public double getAngle() {
        return this.angle;
    }
    
    /**
     * Sets the angle for the anchor point and sends a 
     * {@link DialLayerChangeEvent} to all registered listeners.
     * 
     * @param angle  the angle (in degrees).
     * 
     * @see #getAngle()
     */
    public void setAngle(double angle) {
        this.angle = angle;
        notifyListeners(new DialLayerChangeEvent(this));
    }
    
    /**
     * Returns the radius.
     * 
     * @return The radius.
     * 
     * @see #setRadius(double)
     */
    public double getRadius() {
        return this.radius;