Question

Here is my main:

@Override
public void onCreate(Bundle savedInstanceState) {

    super.onCreate(savedInstanceState);

    setContentView(R.layout.main);

    LinearLayout layout = (LinearLayout) findViewById(R.id.mainView);
    TextView text=  (TextView) findViewById(R.id.text);
    text.setText("This is a Test!");

    firstCircle first = new firstCircle(this);
    secondCircle second = new secondCircle(this);
    layout.addView(first);
    layout.addView(second);

}

Here is my firstCircleClass:

public class firstCircle extends SurfaceView implements SurfaceHolder.Callback {

private firstThread _firstThread;
private secondThread _secondThread;
private SurfaceHolder surfaceHolder;


public firstCircle (Context context, AttributeSet attrs){
    super(context,attrs);
    getHolder().addCallback(this);
    setFocusable(true);
    _firstThread= new firstThread(getHolder(),this);

}

public firstCircle (Context context){
    super(context);
    getHolder().addCallback(this);
    setFocusable(true);
    _firstThread= new firstThread(getHolder(),this);

}

@Override
public void onDraw(Canvas c){

    String tag="My Activity";
    Paint paint = new Paint();
    paint.setColor(Color.BLUE);

      c.drawCircle(100,100,100,paint);

}

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

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

}

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




}

I have a secondCircle class that is the exact same as above with the name changed and the color of the circle being Red.

Here is my firstThread class:

public class firstThread extends Thread {

private SurfaceHolder _surfaceHolder;
private firstClass _firstClass;
private boolean _run = false;

public firstThread (SurfaceHolder surfaceHolder, firstClass first){
    _surfaceHolder = surfaceHolder;
    _firstClass= first;

}


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

@Override
public void run(){

    while(_run){
        Canvas c=null;
        try{
            c = _surfaceHolder.lockCanvas(null);
            synchronized(_surfaceHolder){
                    _firstThread.onDraw(c);
            }


        } finally {
        }
            if (c!=null){
                _surfaceHolder.unlockCanvasAndPost(c);
            }
        }
    }

}

I have a secondThread class that is the same as above with a different name and that calls secondCircle’s onDraw().

When i run this program it only shows the blue circle and not the red circle. Why is this?

Answer 1

when you add the views, add them with layout parameters. Its possible the 1st view is filling the parent, leaving no space for the second view.

you could do something like

LinearLayout.LayoutParams p = new LinearLayout.LayoutParams(
                LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT);
    layout.addView(first,p);
    layout.addView(second,p);