Re: GTK critical assertion : WIDGET_REALIZED_FOR_EVENT

[muppet <scott asofyet org>]

On Jan 3, 2007, at 11:48 PM, Ashwin Ramachandran wrote:

> HI All,
> I am using Perl-Gtk2 and observing this assertion, once in a while,  
> when the application is opened:
>
> ==================================================================
> $ Gtk-CRITICAL **: gtk_widget_event: assertion
> `WIDGET_REALIZED_FOR_EVENT (widget, event)' failed
> at /usr/share/osfr/tools/ddore.pl line 1192.
> Gtk-CRITICAL **: gtk_widget_event: assertion  
> `WIDGET_REALIZED_FOR_EVENT
> (widget, event)' failed at /usr/share/osfr/tools/ddore.pl line 1192.
>
>
>
> The line #1192 the assertion points to is
>     main Gtk2; <-----
>     exit( 0 );
>
> I am not sure why this assertion is happening, since I am not able  
> to debug further[since it points to the event loop].

It points to the Gtk2::main line because that was the location of the  
last perl statement executed before the error.  When these assertion  
messages are emitted, they are run through a log message handler  
which appends the perl file and line number with the Carp utilities.   
What this means is that something you set up in the code prior to  
starting the main loop caused an assertion after the main loop  
started.  This is unfortunately rather commonplace.

The actual assertion message that you're seeing is from inside gtk+.   
It means that a widget is trying to handle an event before that  
widget has been "realized" --- that is, there is no actual gdk window  
for the widget yet, so the widget can't handle the event.  It's most  
likely that you have forgotten to show() some widget somewhere.


> I am using Glade and building my main window using Glade files.

This makes it a little harder to debug, since we can't look at actual  
code to see which widgets aren't being show()n.  Make sure that all  
the widgets you want to be live have their "visible" properties  
active, and that you have called show() on the toplevel window properly.


> Just wanted to check if anyone in this group has encountered any  
> similar problem? Is there any more data that I need to supply for  
> this issue?

If you want to get your hands a little dirty, then you can actually  
run your program in both the perl and c debuggers and find out  
exactly where this assertion is failing; that often helps.