CompuServe Messages

Burt, > That is, the instance variable is not global, so what do I refer to when > I want to say "x->addrow()"? What is 'x' and where do I get it from if > it is not a 'gX' global? There are two "x"s. One is the list pane (usually a subclass of CArrayPane), the other is its data. We'll call the pane the AddressesList, and we'll call the data the AddressesArray. AppMaker generates an instance variable for the pane. It's in your window class, so within that class you can call (e.g.) AddressesList->AddRow(…). The data for your list you'll normally define in the Data class. In the initialization method for your list pane subclass you'll call AddressesList->SetArray(AddressesArray). As a matter of good programming practice, you normally don't refer directly to another class's instance variables. You instead call a member function (aka method) in that class that accesses its instance variables (aka data members). So in your data class, you'll have functions for manipulating (adding, removing, etc.) the AddressesArray. The TCL uses the Collaborator mechanism to keep the array and the pane in sync. As you add elements to AddressesArray, the TCL automatically adds rows to AddressesList by BroadcastChange/ProviderChanged. Most of your classes will have an instance variable, itsData, that is a pointer to your data class object. If necessary, you'll pass itsData to other classes so that they can store a copy in their own instance variables. You'll call such things as itsData->AddAddress(anAddress). The functions in the data class will access the AddressesArray to add, remove, etc. entries. Spec