Model of EMan usage

The programming model of EMan is similar to that of many GUI toolkits. The main program initializes EMan and then registers interest in various types of events. The main program ends by calling a non-returning function of EMan that waits for events and dispatches them as and when they occur. In short, the model includes steps that:

• Initialize the Event Manager,
  
• Register with EMan for all events of interest, and
  
• Hand over control to EMan to loop forever and to dispatch events.

The Event Manager is a SOM object and is an instance of the SOMEEMan class. Since any application requires only one instance of this object, the SOMEEMan class is an instance of the SOMMSingleInstance class. Creation and initialization of the Event Manager is accomplished by a function call to SOMEEmanNew.

Currently, EMan supports the four kinds of events described in the following topic. An application can register or unregister for events in a callback routine (explained below) even after control has been turned over to EMan.