super.onCreate(savedInstanceState);

            setContentView(R.layout.main);
            mPanel = (Panel) findViewById(R.id.yourID);
            mPanel.setBackgroundColor(Color.WHITE);
            mPanel.requestFocus();

private void prepareBitmaps() {



int a=255;
int r=255;
 int g=255;
    int b=255;

        if (mBitmap == null) {

                tCanvas = getHolder().lockCanvas();
                mBitmap = Bitmap.createBitmap(350, 350, Bitmap.Config.ARGB_8888);
                mCanvas = new Canvas(mBitmap);
                tmpBitmap = Bitmap.createBitmap(350,350, Bitmap.Config.ARGB_8888);
                tmpCanvas = new Canvas(tmpBitmap);
        //tCanvas.getWidth(), tCanvas.getHeight()
            //   tmpCanvas.drawColor(farba);
              tmpCanvas.drawARGB(a,r,g,b);
                mCanvas.drawARGB(a, r, g, b);
              // mCanvas.drawColor(farba);
                getHolder().unlockCanvasAndPost(tCanvas);
                tCanvas = null;

        }
}