Re: [Sheflug] stupid C question [SOLVED]

[Alastair Donlon <nospam [at] netsoc.ucd.ie>]

There is a third option -

	declare a new int* variable, copy the auto value into it,
	and use that as the argument to pass to callback1() and
	callback2().

A.D.

On Fri, Nov 03, 2000 at 04:52:46PM +0000, José Luis Gómez Dans wrote:
> Dear all,
> 	Ross has been kind enought to enligthen me on my C woes. <all
> sing merrily>Thanks Ross!</allsingmerrily>
> 
> 	Anyway, I included the message below for reference, but what's
> happening is the fact that my_int_var is defined as an auto variable
> inside a function. It then disappears as the function exits. Ross
> suggested to either:
> a) declare it as static
> b) declare it in main and pass it on to the interface function
> 
> 	Again, thanks both Ross and Alistair.
> 	José
> 
> > > *(int *)user_data = 9;  ?
> > 
> > 	Nice'n easy :) Thanks both Ross and Alastair for the answer.
> > Now, more problems on the way... Let's assume that there's 3 functions
> > in here: interface,callback1 and callback2. In interface() I call
> > callback1 and callback2 with my pointer as per my previous message.
> >   gtk_signal_connect (GTK_OBJECT (plot_ampl), "clicked",
> >   		      GTK_SIGNAL_FUNC (callback1),
> >      		      (gpointer)&my_int_var);
> > 
> >   void callback1(GtkEditable *editable, gpointer user_data);
> >   void callback2(GtkEditable *editable, gpointer user_data);
> > 		
> > 	I want to make sure that callback1 updates the value of
> > my_int_var to something else. I then want this updated value to be used
> > by callback2. For a start, the value is defined as 1 in the interface()
> > function. 
> > 
> > 	However, when an event makes the program go to callback1, the
> > value in the pointer is a rosy 0, instead of 1. Any changes that I might
> > make in callback1 are lost (in principle, I don't mind what value gets
> > to callback1).
> 
> -- 
> José L Gómez Dans			PhD student
> 					Radar & Communications Group
> 					Department of Electronic Engineering
> 					University of Sheffield UK
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