Question

I have a textbox asking for a value. How can I capture this value and pass on this to another function?

int main (int argc, char *argv[]) {
  GtkWidget *window,*table,*label,*entry;
  gtk_init(&argc, &argv);

  //Create the main window
  window = gtk_window_new(GTK_WINDOW_TOPLEVEL);
  initialize_window(window);

   /* Create a 1x2 table */
   table = gtk_table_new (1, 2, TRUE);
   gtk_container_add (GTK_CONTAINER (window), table);

  /* create a new label. */
  label = gtk_label_new ("Enter some text:" );
  //gtk_misc_set_alignment (GTK_MISC (label), 0, 0);
  gtk_table_set_homogeneous(GTK_TABLE (table), TRUE);
  gtk_table_attach_defaults (GTK_TABLE (table), label, 1, 2, 0, 1);

  //create a text box
  //  entry = gtk_entry_new ();
  gtk_entry_set_max_length (GTK_ENTRY (entry),0);
  gtk_table_attach_defaults (GTK_TABLE (table), entry, 0, 1, 0, 1);
  gtk_widget_show_all(window);
}

Now I want to use this value and pass it to some function.

Answer 1

Something like this should work. When the Enter key is pressed, entry_activated will be called:

static void entry_activated(GtkEntry *entry, gpointer user_data)
{
    int i;
    const gchar *entered = gtk_entry_get_text(entry);

    i = atoi(entered); // strtol() would be better, but this will work.

    g_message("Entry: %d", i);
}

int main (int argc, char *argv[]) {
    /* ... stuff ... */

    entry = gtk_entry_new();
    g_signal_connect(G_OBJECT(entry), "activate", G_CALLBACK(entry_activated), NULL);

    /* ... stuff ... */
}