Usage Notes

To be notified of PS updates using this class, the application must perform the following steps:

1. Define a class derived from ECLPSListener.
2. Implement all methods of the ECLPSListener-derived class.
3. Create an instance of the derived class.
4. Register the instance with the ECLPS::RegisterPSEvent() method.

After registration is complete, updates to the presentation space will cause the NotifyEvent() method of the ECLPSListener-derived class to be called. The application can then used the ECLPSEvent object supplied on the method call to determine what caused the PS update and the region of the screen affected.

Note that multiple PS updates which occurred in a short period of time may be aggregated into a single event notification.

An application can choose to provide its own constructor and destructor for the derived class. This can be useful if the application needs to store some instance-specific data in the class and pass that information as a parameter on the constructor.

If an error is detected during event registration, the NotifyError() member function is called with an ECLErr object. Events may or may not continue to be generated after an error. When event generation terminates (due to an error or some other reason) the NotifyStop() member function is called.