Set time variable on Back button

Question

You guys, good night. I need a little help, I have the following code. Because I need to stop Thread when the back button is clicked.

private void timeGame() {

    t = new Timer();
    t.scheduleAtFixedRate(new TimerTask() {
        @Override
        public void run() {
            //runOnUiThread
            runOnUiThread(new Runnable() {
                @SuppressLint("SetTextI18n")
                @Override
                public void run() {

                    if (timeCounter > 0){

                        timeCounter--;
                       textoTime.setText((Integer.toString((timeCounter))));

                    }else{

                        t.cancel();
                        startActivity(new Intent(QuestionsSolo.this, GameOver.class));
                        QuestionsSolo.this.finish();

                    }


                    }

            });

        }
    }, 1000, 1000);

}

@Override
public void onBackPressed() {
//funcionando, ficou assim.    
t.cancel();
startActivity(new Intent(QuestionsSolo.this, TypeFragmentSolo.class));
}

}

Answer 1

Option 1

You can use a volatile as an attribute for control.

private volatile boolean run = true;

...
private void timeGame() {
 ...

   if (timeCounter > 0 && run){ // <-- atributo de controle

      timeCounter--;
      textoTime.setText((Integer.toString((timeCounter))));

   }else{

      t.cancel();// <-- cancela se o atributo for false
      startActivity(new Intent(QuestionsSolo.this, GameOver.class));
      QuestionsSolo.this.finish();

    }

Then in the onBackPressed() you change:

@Override
public void onBackPressed() {
    run = false;
}

This way it will cancel when the attribute run for false.

Option 2

Instead of putting the Timer within the function timeGame()

private void timeGame() {
      final Timer t = new Timer();

...

You insert this Timer as a class attribute:

Timer t;

and in the function you change to:

 private void timeGame() {
      t = new Timer();

  ...

With this you will be able to cancel within the onBackPressed():

@Override
public void onBackPressed() {
   t.cancel();
}

I haven’t tested any of them, but I believe both options work.