prior to 2.4, gtk+ offered two widgets for the task of selecting one item from a list of options. gtkoptionmenu presents the list of options as a menu while gtkcombo presents them in a windows-style list popup. the only difference between the two is that a gtkcombo allows to manually edit the selected value, while the gtkoptionmenu does not. in gtk+ 2.4, a unified api for list selection was introduced, with gtkcombobox for the non-editable case and gtkcomboboxentry for the editable case. the selection of the display style — menu or list — is no longer done at the api level, but has been made themeable via the style property gtkcombobox::appearance. here is an example of a simple, but typical use of gtkoptionmenu:
gtkwidget *option_menu, *menu, *menu_item;
option_menu = gtk_option_menu_new ();
menu = gtk_menu_new ();
menu_item = gtk_menu_item_new_with_label ("first item");
gtk_menu_shell_append (gtk_menu_shell (menu), menu_item);
gtk_widget_show (menu_item);
menu_item = gtk_menu_item_new_with_label ("second item");
gtk_menu_shell_append (gtk_menu_shell (menu), menu_item);
gtk_widget_show (menu_item);
menu_item = gtk_menu_item_new_with_label ("third item");
gtk_menu_shell_append (gtk_menu_shell (menu), menu_item);
gtk_widget_show (menu_item);
gtk_option_menu_set_menu (gtk_option_menu (option_menu), menu);
in order to react to the user's selection, connect to the "changed" signal on the option menu and use gtk_option_menu_get_history() to retrieve the index of the selected item. and here is how it would be done with a gtkcombobox:
gtkwidget *combo_box;
combo_box = gtk_combo_box_new_text ();
gtk_combo_box_append_text (gtk_combo_box (combo_box), "first item");
gtk_combo_box_append_text (gtk_combo_box (combo_box), "second item");
gtk_combo_box_append_text (gtk_combo_box (combo_box), "third item");
in order to react to the user's selection, connect to the "changed" signal on the combo box and use gtk_combo_box_get_active() to retrieve the index of the selected item. a slightly more complex example involving images:
gtkwidget *option_menu, *menu, *menu_item;
option_menu = gtk_option_menu_new ();
menu = gtk_menu_new ();
menu_item = gtk_image_menu_item_new_with_label ("first item");
gtk_image_menu_item_set_image (gtk_image_new_from_pixbuf (pixbuf1));
gtk_menu_shell_append (gtk_menu_shell (menu), menu_item);
gtk_widget_show (menu_item);
menu_item = gtk_image_menu_item_new_with_label ("second item");
gtk_image_menu_item_set_image (gtk_image_new_from_pixbuf (pixbuf2));
gtk_menu_shell_append (gtk_menu_shell (menu), menu_item);
gtk_widget_show (menu_item);
menu_item = gtk_image_menu_item_new_with_label ("third item");
gtk_image_menu_item_set_image (gtk_image_new_from_pixbuf (pixbuf3));
gtk_menu_shell_append (gtk_menu_shell (menu), menu_item);
gtk_widget_show (menu_item);
gtk_option_menu_set_menu (gtk_option_menu (option_menu), menu);
can be done using a gtkcombobox as follows:
gtkliststore *store;
gtktreeiter iter;
gtkcellrenderer *renderer;
gtkwidget *combo_box;
store = gtk_list_store_new (2, gdk_type_pixbuf, g_type_string);
gtk_list_store_append (store, &iter);
gtk_list_store_set (store, &iter, 0, pixbuf1, 1, "first item", -1);
gtk_list_store_append (store, &iter);
gtk_list_store_set (store, &iter, 0, pixbuf2, 1, "second item", -1);
gtk_list_store_append (store, &iter);
gtk_list_store_set (store, &iter, 0, pixbuf3, 1, "third item", -1);
combo_box = gtk_combo_box_new_with_model (gtk_tree_model (store));
renderer = gtk_cell_renderer_pixbuf_new ();
gtk_cell_layout_pack_start (gtk_cell_layout (combo_box), renderer, false);
gtk_cell_layout_set_attributes (gtk_cell_layout (combo_box), renderer,
"pixbuf", 0,
null);
renderer = gtk_cell_renderer_text_new ();
gtk_cell_layout_pack_start (gtk_cell_layout (combo_box), renderer, true);
gtk_cell_layout_set_attributes (gtk_cell_layout (combo_box), renderer,
"text", 1,
null);
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