This interface is intended to be implemented by advanced beans that may run either with or without a GUI (graphical user interface) present. The methods it defines allow a bean to specify whether it requires a GUI and allows the environment to notify the bean whether a GUI is available.
If a bean absolutely requires a GUI, it should return true from needsGui(). If a bean is running without a GUI, it should return true from avoidingGui(). If no GUI is available, the bean may be notified through a call to dontUseGui(), and if a GUI is available, the bean may be notified through a call to okToUseGui().
public abstract interface Visibility { // Public Instance Methods public abstract boolean avoidingGui(); public abstract void dontUseGui(); public abstract boolean needsGui(); public abstract void okToUseGui(); }