Pick one of the following problems to do for your interclass problem. Ideal solutions to all of these include the use of an image. You would paint to the image and then draw that image when the paint method is called. They can all be done without that, but that would make them more functional.
1. Follow the Mouse - Make an applet where a simple geometric shape follows the mouse around.
2. Keyboard Control - Make an applet that has a simple geometric shape that moves around when you press keys. (Remeber that as we saw in class, dealing with key focus. To make the applet listen to key presses you need to have it be a mouse listener and in the mouseClicked method you need to call requestFocus().)
3. Drawing Lines - Make an applet that allows the user to draw lines. To do this it should store a list of lines and the paint method should draw those lines. When the user presses down the mouse button you want to remember that location. When they release you add a new line that goes from the point where the mouse button was pressed to the point where it was released. To store the lines you can either make your own class or you can use the java.awt.geom.Line2D.Double class.