Question

Well… I am trying to create an application using the TTS Engine.

I can already make it, work, no problem. However I need my buttons to be dinamic, they will come from a database.

So far you guys have helped me a lot, since now I can do it thanks to the tips I got from you guys.

Well.. now I am stuck again.

Every new button that I create I attach an OnClickListener so it can start the TTS and speak something.

However it’s an inner method, so, when I try to run the code below, it gives me a NullPointerException when it tries to “speak” using the TTS. I know the TTS object is out of context, so, How can I solve this?

Below the code. It’s a little big since I wanted to include everything:

PLEASE JUMP TO THE “HERE IS MY PROBLEM!!!” comment so you guys can see exactly where my problem is. I know where it is, but I don’t know how to solve it =(

Any help is appreciatted! =)

public class LivoxTesteActivity extends Activity implements OnInitListener{
    /** Called when the activity is first created. */
    private int MY_DATA_CHECK_CODE = 0;
    public TextToSpeech tts;


    @Override
    public void onCreate(Bundle savedInstanceState) {

    super.onCreate(savedInstanceState);
    requestWindowFeature(Window.FEATURE_NO_TITLE); 
    getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN, 
            WindowManager.LayoutParams.FLAG_FULLSCREEN);  
    setContentView(R.layout.main);


    LinearLayout lgeral = new LinearLayout (this);
    lgeral.setOrientation(LinearLayout.VERTICAL);
    lgeral.setLayoutParams(new LinearLayout.LayoutParams(LayoutParams.FILL_PARENT, LayoutParams.FILL_PARENT, 1f));

    String array[][] = {{"Comer","eat", "Eu quero comer", "1"},
            {"Abraço","hug", "Eu quero um abraço", "2"},
            {"Assustado","afraid", "Eu estou com medo", "3"},
            {"Beber","drink", "Eu quero beber", "4"}};
    int x = array.length;

    int qtdeLinhas = 2;
    for (int j = 0; j < qtdeLinhas; j++) {        

        LinearLayout l1 = new LinearLayout (this);
        l1.setOrientation(LinearLayout.HORIZONTAL);
        l1.setLayoutParams(new LinearLayout.LayoutParams(LayoutParams.FILL_PARENT, LayoutParams.FILL_PARENT, 1f));

        FrameLayout fl;
        for (int i = 0; i < array.length; i++) {

            fl = (FrameLayout)LayoutInflater.from(getBaseContext()).inflate(R.layout.framelayoutstyle, l1, false);

            TextView textoEscrito;
            textoEscrito = (TextView)LayoutInflater.from(getBaseContext()).inflate(R.layout.textviewstyle, fl, false);

            textoEscrito.setText(array[i][0]);

            final String texto = textoEscrito.getText().toString();        
            final String textoFalar = array[i][2];

            ImageButton btn;
            btn = (ImageButton)LayoutInflater.from(getBaseContext()).inflate(R.layout.imagebuttonstyle, fl, false);

            btn.setImageResource(this.getResources().getIdentifier("drawable/" + array[i][1], null, this.getPackageName()));


            btn.setOnClickListener(new Button.OnClickListener(){
                public void onClick (View v){


                    Toast.makeText(getBaseContext(), texto, Toast.LENGTH_SHORT).show();
                    //*******************************
                    //HERE IS MY PROBLEM!!!
                    //*******************************
                    tts.speak(txtFl, TextToSpeech.QUEUE_ADD, null);
                    //*******************************
                    //WHEN I TRY TO RUN THE ABOVE IT GIVES A NULLPOINTEREXCEPTION!!!
                    //*******************************



                }

            });


            fl.addView(btn);
            fl.addView(textoEscrito);

            l1.addView(fl);
        }

        lgeral.addView(l1);
    }

    setContentView(lgeral);        

}


protected void onActivityResult(int requestCode, int resultCode, Intent data) {
    if (requestCode == MY_DATA_CHECK_CODE) {
        if (resultCode == TextToSpeech.Engine.CHECK_VOICE_DATA_PASS) {
            // success, create the TTS instance
            tts = new TextToSpeech(this, this);
        }
        else {
            // missing data, install it
            Intent installIntent = new Intent();
            installIntent.setAction(TextToSpeech.Engine.ACTION_INSTALL_TTS_DATA);
            startActivity(installIntent);
        }
    }

}
@Override
public void onInit(int status) {       
    if (status == TextToSpeech.SUCCESS) {
    }
    else if (status == TextToSpeech.ERROR) {
    }
}


@Override
public void onDestroy() {
if (tts != null) {
tts.stop();
tts.shutdown();
}
super.onDestroy();
} 

}

By the way… the method Toast.makeText(getBaseContext(), texto, Toast.LENGTH_SHORT).show(); works fine. I believe that’s because the Toast is a static class.

So, maybe the solution is to create a static class with the method to speak? Ideas? How can I do it?

Answer 1

Make sure that both onActivityResult and onInit are invoked before you synthesize speech. If NullPointerException is what you’re getting, the most likely cause is that by the time the button is clicked, the tts object has not been constructed yet.

The right approach is to set up a queue of phrases to speak (like, an ArrayList<String>), and once the TTS is initialized (i. e. in the SUCCESS branch of onInit), start speaking.

EDIT: now that I look at your code… Where are you invoking any activities that would cause an onActivityResult call? The dev guide suggests doing the following as a part of init process:

Intent checkIntent = new Intent();
checkIntent.setAction(TextToSpeech.Engine.ACTION_CHECK_TTS_DATA);
startActivityForResult(checkIntent, MY_DATA_CHECK_CODE);

There’s nothing in the pasted snippet to that effect.