(Screen Saver with Shapes) Modify your solution to Exercise 13.20 such that it uses random- number generation to choose different shapes to display. Use methods of class Graphics.   (Screen Saver...

(Screen Saver with Shapes)

Modify your solution to Exercise 13.20 such that it uses random- number generation to choose different shapes to display. Use methods of class Graphics.

(Screen Saver Using the Java 2D API)

Modify your solution to Exercise 13.21 to use classes

and drawing capabilities of the Java 2D API. Draw shapes like rectangles and ellipses, with randomly generated gradients. Use class GradientPaint to generate the gradient.