[Gambas-user] How to draw on a ScrollArea from with in a class that inherits ScrollArea?

[Tobias Boege]

On Mon, 12 Oct 2015, Moviga Technologies wrote:
> Your example works.... I realise now that the problem was that I called
> Test() from within the class, but you are calling it from the outside. I
> guess the ScrollArea was not properly instantiated. Is there any way to
> test if the class has been properly created from within the .Class file?
> (It really doesn't matter any more now with my current project, but
> perhaps for the future.) 

If you run code (which is not in a Static procedure) from the class, it must
be executed in the context of an object of that class. Therefore: whenever
you execute code, the object *is* ready[*].

>From what you're saying, I can only conclude that you didn't understand how
the Draw event works. You can only paint on a ScrollArea during its Draw
event. Naturally this event is caught not by the ScrollArea itself but by
another object (like the Form the ScrollArea lives on or a UserControl which
embeds the ScrollArea). You could, nevertheless, catch your own events using
an Observer, but your current solution with the UserControl is much better.

Regards,
Tobi

[*] The object constructor, _new(), plays a special role here. The object
    cannot raise events before its constructor finishes.

-- 
"There's an old saying: Don't change anything... ever!" -- Mr. Monk