- Types of GControls:
  - Entries/Selectors
      Text entry boxes, choice boxes and date selectors.
    Valuators
      Numeric valuators for entering numbers and times.
      Can set min/max values and increments.
    Popups
      Various alert and file entry popups.
      Less frequently used since the Swing-based `POPUP` command was added.
    Dialogs
      Popup dialog boxes.
    Displays
      Various display widgets.
    Labels
      Labels are used to divide large sets of controls into logical sections.
      Labels have a roll-up/roll-down feature that allows the user to hide/show a group of controls.
    Lines
      Lines are horizontal lines drawn to separate portions of the control panel.