Re: Cast from gchar* to int?

[Martyn Russell <ginxd btopenworld com>]

William L. Thomson Jr. wrote:

> Martyn,
>
> On Tue, 2002-09-24 at 15:13, Martyn Russell wrote:
>  
>
> > It looks to me like you are using the wrong control.  Perhaps you want a 
> > spin button?  This would mean you could guarantee an integer and not a 
> > string with other character (not 0-9) AND you can get an int using a gtk 
> > function call:
> >
> >    
>
> I had thought about it, but prefer the look of the regular text field. I
> have buttons that will handle the incrementing up or down, as well as
> extracting the relevant data from a database and filling in all
> appropriate fields
>  
>
>  
>
> > there is also a function to get it as a float.  Remember if using this 
> > control to call _gtk_spin_button_set_numeric_ to make sure it ONLY 
> > accepts numeric values.
> >    
>
> I like that the spin_button can be set to only accept numeric input. I
> have not found a similar function call for the regular entry fields.
>
> Now with that said, from playing with the spin_button, is there a way to
> not specify a maximum size? The max size will be determined by seeing if
> the table in the database has that many rows. I could set it at run
> time, but it would be another query. One that I would like to avoid if
> possible.
>  
I dont think so, the max is what ever you specify and it is a double so 
you could just make it the maximum possible for a double.?!

> I really would like to stick with the standard gtk_entry widget, and not
> use the spin_button if I can. It should be possible, no?
>  
If you're not worried about actually entering anything into the textbox 
(i.e just using the buttons to increment and decrement) you could always 
just use a gtk_adjustment which isnt visible to the end user and you 
could control it yourself and make your own simple version of the 
spinbutton.  ?

> I am not really worried about non numeric input, because only
> intelligent people will be using this app internally. We know to only
> put numeric input in numeric fields.
>
> I just really would like to know how to convert a char* to an int, and
> why the atoi functions and others will not do this for me. Not to
> mention why they output 0.
>
> If I test with a regular numeric string and convert to an int/long/etc
> using the atoi/atol/etc functions it works. If I swap out my hard coded
> numeric string with the input from the gtk_entry field I get 0.
>
> Really strange and a little frustrating.
>
> Thanks for your input though, I may still have to use the spin_button,
> so thanks for the suggestion.
>
>
>