I'm looking for some info and/or source on class and property editor for something like TCollection, but with an ability to accept different classes and with a full design-time support. Unfortunately, in design-time, TCollection and it's editor may operate with only one class type (ItemClass property).
Something similar to my target can be found in GLScene unit by Mike Lischke, where one can add different classes in design-time, but the code is a bit buggy and I can not find enough info to remove those bugs, or create my own editor.
Even Delphi's source code (colnedit.pas) refers to some strange TToolbarDesignWindow class which I can not find in Delphi destribution.
I would really appreciate any help with some good advice or source code sample.