-gtk_combo_select_child_callback( GtkList *WXUNUSED(list), GtkWidget *WXUNUSED(widget), wxComboBox *combo )
-{
-    if (g_isIdle) wxapp_install_idle_handler();
-
-    if (!combo->m_hasVMT) return;
-
-    if (g_blockEventsOnDrag) return;
-
-    int curSelection = combo->GetSelection();
-
-    if (combo->m_prevSelection == curSelection) return;
-
-    GtkWidget *list = GTK_COMBO(combo->m_widget)->list;
-    gtk_list_unselect_item( GTK_LIST(list), combo->m_prevSelection );
-    
-    combo->m_prevSelection = curSelection;
-
-    // Quickly set the value of the combo box
-    // as GTK+ does that only AFTER the event
-    // is sent.
-    gtk_signal_disconnect_by_func( GTK_OBJECT(GTK_COMBO(combo->GetHandle())->entry),
-      GTK_SIGNAL_FUNC(gtk_text_changed_callback), (gpointer)combo );
-    combo->SetValue( combo->GetStringSelection() );
-    gtk_signal_connect( GTK_OBJECT(GTK_COMBO(combo->GetHandle())->entry), "changed",
-      GTK_SIGNAL_FUNC(gtk_text_changed_callback), (gpointer)combo );
-
-    wxCommandEvent event( wxEVT_COMMAND_COMBOBOX_SELECTED, combo->GetId() );
-    event.SetInt( curSelection );
-    event.SetString( combo->GetStringSelection() );
+gtkcombobox_popupshown_callback(GObject *WXUNUSED(gobject),
+                                GParamSpec *WXUNUSED(param_spec),
+                                wxComboBox *combo)
+{
+    gboolean isShown;
+    g_object_get( combo->m_widget, "popup-shown", &isShown, NULL );
+    wxCommandEvent event( isShown ? wxEVT_COMMAND_COMBOBOX_DROPDOWN
+                                  : wxEVT_COMMAND_COMBOBOX_CLOSEUP,
+                          combo->GetId() );