Re: Re: Re: Calling a module with a gpointer to data.

[Harring Figueiredo <harringf yahoo com>]

  Jim, 

 I solved the problem.

 First off, I am getting a lot of Gkt Errors due to the pixmap. - I am just
taking that you did not send the pixmaps to me, but you know how to solve that
prblem.

  Now, to the important stuff.

 You have:
G_MODULE_EXPORT void
sayHello( gpointer data)
{
   printf(" %s" data);  /* -- and here is where things "blow up." */
}

 -- You are passing the pointer correctly -- however, you are assigning this
function as if it was a GtkSignalFunc -- ( you are casting it; therefore, the C
compiler does not tell you anything about the mistake., it just assumes you are
the boss.)

   To be a  GtkSignalFunc , the function signature must be : 
   sayHello(GtkWidget* w, gpointer data) --  I made that change and BINGO !! it
worked.

   You also have something like:
typedef void* (mod_func) (gpointer data);  /* Return and accept void, so we can
                          pass any data in/out */

This is unecessary -- I removed on the code I am sending to you -- since you
already have GtkSignalFunc (Which is the same thing.) -- In fact, wrong, since
the connect signal takes a GtkSignalFunc type; which is different from the
above decl.


 -- Run the program that I am sending -- You will see that "sayHello" will
work, but "sayGoodbye" will not work-- I left it unchanged since it is the same
change you need to make -- I left it as exercise :P)


   Take care and thanks for sending the code and the explanation.

Harring Figueiredo.



-- Jim Parker <hopeye cfl rr com> wrote:
> Do not know the spot in the code, but I know the steps to reproduce.
>
> If you compile and run ...
>
> Under the file menu, there is a menu choice "load modules" Select this and
> the module is loaded and it creates a new sub menu "plug-ins"  Under this
> new menu they is the another sub-menu "sayHello" (or somethin along those
> lines) and 2 choices.
>
> These choices call fuctions from the module library.  Selecting either of
> the choices calls the correct function, but the data pointer is corrupt (ie
> it prints out garbage characters).
>
> I build the menu with functions in the misc.c file.  The loading and
> unloading of the modules are in plugin.c, and module code is in sayhello.c
> and sayhello.h
>
> Thanks for looking at my code.
>
> cheers,
> Jim Parker
>
> On Wed, 31 Jul 2002, Harring Figueiredo wrote:
> > Date: Wed, 31 Jul 2002 08:00:22 -0700 (PDT)
> > To: hopeye cfl rr com, GTK+ mailing list <gtk-app-devel-list gnome org>
> > From: Harring Figueiredo <harringf yahoo com>
> > Sender: gtk-app-devel-list-admin gnome org
> > Subject: Re: Re: Calling a module with a gpointer to data.
> >
> >
> >  Jim,
> >
> >  I got your code.
> >
> >  Could you walk me or point me to the place where the problem is ?
> >
> >   i.e --  on line 32 of file blah.c I get a core dump or on line 56 of
> > file
> > blah.c I show the widget but it never goes to the screen ?
> >
> >   Thanks.
> >
> > By the way -- I have helped you before on the Plugin part right ? I
> > noticed
> > that you are in Central Fl. -- I am in Orlando. :P)
> >
> >
> > Harring
> >
> > --- Jim Parker <hopeye cfl rr com> wrote:
> > > Ok here is the code.
> > >
> > > I did not understand your comment about the stack versus the heap.
> > >
> > > Thanks for your help
> > >
> > > cheers
> > > Jim Parker
> > >
> > > On Mon, 29 Jul 2002, Harring Figueiredo wrote:
> > > > Date: Mon, 29 Jul 2002 20:56:12 -0700 (PDT)
> > > > To: hopeye cfl rr com, GTK+ mailing list
> > <gtk-app-devel-list gnome org>
> > > > From: Harring Figueiredo <harringf yahoo com>
> > > > Sender: gtk-app-devel-list-admin gnome org
> > > > Subject: Re: Calling a module with a gpointer to data.
> > > >
> > > >
> > > > Could you provide the code ?
> > > >
> > > >  It seems - from the description -that you are passing a "string"
> > greated
> > > > on
> > > > the stack, and not on the heap.
> > > >
> > > > Harring
> > > >
> > > > --- Jim Parker <hopeye cfl rr com> wrote:
> > > > > G'Day !
> > > > >
> > > > > My application uses plug-ins to extend the functionality.  When I
> > load
> > > > a
> > > > > plug-in I build a menu structure in the normal way.  But when I
> > attach
> > > > a
> > > > > callback to the menu.  The data pointer seems to be corrupt.
> > > > >
> > > > > Currently I am just passing a text string.  But when I call the
> > > > function it
> > > > > does not print properly (garbage characters).  It works great for
> > the
> > > > menu
> > > > > items that were created in the main program.
> > > > >
> > > > > Do I need to do something differently ?
> > > > >
> > > > > cheers,
> > > > > Jim Parker
> > > > >
> > > > > _______________________________________________
> > > > > gtk-app-devel-list mailing list
> > > > > gtk-app-devel-list gnome org
> > > > > http://mail.gnome.org/mailman/listinfo/gtk-app-devel-list
> > > >
> > > >
> > > > __________________________________________________
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> >
> > > ATTACHMENT part 2 application/octet-stream name=plugin.tar.gz
> >
> >
> >
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