[Gambas-user] Custom Control

[Benoît Minisini]

> Benoît Minisini wrote:
> > In Gambas 3, the /control directory must be put inside the "Project"
> > section.
> 
> Okay, that worked. I was using the control directory automatically
> created when I first created the project. Thanks.
> 
> > Please provide the details of what you have done, and maybe I will tell
> > you.
> 
> I'm referring to code used when programming the component itself.
> 
> For example, in the component code:
> 
> Public Sub _new(lVal1 As Long, lVal2 As Long, Optional lVal3 As Long)
> 
> If I make the component and try to use it in a project, I have to also
> pass the parent container name. So, if I use:
> 
> oVar = New ComponentName(lVal1, lVal2, lVal3, FMain)
> 
> It works fine. But if I try to leave out the *optional* argument:
> 
> oVar = New ComponentName(lVal1, lVal2, FMain)
> 
> I will get "Not enough arguments" from the IDE. If I try:
> 
> oVar = New ComponentName(lVal1, lVal2, , FMain)
> 
> I will get "Unexpected Comma" from the IDE. And, of course, if I pass
> NUll as the optional argument, it's the incorrect data type for the
> argument. I understand why I'm getting the messages I'm getting. I'm
> just asking is there any way to use an *optional* argument to the _new
> sub of a component.
> 
> This isn't something critical. This is just a personal project I chose
> to do as an exercise, to get familiar with Gambas. I always do stuff
> like this whenever I'm learning a new language or (in this case) IDE, etc.
> 

You get a point there: optional arguments cannot really be used in 
constructors, unless you do not use inheritance. Because the rule is that if 
an argument is optional, all following arguments are. Which is a contradiction 
with the way arguments are used.

Maybe I should change the way arguments are consumed by inherited 
constructors. I mean not inverting them, i.e. inverting them on the stack, so 
that you write New MyControl(FMain, lVal1, lVal2...). But this will uses some 
CPU.

I must think about that...

-- 
Benoît Minisini