Game: ball rebound logic

Question

From a Pong game, I've getted the logic to make the ball rebound on the walls of the X-axis. This is the logic that makes this:

Main method:

protected void handleBounces(float px, float py) {
        /*Rebound on X-axis*/
        if(mBall.x <= Ball.RADIUS || mBall.x >= getWidth() - Ball.RADIUS) {
            mBall.bounceWall();
            if(mBall.x == Ball.RADIUS)
                mBall.x++;
            else
                mBall.x--;
        }
}

Ball logic:

public void bounceWall() {
            setAngle(3 * Math.PI - mAngle);
}

public void setAngle(double angle) {
            mAngle = angle % (2 * Math.PI);
            mAngle = boundAngle(mAngle);
            findVector();
}

protected double boundAngle(double angle) {
            return boundAngle(angle, angle >= Math.PI);
}

protected void findVector() {
            vx = (float) (speed * Math.cos(mAngle));
            vy = (float) (speed * Math.sin(mAngle));
}

Now, I need to do the same, but for the Y-axis's top side, this is. I'm making a mod to the pong game, that consists on just one paddle (at the bottom) and the ball must rebound on the other 3 walls.

As said, I make it rebound on the X-axis walls, but I need now make it rebound on the Top side of the screen (Y-axis top side).

I tried several ways, but the ball doesn't rebound. I think that with an implementation like this, it should work, but doesn't work, the ball continues and dissapears at the top:

Main method:

protected void handleTopFastBounce(float px, float py) {
        if(mBall.goingUp() == false) return;

        if(mBall.y <= Ball.RADIUS) {
            mBall.bounceWall();
            playSound(mWallSFX);
            if (mBall.y == Ball.RADIUS) {
                mBall.y++;
            }
        }
}

Ball logic: Same as for the method above, but adding this method:

public boolean goingUp() {
            return mAngle >= Math.PI;
}

Answer 1

Finally I solved my own:

Just have to make this mods:

Main method:

protected void handleTopFastBounce() {
        if(mBall.goingUp() == false) return;

        if(mBall.y <= Ball.RADIUS) {
            mBall.bounceTop();
            mBall.y++;
        }
}

Ball logic: Create a new method modifying the bounceWall() method:

public void bounceTop() {
            setAngle(4 * Math.PI - mAngle);
}