public boolean dropthing(Widget w, Coord c, Object thing) {
		if (w instanceof DropTarget) {
			if (((DropTarget) w).dropthing(c, thing))
				return (true);
		}
		for (Widget wdg = w.lchild; wdg != null; wdg = wdg.prev) {
			Coord cc = w.xlate(wdg.c, true);
			if (c.isect(cc, wdg.sz)) {
				if (dropthing(wdg, c.add(cc.inv()), thing))
					return (true);
			}
		}
		return (false);
	}