Tree, RunTree Questions

You need these files: tree.java and runtree.java.

Current program:

1. Is RunTree an applet or void main program?
2. What global variables are in RunTree?
3. What type of data is in the contentpane of the Frame?
4. What does Tree extend?
5. Which class has the run method?
6. Where is the thread created and started?
7. Why does Tree extend JComponent instead of java.lang.Thread?
8. What are good pre and post conditions of the constructors in both classes?

Changes to make:

1. Change the Tree class so that the constructor allows the user to set a foreground and background colour.
2. Change the RunTree class so that it has two textfields and a button that allow the user to enter the colours to change.