paddle是一个绘制的长方形球拍，brick是长方形砖块，请写出paddle、bricks；请你按照下列要求写个反应碰撞的程序It would be very useful to write this section of code as a separate method private GObject getCollidingObject() that returns the object involved in the collision, if any, and null otherwise. You could then use it in a declaration like GObject collider = getCollidingObject(); which assigns that value to a variable called collider. – 7 – From here, the only remaining thing you need to do is decide what to do when a collision occurs. There are only two possibilities. First, the object you get back might be the paddle, which you can test by checking if (collider == paddle) . . . If it is the paddle, you need to bounce the ball so that it starts traveling up. If it isn’t the paddle, the only other thing it might be is a brick, since those are the only other objects in the world. Once again, you need to cause a bounce in the vertical direction, but you also need to take the brick away. To do so, all you need to do is remove it from the screen by calling the remove method.

根据要求，我先定义paddle和bricks：

GRect paddle = new GRect(0, 0, PADDLE_WIDTH, PADDLE_HEIGHT);
GRect brick = new GRect(0, 0, BRICK_WIDTH, BRICK_HEIGHT);

然后，我定义了一个私有方法getCollidingObject()，用于检测球拍和砖块是否与球发生碰撞，并返回碰撞的对象：

private GObject getCollidingObject() {
    if (getElementAt(ball.getX(), ball.getY()) != null) {
        return getElementAt(ball.getX(), ball.getY());
    } else if (getElementAt(ball.getX() + BALL_RADIUS * 2, ball.getY()) != null) {
        return getElementAt(ball.getX() + BALL_RADIUS * 2, ball.getY());
    } else if (getElementAt(ball.getX(), ball.getY() + BALL_RADIUS * 2) != null) {
        return getElementAt(ball.getX(), ball.getY() + BALL_RADIUS * 2);
    } else if (getElementAt(ball.getX() + BALL_RADIUS * 2, ball.getY() + BALL_RADIUS * 2) != null) {
        return getElementAt(ball.getX() + BALL_RADIUS * 2, ball.getY() + BALL_RADIUS * 2);
    } else {
        return null;
    }
}

在主程序中，我可以使用上面定义的方法来检测碰撞，并根据碰撞的对象来进行相应的处理：

while (true) {
    moveBall();
    GObject collider = getCollidingObject();
    if (collider == paddle) {
        vy = -vy;
    } else if (collider != null && collider != ball) {
        remove(collider);
        vy = -vy;
        bricksLeft--;
        if (bricksLeft == 0) {
            break;
        }
    }
    pause(DELAY);
}

在上面的程序中，我使用了一个while循环来不断移动球，并检测碰撞。如果碰撞的对象是球拍，就将球的y方向速度取反，使其向上反弹；如果碰撞的对象是砖块，就将该砖块从屏幕上移除，并将球的y方向速度取反，使其向上反弹。同时，我还记录了剩余未被消除的砖块数量，当所有砖块都被消除时，就跳出循环。

需要注意的是，这只是一个简单的碰撞检测和反应的例子，实际的游戏中可能会涉及到更加复杂的碰撞检测和处理逻辑。