Re: How many times can I call gtk_label_set_markup()?

[Igor Korot <ikorot01 gmail com>]

Hi, David,

2011/4/8 David Nečas <yeti physics muni cz>:
> On Fri, Apr 08, 2011 at 01:17:52AM -0700, Igor Korot wrote:
>> I need to change the markup text in the label conditionally in the loop.
>> However, I'm getting this on the second call of gtk_label_set_markup():
>>
>> (mini2440gtk:19672): GLib-GObject-WARNING **: invalid cast from
>> `(null)' to `GObject'
>>
>> (mini2440gtk:19672): GLib-GObject-CRITICAL **: g_object_freeze_notify:
>> assertion `G_IS_OBJECT (object)' failed
>>
>> (mini2440gtk:19672): GLib-GObject-WARNING **: invalid cast from
>> `(null)' to `GObject'
>>
>> (mini2440gtk:19672): GLib-GObject-CRITICAL **: g_object_notify:
>> assertion `G_IS_OBJECT (object)' failed
>>
>> (mini2440gtk:19672): GLib-GObject-WARNING **: invalid cast from
>> `(null)' to `GtkWidget'
>>
>> (mini2440gtk:19672): Gtk-CRITICAL **: gtk_widget_queue_resize:
>> assertion `GTK_IS_WIDGET (widget)' failed
>>
>> (mini2440gtk:19672): GLib-GObject-WARNING **: invalid cast from
>> `(null)' to `GObject'
>>
>> (mini2440gtk:19672): GLib-GObject-CRITICAL **: g_object_thaw_notify:
>> assertion `G_IS_OBJECT (object)' failed
>>
>> I checked and the window and the text are both not NULL.
>>
>> Is it possible to do it this way? Or I just need to dereference something?
>
> gtk_label_set_markup() can be called an arbitrary number of times.
> You do not need to *dereference* anything.  You may need to reference
> the label – if it's been removed from the container it was in.
>
> Otherwise the only conclusion that can be made from this is that you
> code is buggy.
>
> Run it with G_DEBUG=fatal-warnings to obtain a stack trace at the first
> warning and see what exactly gets the NULL pointer instead of an object.

$ ./<program_name> G_DEBUG=fatal-warnings

Right?

Thank you.

>
> Yeti
>
>