understanding callback functions

[Oliver Lamm <oli Athos bordernet de>]

Hi !


I've a little porblem which might be simple.

I have the following scenario:

- one main window with one vbox. In the lower vboxpart is a button
  called mybutton.

My goal:

- A label should be displayed in the upper vboxpart when the button is pressed.

My problem:

- I create the window, vbox, button with no problems. But then I want
  to connect a signal_handler to the clicked-event.

I tried the following:

gtk_signal_connect_object(GTK_OBJECT(mybutton), "clicked",
                          GTK_SIGNAL_FUNC(klickme),
                          GTK_OBJECT(myvbox));

This is my callback-function klickme:

void klickme(GtkButton * mybutton, gpointer data){

    GtkWidget *label;

    label = gtk_label_new("test");
    gtk_box_pack_start(GTK_BOX(data),label)
        
}
        
The programm compiled, but if i press the button I get the following
failure:

Gtk-CRITICAL **: file gtkbox.c line 330(gtk_box_pack_start):
assertion 'GTK_IS_BOX (box)' failed

Can somebody post perhaps the correct code do do what I trie here ?

Yours, Oliver


-- 
8<------------------------------------------------------------->8
Oliver Lamm                     Administrator HDZ/IMA RWTH Aachen
lamm hdz-ima rwth-aachen de                 Tel.: +49-241-9666-30