Game.Java

import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.view.MotionEvent;
import android.view.SurfaceHolder;
import android.view.SurfaceView;

public class GameView extends SurfaceView implements SurfaceHolder.Callback {
    private GameThread gameThread;
    private float circleX, circleY;
    private Paint paint;

    public GameView(Context context) {
        super(context);
        getHolder().addCallback(this);

        circleX = 100;
        circleY = 100;
        paint = new Paint();
        paint.setColor(Color.RED);

        gameThread = new GameThread(getHolder(), this);
        setFocusable(true);
    }

    @Override
    public void surfaceCreated(SurfaceHolder holder) {
        gameThread.setRunning(true);
        gameThread.start();
    }

    @Override
    public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) {
    }

    @Override
    public void surfaceDestroyed(SurfaceHolder holder) {
        boolean retry = true;
        gameThread.setRunning(false);
        while (retry) {
            try {
                gameThread.join();
                retry = false;
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
        }
    }

    @Override
    public boolean onTouchEvent(MotionEvent event) {
        circleX = event.getX();
        circleY = event.getY();
        return true;
    }

    @Override
    protected void onDraw(Canvas canvas) {
        canvas.drawColor(Color.WHITE);
        canvas.drawCircle(circleX, circleY, 50, paint);
    }
}

import android.graphics.Canvas;
import android.view.SurfaceHolder;

public class GameThread extends Thread {
    private SurfaceHolder surfaceHolder;
    private GameView gameView;
    private boolean running;

    public GameThread(SurfaceHolder surfaceHolder, GameView gameView) {
        this.surfaceHolder = surfaceHolder;
        this.gameView = gameView;
    }

    public void setRunning(boolean running) {
        this.running = running;
    }

    @Override
    public void run() {
        while (running) {
            Canvas canvas = null;
            try {
                canvas = surfaceHolder.lockCanvas();
                synchronized (surfaceHolder) {
                    gameView.onDraw(canvas);
                }
            } finally {
                if (canvas != null) {
                    surfaceHolder.unlockCanvasAndPost(canvas);
                }
            }
        }
    }
}