Re: How to enter a floating-point number ?

[Russell Shaw <rjshaw netspace net au>]

Gan3sh wrote:
> Le ven 28/05/2004 à 12:38, Paul Pogonyshev a écrit :
>
> > Gan3sh wrote:
> >
> > > The main reason is because some users consider that being able to enter
> > > a letter in "number field" is a bug.
> > > Secondly, there is some overcost in terms of development to display a
> > > message in case of wrong entry.
> > > That's why I was looking a widget that was doing this filter directly.
> >
> > Maybe you should try GtkSpinButton.
>
> Finally, that's what I use, even if the arrows are not relevant in my
> case.

This is a parser problem. Every time a key is pressed, the callback
advances thru your implementation of a floating-point number parser.
When an invalid character is pressed, your callback can simply refuse
to accept the character, make a beep, and display an error message in
the status line. The parser is not hard (only 100 lines of code as
a switch-statement state machine).