🚀 go-pugleaf

Dear expert,

Would you please, tell me if there is some wellknown desing strategy for
implementiing multi-document application. I have tried and obtained the
follwing problems.
1. How to use menus? The main frame has it's own menu with common items such
"New","Open", "Exit", "About the program" and so on. When a document is
opened the this menu must be extended by document-specific items such as
"Edit" menu items. But it is impossible to merge menus in Swing as I used to
do in Delphi. So the possible solutions are to construct the exdended
menubar in the document frame (or panel) and set it as JMenuBar for the
mainframe at the runtime or to create already extended menubar in the main
frame which includes menu items for all possible actions for all documents
(documens obviously could support different sets of actions and I mostly
interested in this situation). The first approach requiers to import common
actions into the document frame which is not flexible. Using the second
approach we have to query each document if it supports an action or not to
organize automatic updates of the actions.
2. The same design problem appears with the toolbars.
3. I wrote a sample test for the first approach, though it is not very
elegant it works but JBuilder does not support features called in Delphi
world as "visual inheritance". I do not know how to incapsulate menu and
toolbar and the mangement code in base classes and use them in descendant
classes via visal designer. Of course any design strategy will be
interesting but the most valuable are those of then which are JBuilder IDE
compatible.
4. By the way, how is JBuilder IDE designed? It is a very good working
example of the multi-document interface implementation.

Best regards,
Alexei Akimov