use gtk_widget_get_window instead of struct field

diff --git a/src/graph.c b/src/graph.c
index be253b7..2625ce5 100644 (file)
--- a/src/graph.c
+++ b/src/graph.c
@@ -314,7 +314,7 @@ graph_update(struct psensor **sensors,
                }
        }
 
-       cr_pixmap = gdk_cairo_create(w_graph->window);
+       cr_pixmap = gdk_cairo_create(gtk_widget_get_window(w_graph));
 
        if (cr_pixmap) {