Convenience method for setting a component's foreground, background and font properties with values from the defaults. The properties are only set if the current value is either null or a UIResource.

Parameters:

c		component set to the colors and font on
defaultBgName		key for the background
defaultFgName		key for the foreground
defaultFontName		key for the font

Exceptions:

NullPointerException

as described in exceptions

See also:
installColors, UIManager.getColor, UIManager.getFont