The design tool's universe begins in Ctc.java. Main() resides there, as does the code for starting the initialization. However, Ctc.java quickly gives way to DispPanel.java, for it defines the presence and layout of the widgets on the menu bar. The other classes define Singletons and Factories, tied to items from the menu bar.
Subordinate packages define things applied to the display contents and various pop up dialogs.