[Gambas-user] define a startup class?

Benoit Minisini gambas at ...2...
Tue May 20 09:10:16 CEST 2003


Le Lundi 19 Mai 2003 15:23, Rob a écrit :
> On Monday 19 May 2003 04:48, Benoit Minisini wrote:
> > When you have a form named Form1 in VB, and you type Form1.Show, what
> > happens in the background ? Exactly what you must do by hand in Gambas:
> > the form is instanciated, and the instance is given the same name as the
> > form.
>
> Indeed, and that's why I hope to automate and hide the process in Gambas.
> There's no need for the user to see it if it's the same in every project.
>
> > 1) The newbie is confused, because class and instance of this class have
> > the same name. So the newbie don't really understand what he does
> > exactly.
>
> True, and it's kinda hard to reuse forms in VB.  Nonetheless, there are a
> lot of VB programmers who are going to be interested in Gambas and I see no
> reason to hinder them with good programming style ;)  The truth is, even in
> your examples to date you don't have any examples of form reuse, and I
> expect most VB programmers are used to the idea that forms only ever get
> loaded once.  So I think that making it optionally easy for the user (since
> this is BASIC after all) is more important than Java-like reuse of
> everything.
>
> > 2) The form is instanciated when you try to use the form class as a form
> > instance. You save two lines of code and one variable at first, but when
>
> Far more importantly, you save a learning curve.  People expect to be able
> to just create a form, hit F5 and have it come up.  That's the beauty of
> VB, the ability to make it do something visible without writing a single
> line of code.  VB's appeal has never been clean design or good programming
> style or any of that stuff, it's been the fact that it's easy to learn and
> use.  And Linux programmers who value "technically correct" solutions are
> already using C/C++/Java, whereas VB programmers currently have nowhere to
> go.
>
> > you want to exit the program, you must be very careful not to make a
> > reference to a closed form, elsewhere this form is recreated, and your
> > program does not exit ! (I had this problem many times in my VB programs)
>
> Having never actually unloaded a form in VB except to force an exit (by
> unloading the main form), I never ran into this problem.
>
> > Maybe I could have the same behavior with forms on Gambas. But I think
> > that the disadventages are greater than the advantages.
>
> We have different goals.  You're looking to make something that's like VB,
> only good.  I'm looking for something that will make VB programmers as
> comfortable under Linux as Openoffice makes Word users.
>
> > Modifying the IDE will not help you... It is a functionnality that must
> > be add to the interpreter: something like auto-instanciating class. But I
> > don't even know if it is technically possible at the moment !
>
> Sure I can.  As far as the "press F5 without having written any code" issue
> goes, I can add something to the properties dialog that says "Make VB style
> project with this startup form:", create a file called "vbproj.class" which
> is hidden from view in the IDE and contains a sub main that instantiates
> and shows the desired form.  vbproj.class becomes the startup class as far
> as Gambas the language is concerned, just as myfilename.vbp is the "startup
> class" of a VB project, but the user never sees or edits it.  That part's
> pretty trivial.
>
> Since you don't seem to have implemented project-wide global variables or
> include files yet, I haven't figured out a way to instantiate all the forms
> in the project at startup yet (which would take care of the "form being
> instantiated the first time you refer to it" problem), nor how to refer to
> those forms outside the startup class if you do, so I may be stuck there
> for now.  It seems to me the easiest way to take care of that without
> bothering non-VB-familiar Gambas users would be to make a compiler
> directive like "USE GLOBALS" or something that extends the scope of public
> variables to the entire project.  But even without any of that, just having
> VB programmers or novice Gambas programmers make a form, run it and have it
> show up
> automatically will be a breakthrough in making Gambas seem easier than it
> is, I think.
>
> I know it's ugly, but so is VB and I'm trying to recreate the VB experience
> using Gambas. ;)  I am utterly uninterested in teaching VB programmers how
> to be better programmers of other languages, I just want them to be able to
> say, "Hey, there's an equivalent tool for Linux that's just as easy."  I
> never tried to teach Word users LyX or LaTeX and I'm not going to try to
> teach VB users about encapsulation and strongly typed variables.  I'm
> hoping to at least get a tool together that recreates their .frm files as
> Gambas forms, even if I can't convert the code automatically.  And I know
> that's not your goal, and so I'll try to avoid stepping on your toes (I
> can't imagine that I'll touch the interpreter, for one thing.)  I mean no
> disrespect by any of this; I just want to make life easier for my users.
>
> I suppose this really belonged on gambas-devel, sorry about that.
>
> Rob

No problem, let's go to gambas-devel !

-- 
Benoit Minisini
mailto:gambas at ...1...




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