Android: Returning values from a custom Dialog

Context:

Cases which involve using a custom dialog to capture user input, may require the captured data to be passed back to the displaying activity. The following describes exactly this… how to pass back data from a custom dialog to the displaying activity.

ps – by custom dialog we mean a custom class that ‘extends Dialog‘.

Solution:

Step 1 – Define custom interface

 // step 1 - to return values from dialog
 public interface OnFooEventListener {
     public void fooEvent(int fieldOne, int fieldTwo);
 }

Step 2 – Declare the above interface as a field member

 // step 2 - to return values from dialog
 private OnFooEventListener onFooEventListener;

Step 3 – Add it to the custom dialog constructor

 // step 3 - to return values from dialog
 public FooEventDialog(Context context, OnFooEventListener onFooEventListener)
 {
     super(context);
     this.context = context;

     this.onFooEventListener = onFooEventListener;
 }

Step 4 – Call it within the view object’s event listener, (in this case an ‘ok’ button)

 Button btnOk = (Button) findViewById(R.id.btnSet);
 btnOk.setOnClickListener( new Button.OnClickListener()
 {
     @Override
     public void onClick(View v) {

         // step 4 - to return values from dialog
         onFooEventListener.fooEvent(fieldOne, fieldTwo);
         dismiss();
     }
 });

Overview – So the class should look something like the following

public class FooEventDialog extends Dialog
{

    // step 1
    public interface OnFooEventListener {
        public void fooEvent(int fieldOne, int fieldTwo);
    }

    // step 2
    private OnFooEventListener onFooEventListener;

    // Other member fields
    ...

    // step 3
    public FooEventDialog(Context context, OnFooEventListener onFooEventListener)
    { ... }

    @Override
    public void onCreate(Bundle savedInstanceState)
    {
         // other stuff
         ...

        Button btnOk = (Button) findViewById(R.id.btnSet);
        btnOk.setOnClickListener( new Button.OnClickListener()
        {
            @Override
             public void onClick(View v) {

                 // step 4 - to return values from dialog
                 onFooEventListener.fooEvent(fieldOne, fieldTwo);
                 dismiss();
             }
         });
     }
}

… That’s all there is to it.

Wa’Allahu A’lam !

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