Demonstrate issue in reparenting in enaml

enaml_parent_issue.enaml

# -*- coding: utf-8 -*-
from enaml.core.api import Conditional
from enaml.widgets.api import (Window, Container, ObjectCombo, PushButton,
                               ScrollArea, GroupBox, Label)


enamldef Displayable(GroupBox): cont:

    attr sp_children = []

    func refresh():
        for c in sp_children:
            c.set_parent(self)
            c.show()

    initialized ::
        refresh()

    PushButton:
        text = 'Add label'
        clicked ::
            Label(text='Dummy').set_parent(cont)

C2 = Displayable(title='C2')

C1 = Displayable(title='C1', sp_children=[C2])


enamldef Main(Window):

    attr displayables = {'C1': C1, 'C2': C2}

    initialized::
        C1.set_parent(scroll)
        C1.show()

    Container:
        ObjectCombo:
            items = sorted(displayables)
            selected ::
#                if 'oldvalue' in change:
#                    displayables[change['oldvalue']].set_parent(None)
                view = displayables[change['value']]
#                if view.proxy_is_active:
#                    view.proxy.layout_container = None
                view.set_parent(scroll)
                view.refresh()
                view.show()

        ScrollArea: scroll:
            pass