The ctf.view package provides two primary classes: FieldView and Console.
FieldView is a java.awt::Canvas that displays the current state of a CTF game. When its refresh() method is called, it queries its GameViewInterface to find out where all of the players currently are, etc.
The FieldViewTester class is a GameViewInterface that will provide valid, though uninteresting, values to a FieldView. You may wish to use it when building your GUI, so that FieldView can draw some default values.
The Console is a PrintStream, like System.out or System.err, that you may use to display output text. You may use as many Console windows as you like, so for instance, you may display all messages received in one window, responses in another and errors in yet another. Like all of ctf-tools, you do not have to use it.