Re: Can't locate object method "new_text" via package "Gtk2::ComboBox"

[muppet <scott asofyet org>]

On Jan 24, 2006, at 1:30 AM, Eisenknapp, Josef wrote:

> I wrote a program useing a Gtk2::ComboBox. On my computer at home  
> everything works fine, but on the redhat computer in the office  
> keep getting the message:
>
> "Can't locate object method "new_text" via package  
> "Gtk2::ComboBox" (perhaps you forgot to load  
> "Gtk2::ComboBox"?)........"

GtkComboBox was added to gtk+ in version 2.4.0, and support for it  
was added to Gtk2 in 1.040.  However, even if Gtk2 is newer than  
1.040, Gtk2::ComboBox will be missing if you compile against gtk+  
older than 2.4.

RHEL3 and Fedora Core 1 have gtk+ 2.2.x.
RHEL4 and Fedora Core 2 have gtk+ 2.4.x.

If the object isn't there in gtk+, you simply can't use it.


> I have a similar problem with the "->set_keep_above (TRUE)" method  
> for a window.

Same story on versions.


Supporting old systems can be a drag, because you can't use the  
latest and greatest objects from gtk+.  However, i have several  
archaic systems to maintain, myself, so i've pulled a few of these  
tricks.

It's a bit more work, but it's possible to add fallback code and  
determine at runtime which code to execute.  For example, collect all  
the code to deal with comboboxes in one function or class, and  
maintain two paths:

   sub create_combo {
       my %options = @_;
       if ($Gtk2::VERSION >= 1.040 && Gtk2->CHECK_VERSION(2, 4, 0)) {
           # Gtk2::ComboBox is available!  Use it!
           ...
       } else {
           # We're on an older setup that doesn't have ComboBox.
           # Use Gtk2::OptionMenu or Gtk2::Combo instead.
           ...
       }
   }

See L<Glib::version> and L<Gtk2::version> for more information.

Or, just take the easy route and use only the widgets that are  
available in gtk+ 2.0 for maximum compatibility.  Yes, that does  
sometimes hurt.


--
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  -- Slogan on a giant paper airplane hung in Lobby 7 at MIT.
     http://hacks.mit.edu/