GTK system tray icon example

It's hard to find an example of system tray icon example. In the past, we should use libegg, but this library is deprecated. The current option, when using GTK, is the Status Icon. GTK implements freedesktop's System Tray specification and works on any desktop environment that is compliant (like KDE or GNOME).

I created a very simple example to help other people to solve this problem more quickly in the future:

#include 

void tray_icon_on_click(GtkStatusIcon *status_icon, 
                        gpointer user_data)
{
        printf("Clicked on tray icon\n");
}

void tray_icon_on_menu(GtkStatusIcon *status_icon, guint button, 
                       guint activate_time, gpointer user_data)
{
        printf("Popup menu\n");
}

static GtkStatusIcon *create_tray_icon() {
        GtkStatusIcon *tray_icon;

        tray_icon = gtk_status_icon_new();
        g_signal_connect(G_OBJECT(tray_icon), "activate", 
                         G_CALLBACK(tray_icon_on_click), NULL);
        g_signal_connect(G_OBJECT(tray_icon), 
                         "popup-menu",
                         G_CALLBACK(tray_icon_on_menu), NULL);
        gtk_status_icon_set_from_icon_name(tray_icon, 
                                           GTK_STOCK_MEDIA_STOP);
        gtk_status_icon_set_tooltip(tray_icon, 
                                    "Example Tray Icon");
        gtk_status_icon_set_visible(tray_icon, TRUE);

        return tray_icon;
}

int main(int argc, char **argv) {
        GtkStatusIcon *tray_icon;

        gtk_init(&argc, &argv);
        tray_icon = create_tray_icon();
        gtk_main();

        return 0;
}

Don't forget to compile with GTK libraries.

There are some other aspects when implementing a tray icon and you want to minimize to tray, such as:

- Hide/Show window to avoid minimizing it to the task bar (yes, use gtk_widget_hide() and gtk_widget_show()) when the user clicks on the system tray icon
- Listen to the "window-state-event" (GObject's signal) to detect when minimizing and, instead of doing that, hide the window (ie, "minimize to the tray").

Finally, in case you experienced something interesting concerning system tray icons, please share with us.