Using TCollection with an already-defined class

Question

(Note: This is somewhat related to my last question).

I am new to using TCollection in Delphi, and am still wrapping my head around the various ways to handle one-to-many class/property-item relationships. Exploring TCollection and TCollectionItem, I ran into a couple questions:

1) Is it possible to use TCollection or TOwnedCollection for a TForm property? (Haven't tried it yet, but am wondering in advance if its built-in Object Inspector capacities will cause problems).

2) If one ever wants to use some already-defined-elsewhere class, which can't directly descend from TCollectionItem, with TCollection (i.e. kind of "as" a "TCollectionItem"), can that be accomplished? If so, is that something one would accomplish via interfaces?... or what would be the best approach?

Answer 1

1. For the object inspector, it does not matter on what component the properties are defined. Since a TForm descends from TComponent, it is possible.

2. The easiest way is to write a wrapper class (lets call it W) around your already-defined-elsewhere class (lets call it A). Each instance of X owns and encapsulates A.

--jeroen