Show a pop-up dialog at the end of the game on SurfaceView

Question

I want to pop up a dialog box when the user completes the game to show his points and time. I read about the runOnUiThread and I tried to implement the solution in my code, but is not working. I get the following error:

"Can't create handler inside thread that has not called Looper.prepare()"

.

I have a bool variable called gameCompleted in my SurfaceView class, when this becomes true I call the method showDialogGameCompleted() which is implemented in the Activity class. Where am I wrong?

My activity class:

public class Canvastutorial extends Activity {

final Context context = this;
Dialog dialog;

/** Called when the activity is first created. */
@TargetApi(Build.VERSION_CODES.HONEYCOMB_MR2)
@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.play_layout);       
}    

// THE METHOD I CALL FROM MY SURFACEVIEW CLASS IN ORDER TO SHOW THE DIALOG
public void showDialogGameCompleted()
{           
    dialog= new Dialog(context);
    dialog.setContentView(R.layout.custom);
    dialog.setTitle("PUZZLE COMPLETED!");

        // set the custom dialog components - text, image and button
        TextView text = (TextView) dialog.findViewById(R.id.text);
        text.setText("Congratulations!\nPoints: \nMoves: \nTime: ");
        ImageView image = (ImageView) dialog.findViewById(R.id.image);
        image.setImageResource(R.drawable.cup);

        Button dialogButton = (Button) dialog.findViewById(R.id.dialogButtonOK);
        // if button is clicked, close the custom dialog
        dialogButton.setOnClickListener(new OnClickListener() {
            @Override
            public void onClick(View v) {
                dialog.dismiss();
            }
        });

        Canvastutorial.this.runOnUiThread(new Runnable() {
            public void run() {
                dialog.show();
            }
        });       
}

My SurfaceView class:

public class MySurfaceView extends SurfaceView implements SurfaceHolder.Callback{
private CanvasThread canvasthread;
private Canvastutorial canvastutorial= new Canvastutorial();



public MySurfaceView(Context context, AttributeSet attrs) {
    super(context, attrs); 
    // TODO Auto-generated constructor stub

    getHolder().addCallback(this);
    canvasthread = new CanvasThread(getHolder(), this);
    setFocusable(true);     
}

 public MySurfaceView(Context context) {
       super(context);
        getHolder().addCallback(this);
        canvasthread = new CanvasThread(getHolder(), this);
        setFocusable(true);
    }


@Override
public void onDraw(Canvas canvas) {

    if(canvas!=null)
    {

        switch (w)
        {
            case MENU:                  
                //menu stuff
                break;

            case GAME:

                // WHEN THE GAME IS COMPLETED I CALL THE
                 //showDialogGameCompleted METHOD WHICH IS IMPLEMENTED IN MY ACTIVITY CLASS
                if(gameCompleted)
                {
                    gameCompleted=false;
                    canvastutorial.showDialogGameCompleted();
                }                   
            break;
        }
    }
}    

@Override
public void surfaceChanged(SurfaceHolder holder, int format, int width,
        int height) {
    // TODO Auto-generated method stub

}
@Override
public void surfaceCreated(SurfaceHolder holder) {      

    canvasthread.setRunning(true);
    canvasthread.start();


}
@Override
public void surfaceDestroyed(SurfaceHolder holder) {
    // TODO Auto-generated method stub
    boolean retry = true;
    canvasthread.setRunning(false);
    while (retry) {
        try {
            canvasthread.join();
            retry = false;
        } catch (InterruptedException e) {
            // we will try it again and again...
        }
    }

}

My Thread class:

public class CanvasThread extends Thread {
private SurfaceHolder _surfaceHolder;
private MySurfaceView _mySurfaceView;
private boolean _run = false;

public CanvasThread(SurfaceHolder surfaceHolder, MySurfaceView mySurfaceView) {
    _surfaceHolder = surfaceHolder;
    _mySurfaceView = mySurfaceView;
}

public void setRunning(boolean run) {
    _run = run;
}

@Override
public void run() {
    Canvas c;
    while (_run)
    {
        c = null;
        try
        {
            c = _surfaceHolder.lockCanvas(null);
            synchronized (_surfaceHolder)
            {
                _mySurfaceView.onDraw(c);
            }
        }
        finally
        {
            // do this in a finally so that if an exception is thrown
            // during the above, we don't leave the Surface in an
            // inconsistent state
            if (c != null)
                _surfaceHolder.unlockCanvasAndPost(c);
        }
    }
}
}

You need to do *all* UI operations on the UI thread. Execute the entire showDialogGameCompleted() method with runOnUiThread(), not just dialog.show(). — fadden, Mar 20 '14 at 14:53
I tried that, but I'm getting a NullPointerException at android.content.ContextWrapper.getApplicationInfo. Is anything wrong in the way I pass the context to my dialog variable? — user3121071, Mar 21 '14 at 01:22
this is a simple example for a handler. http://stackoverflow.com/questions/22548764/android-drawing-on-thread/22551933#22551933 — ravindu1024, Mar 21 '14 at 06:49

score 2 · Answer 1 · edited May 23 '17 at 10:26

2

You can not call that from your thread. Because it is still working. I think you need to use Handler. Look up this answer. Maybe it can help you. https://stackoverflow.com/a/16886486/3077964

edited May 23 '17 at 10:26

Community

1
1

answered Mar 20 '14 at 08:21

Hasan Güner

53
7

Could you provide an example about the Handler? I mean what methods should be implemented and where? – user3121071 Mar 21 '14 at 02:37

Show a pop-up dialog at the end of the game on SurfaceView

1 Answers1