+ /* items will not prevent Item::move() moving
+ * them to a negative x-axis coordinate, which
+ * is legal, but we don't want that here.
+ */
+
+ ArdourCanvas::Item *item = get_canvas_group ();
+
+ if (item->position().x + x_delta < 0) {
+ x_delta = -item->position().x; /* move it to zero */
+ }
+
+ item->move (ArdourCanvas::Duple (x_delta, y_delta));