Re: While does it segfaults

["Paolo Costabel" <pcostabel futurecombat net>]

You can't memcpy gtk objects. They contain pointers and stuff.
To duplicate a GtkAdjustment, you need to allocate a new one.
In your case, you don't need a new adjustment object. Change your code as
follows:

void show ( GtkWidget * w )
{
    GtkAdjustment * adj

    adj = gtk_scrolled_window_get_vadjustment ( GTK_SCROLLED_WINDOW
 scrolledwindow1 ) );

    printf ( "Value: %f\n", adj->value );

    gtk_adjustment_set_value(adj,39.0);
}

----------------------------------------------------------------
Paolo Costabel
Sony Imageworks


----- Original Message -----
From: "Fabio Rotondo" <mlists rotondo it>
To: "gtk-devel" <gtk-app-devel-list gnome org>
Sent: Monday, December 17, 2001 8:14 AM
Subject: While does it segfaults


> Hi list,
>
>   could anyone please tell me why this piece of code segfaults?
>
> Do the following:
>
> 1 - Run the app
> 2 - Move the vscrollbar (in the middle)
> 3 - Press the button
> 4 - Try to move the vscrollbar again -> segfault
>
> Thanks,
>
>   Fabio


----------------------------------------------------------------------------
----


> /*
>  * DO NOT EDIT THIS FILE - it is generated by Glade.
>  */
>
> #include <string.h>
> #include <gtk/gtk.h>
>
>
>   GtkWidget *clist1;
>   GtkWidget *scrolledwindow1;
>
> void show ( GtkWidget * w )
> {
> GtkAdjustment * adj;
> GtkAdjustment a;
>
> adj = gtk_scrolled_window_get_vadjustment ( GTK_SCROLLED_WINDOW
 scrolledwindow1 ) );
> memcpy ( &a, adj, sizeof ( GtkAdjustment ) );
>
> printf ( "Value: %f\n", a.value );
>
> a.value = 39.0;
>
>   gtk_scrolled_window_set_vadjustment ( GTK_SCROLLED_WINDOW
 scrolledwindow1 ), &a );
> }
>
> int main ( int argc, char * argv[] )
> {
>   GtkWidget *window1;
>   GtkWidget *vbox1;
>   GtkWidget *label3;
>   GtkWidget *label4;
>   GtkWidget *label5;
>   GtkWidget *button1;
> int t;
> char * a[4];
>
> gtk_init ( &argc, &argv );
>
>   window1 = gtk_window_new (GTK_WINDOW_TOPLEVEL);
>   gtk_object_set_data (GTK_OBJECT (window1), "window1", window1);
>
>   vbox1 = gtk_vbox_new (FALSE, 0);
>   gtk_container_add (GTK_CONTAINER (window1), vbox1);
>
>   scrolledwindow1 = gtk_scrolled_window_new (NULL, NULL);
>   gtk_widget_show (scrolledwindow1);
>   gtk_box_pack_start (GTK_BOX (vbox1), scrolledwindow1, TRUE, TRUE, 0);
>
>   clist1 = gtk_clist_new (3);
>   gtk_container_add (GTK_CONTAINER (scrolledwindow1), clist1);
>   gtk_clist_set_column_width (GTK_CLIST (clist1), 0, 80);
>   gtk_clist_set_column_width (GTK_CLIST (clist1), 1, 80);
>   gtk_clist_set_column_width (GTK_CLIST (clist1), 2, 80);
>   gtk_clist_column_titles_show (GTK_CLIST (clist1));
>
>   label3 = gtk_label_new ("label3");
>   gtk_clist_set_column_widget (GTK_CLIST (clist1), 0, label3);
>
>   label4 = gtk_label_new ("label4");
>   gtk_clist_set_column_widget (GTK_CLIST (clist1), 1, label4);
>
>   label5 = gtk_label_new ("label5");
>   gtk_clist_set_column_widget (GTK_CLIST (clist1), 2, label5);
>
>   button1 = gtk_button_new_with_label ("button1");
>   gtk_box_pack_start (GTK_BOX (vbox1), button1, FALSE, FALSE, 0);
>
> gtk_signal_connect ( GTK_OBJECT ( button1 ), "clicked", show, NULL );
>
> a[0] = "one";
> a[1] = "two";
> a[2] = "three";
>
> for ( t = 0; t < 40; t++)
>   gtk_clist_append ( GTK_CLIST ( clist1 ), a );
>
> gtk_widget_show_all ( window1 );
>
> gtk_main ();
>
> }