如何在触摸时增加进度条

Question

我已经实现了一个代码，可以在触摸时显示背面图像。触摸手指移动后方图像视图显示区域和前方图像视图变得不可见。我只想要手上的磨砂按摩我的代码在这里可以有人建议我怎么做

public class StartActivity extends Activity {

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(new TouchView(this));
    }

    public TouchView(Context context) {
        super(context);

        bgr = BitmapFactory.decodeResource(getResources(), R.drawable.bgr);
        overlayDefault = BitmapFactory.decodeResource(getResources(),
                R.drawable.over);
        overlay = BitmapFactory.decodeResource(getResources(),
                R.drawable.over).copy(Config.ARGB_8888, true);
        c2 = new Canvas(overlay);

        pTouch = new Paint(Paint.ANTI_ALIAS_FLAG);
        pTouch.setXfermode(new PorterDuffXfermode(Mode.SRC_OUT));
        pTouch.setColor(Color.TRANSPARENT);
        pTouch.setMaskFilter(new BlurMaskFilter(15, Blur.NORMAL));

    }

    @Override
    public boolean onTouchEvent(MotionEvent ev) {
        switch (ev.getAction()) {
            case MotionEvent.ACTION_DOWN: {
                X = (int) ev.getX();
                Y = (int) ev.getY();
                invalidate();
                break;
            }

            case MotionEvent.ACTION_MOVE: {
                X = (int) ev.getX();
                Y = (int) ev.getY();
                invalidate();
                break;
            }

            case MotionEvent.ACTION_UP:
                break;
        }
        return true;
    }

    @Override
    public void onDraw(Canvas canvas) {
        super.onDraw(canvas);

        // draw background
        canvas.drawBitmap(bgr, 0, 0, null);
        // copy the default overlay into temporary overlay and punch a hole
        // in it
        c2.drawBitmap(overlayDefault, 0, 0, null); // exclude this line to
        // show all as you draw
        c2.drawCircle(X, Y, 80, pTouch);
        // draw the overlay over the background
        canvas.drawBitmap(overlay, 0, 0, null);
    }
}