Receive Listener onResults() from a different activity

Question

I'm developing an App with SpeechRecognizer. I will use it in different activities for different uses and It's a bit dirty add the same code all time to different classes. So I moved my custom RecognitionListener to a new class. In that way I just initialize it when I want from my activities. But I can´t find a way to receive the result of the listener (in this case, an ArrayList of possible values for the speech recognized) in my current activity to use it.

I have tried to implement it through an interface, but I think that I did it in a wrong way. My Listener code is this:

public class SpeechRecognitionListener implements RecognitionListener
{
    private final String TAG = "SpeechRecognitionListener";
private Intent mSpeechRecognizerIntent;
private SpeechRecognizer mSpeechRecognizer;

public SpeechRecognitionListener(Intent speechRecognizerIntent, SpeechRecognizer speechRecognizer ) {
    mSpeechRecognizerIntent = speechRecognizerIntent;
    mSpeechRecognizer = speechRecognizer;
}

@Override
public void onBeginningOfSpeech()
{
    //Log.d(TAG, "onBeginingOfSpeech");
}

@Override
public void onBufferReceived(byte[] buffer)
{

}

@Override
public void onEndOfSpeech()
{
    //Log.d(TAG, "onEndOfSpeech");
}

@Override
public void onError(int error)
{
    mSpeechRecognizer.startListening(mSpeechRecognizerIntent);

    //Log.d(TAG, "error = " + error);
}

@Override
public void onEvent(int eventType, Bundle params)
{

}

@Override
public void onPartialResults(Bundle partialResults)
{

}

@Override
public void onReadyForSpeech(Bundle params)
{
    Log.d(TAG, "onReadyForSpeech"); //$NON-NLS-1$
}

@Override
public void onResults(Bundle results)
{
    //I want to recieve this array in my main activity
    ArrayList<String> matches = results.getStringArrayList(SpeechRecognizer.RESULTS_RECOGNITION);

}

@Override
public void onRmsChanged(float rmsdB)
{
}
}

I just want to receive the onResult() array in my current activity to work with it.

Answer 1

Try to define an interface first:

public interface RecognitionCallback
{
   abstract void onRecoginitionFinished(ArrayList<String> matches);
}

Now let your activity that needs to be called back implement this interface. For example:

public class MainActivity extends AppCompatActivity implements RecognitionCallback {

  ...

  public void onRecognitionFinished(ArrayList<String> matches)
  {
     //do your things with the data
  }

}

Also add some properties of SpeechRecognitionListener class:

public class SpeechRecognitionListener implements RecognitionListener
{
    private final String TAG = "SpeechRecognitionListener";
    private Intent mSpeechRecognizerIntent;
    private SpeechRecognizer mSpeechRecognizer;
    private RecognitionCallback mCallback

    public SpeechRecognitionListener(Intent speechRecognizerIntent, SpeechRecognizer speechRecognizer, RecognitionCallback callback ) {
       mSpeechRecognizerIntent = speechRecognizerIntent;
       mSpeechRecognizer = speechRecognizer;
       mCallback = callback;

    ...

    public void onResults(Bundle results)
    {

       ArrayList<String> matches = results.getStringArrayList(SpeechRecognizer.RESULTS_RECOGNITION);
       mCallback.onRecognitionFinished(matches);
    }
}    

And finally in your activity where you need to get called back write this:

   SpeechRecognitionListener listener = new SpeechRecognitionLinstner(intent,recognizer,this);