spinner_item);
        super.setAdapter(simple_adapter);
    }

    public void onClick(DialogInterface dialog, int which, boolean isChecked) {
        if (mSelection != null && which < mSelection.length) {
            mSelection[which] = isChecked;

            simple_adapter.clear();
            simple_adapter.add(buildSelectedItemString());


        } else {
            throw new IllegalArgumentException(
                    "Argument 'which' is out of bounds.");
        }
    }




public class mainActivity extends FragmentActivity

// Thats the spinner
MultiSelectionSpinner spinner;

public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main); 

// Here I load the spinner with the Names       
spinner = (MultiSelectionSpinner) findViewById(R.id.spinner);
spinner.setItems(Names);

score 1 · Accepted Answer · answered May 03 '15 at 17:45

The most straightforward way is to create another listener interface in MultiSelectionSpinner which your Activity implements.

public interface MySpinnerListener{
   public void onItemClicked(int which);
}

MySpinnerListener listener;
public void setListener(MySpinnerListener  listener) {      
    this.listener = listener;       
}

public void onClick(int which,...){
   listener.onClick(which);
   ...
}

Then implement the callback in your Activity

spinner = (MultiSelectionSpinner) findViewById(R.id.spinner);
spinner.setListener(new MultiSelectionSpinner.MySpinnerListener(){

    @Override
    public void onClick(int which){
        // callback 
    }   
});

Great trank you very much! – user1390816 May 03 '15 at 18:22 — user1390816, May 03 '15 at 18:22

Callback from Spinner Class to FragmentActivity

1 Answers1