def size_hint_updated(self):
        # Only the ancestors of a widget care about its size hint and
        # will have added those constraints to a layout, so this method
        # attempts to replace the size hint constraints for the widget
        # starting with its parent.
        parent = self.parent()
        if isinstance(parent, WxConstraintsWidget):
            old_cns = self.size_hint_cns
            del self.size_hint_cns
            new_cns = self.size_hint_cns
            parent.replace_constraints(old_cns, new_cns)
        self.update_geometry()
Notify the layout system that the size hint has changed.
dataset/ETHPy150Open ContinuumIO/ashiba/enaml/enaml/wx/wx_constraints_widget.py/WxConstraintsWidget.size_hint_updated