Introduction to OOP: Chapter 8: The Solitaire Game
Class Applet has very structured sequence of operations:
init - to initialize applet
mouseDown and keyPressed to respond to user events
paint to repaint the screen
- Start and stop to begin and halt the applet (not used in this program).
Note also the use of the polymorphic variable allPiles,
which can hold any type of card pile.
Intro OOP, Chapter 8, Slide 22