[Gambas-user] Friend functionality

[Leon Davis]

Thank you very much for your help

Regards
Leon

On Sat, Apr 29, 2017 at 8:05 AM, Tobias Boege <taboege at ...626...> wrote:

> On Sat, 29 Apr 2017, Leon Davis wrote:
> > Gambas v3.9.2 using GTK+3
> >
> > In Microsoft VB there is a "Friend" designation that allows classes in
> the
> > same project to access each others members while protecting  those
> members
> > access from the dot notation. Example: a programmer cannot access a
> friend
> > member by typing "MyClass.ClassMember". Is that functionality available
> in
> > Gambas?
>
> It's not. I think the usual replacement pattern for this in Gambas is to
> declare a pair of functions:
>
>   Public Sub _SetClassMember(Value As Type)
>   Public Function _GetClassMember() As Type
>
> The leading underscore makes the function names hidden in the IDE, but you
> can still access them despite being hidden:
>
>   MyClass._SetClassMember(x)
>   Print MyClass._GetClassMember()
>
> Of course, this offers no real protection. Anyone can use these functions
> from anywhere. You just have to keep the existence of these functions a
> secret between MyClass and its "friends". For example, did you know that
> gb.gui.base's GridView class lets you raise its Select event at will if
> you call GridView._RaiseSelect()?
>
> Gambas has Public and Private for visibility, Read and the absence of Read
> for access and Static for storage. I hope I remember correctly that Benoit
> stated that he doesn't want the Gambas OO mechanisms to become as
> convoluted
> as C++'s. This probably includes the modifiers friend, protected, virtual,
> final and what have you from other languages, as well as multiple
> inheritance,
> polymorphism (sadly) and operator overloading (which is actually available
> to some extent for native components).
>
> Regards,
> Tobi
>
> --
> "There's an old saying: Don't change anything... ever!" -- Mr. Monk
>
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