This method is a pure virtual member function (the application must implement this function in classes derived from ECLPSListener). This method is called whenever the presentation space is updated and this object is registered to receive update events. The ECLPSEvent object passed as a parameter contains information about the event including the region of the screen that was modified. See ECLPSEvent Class for details.

Multiple PS updates may be aggregated into a single event causing only a single call to this method. The changed region contained in the ECLPSEvent object will encompass the sum of all the modifications.

Events may be restricted to only a particular type of PS update by supplying the appropriate parameters on the ECLPS::RegisterPSEvent() method. For example the application may choose to be notified only for updates from the host and not for local keystrokes.