Aqui está um exemplo de indicador de aplicativo em C. Esta é uma versão "somente indicador" (sem janela) do exemplo fornecido em Wiki do Ubuntu :
#include <libappindicator/app-indicator.h>
static void activate_action (GtkAction *action);
static GtkActionEntry entries[] = {
{"New", "document-new", "_New", "<control>N",
"Create a new file", G_CALLBACK(activate_action)},
{"Open", "document-open", "_Open", "<control>O",
"Open a file", G_CALLBACK(activate_action)},
{"Save", "document-save", "_Save", "<control>S",
"Save file", G_CALLBACK(activate_action)},
{"Quit", "application-exit", "_Quit", "<control>Q",
"Exit the application", G_CALLBACK(gtk_main_quit)},
};
static guint n_entries = G_N_ELEMENTS(entries);
static const gchar *ui_info =
"<ui>"
" <popup name='IndicatorPopup'>"
" <menuitem action='New' />"
" <menuitem action='Open' />"
" <menuitem action='Save' />"
" <menuitem action='Quit' />"
" </popup>"
"</ui>";
static void activate_action(GtkAction *action)
{
const gchar *name = gtk_action_get_name (action);
GtkWidget *dialog;
dialog = gtk_message_dialog_new(NULL,
GTK_DIALOG_DESTROY_WITH_PARENT,
GTK_MESSAGE_INFO,
GTK_BUTTONS_CLOSE,
"You activated action: \"%s\"",
name);
g_signal_connect(dialog, "response",
G_CALLBACK(gtk_widget_destroy), NULL);
gtk_widget_show(dialog);
}
int main(int argc, char **argv)
{
GtkWidget* indicator_menu;
GtkActionGroup* action_group;
GtkUIManager* uim;
AppIndicator* indicator;
GError* error = NULL;
gtk_init(&argc, &argv);
/* Menus */
action_group = gtk_action_group_new("AppActions");
gtk_action_group_add_actions(action_group, entries, n_entries,
NULL);
uim = gtk_ui_manager_new();
gtk_ui_manager_insert_action_group(uim, action_group, 0);
if (!gtk_ui_manager_add_ui_from_string(uim, ui_info, -1, &error)) {
g_message("Failed to build menus: %s\n", error->message);
g_error_free(error);
error = NULL;
}
/* Indicator */
indicator = app_indicator_new("example-simple-client",
"go-jump",
APP_INDICATOR_CATEGORY_APPLICATION_STATUS);
indicator_menu = gtk_ui_manager_get_widget(uim, "/ui/IndicatorPopup");
app_indicator_set_status(indicator, APP_INDICATOR_STATUS_ACTIVE);
app_indicator_set_attention_icon(indicator, "indicator-messages-new");
app_indicator_set_menu(indicator, GTK_MENU(indicator_menu));
gtk_main();
return 0;
}