Re: [gtk-list] Combo signal problem

[Allan Black <allan genia scotnet co uk>]

> I'm using a combo-list where I call a function every time the selection 
> is changed. I use the "selection-changed" signal to do this, and this 
> works mostly fine, except that when I select an entry the signal-handler 
> is called 4 times.

Every time you drag over one of the popdown strings, the entry gets updated
and you get sent a signal.

> Since my signal handler connects to a MySQL database to fetch information 
> this is wasting resources.

I had this problem too. In my case, there was visual feedback, so the screen
kept changing while the mouse was being dragged up & down the menu.

> Is there a practical way to avoid the 3 extra calls, or do I have to put 
> in a  check to see whether the signal was just done with the same data?

[I actually found this solution by looking at the AbiWord source.]

Connect to the "hide" signal on the combo's popup menu. When the menu is
hidden, go and see what value the user finally settled for.

        gtk_signal_connect(GTK_OBJECT(GTK_COMBO(w)->popwin), "hide",
			GTK_SIGNAL_FUNC(mycallback), w);

static void mycallback(GtkWidget *w, GtkCombo combo)
{
	gchar *value;

	value = gtk_entry_get_text(GTK_ENTRY(combo->entry));

	[...]
}

Allan