gistfile1.h

static void
set_event_box_background (GtkWidget *event_box)
{
    GError *error = NULL;
    const gchar *file_path = g_strjoin ("/", PKGDATADIR, "images", "slider_bg.png", NULL);
    GdkPixbuf *pixbuf = gdk_pixbuf_new_from_file (file_path, &error);
    GdkPixmap *pixmap = NULL;
    GdkPixmap *mask = NULL;

    gdk_pixbuf_render_pixmap_and_mask (pixbuf, &pixmap, &mask, 255);
    GtkStyle *orig_style = gtk_widget_get_style (event_box);
    GtkStyle *style = gtk_style_copy (orig_style);
    style->bg_pixmap[GTK_STATE_NORMAL] = pixmap;
    gtk_widget_set_style (event_box, style);
}