public boolean mouseup(Coord c, int button) {
		for (Widget wdg = lchild; wdg != null; wdg = wdg.prev) {
			if (!wdg.visible)
				continue;
			Coord cc = xlate(wdg.c, true);
			if (c.isect(cc, (wdg.hsz == null) ? wdg.sz : wdg.hsz)) {
				if (wdg.mouseup(c.add(cc.inv()), button)) {
					return (true);
				}
			}
		}
		return (false);
	}