A DirectFrame is a basic DirectGUI component that acts as the base
class for various other components, and can also serve as a basic
container to hold other DirectGUI components.
A DirectFrame can have:
* A background texture (pass in path to image, or Texture Card)
* A midground geometry item (pass in geometry)
* A foreground text Node (pass in text string or OnscreenText)
Each of these has 1 or more states. The same object can be used for
all states or each state can have a different text/geom/image (for
radio button and check button indicators, for example).
See the :ref:`directframe` page in the programming manual for a more in-depth
explanation and an example of how to use this class.