Scrollable Group with a List using TraitsUI

Question

So I have a problem with my traitsUI code. What I want to have is a List that is shown using CheckListEditor() and is in a confined space so it could be scrollable. I need to have this List in a Group because this would be only a small part of the whole GUI. Yet if I set Group property "scrollable" to "True" that does nothing. Any ideas? Here is minimal working example:

from traits.api import HasTraits, List
from traitsui.api import View, ListEditor, Group, Item, CheckListEditor, Group


class Foo(HasTraits):
    my_list = List()
    full_list = List()

    def _full_list_default(self):
        return [str(n) for n in range(10)]

    traits_view = View(Group(Item('my_list',
                                  style='custom',
                                  editor=CheckListEditor(name = 'full_list')),
                             scrollable = True,
                             orientation = 'vertical'),
                       height=100)

if __name__ == '__main__':
    f = Foo()
    f.configure_traits()

Answer 1

It's the View that should be made scrollable:

from traits.api import HasTraits, List
from traitsui.api import (
    View, ListEditor, Group, Item, CheckListEditor, Group
)

class Foo(HasTraits):
    my_list = List()
    full_list = List()

    def _full_list_default(self):
        return [str(n) for n in range(10)]

    traits_view = View(Group(Item('my_list',
                                style='custom',
                                editor=CheckListEditor(name='full_list')),
                            orientation='vertical'),
                    scrollable=True,
                    height=100)

if __name__ == '__main__':
    f = Foo()
    f.configure_traits()

I get this:

If you want to embed multiple scrollable views you can do it with Instances and InstanceEditors:

    from traits.api import HasTraits, List, Instance
from traitsui.api import (
    View, ListEditor, Group,InstanceEditor, Item, CheckListEditor, Group,
    VGroup
)

class Foo(HasTraits):
    my_list = List()
    full_list = List()

    def _full_list_default(self):
        return [str(n) for n in range(10)]

    traits_view = View(Group(Item('my_list',
                                style='custom',
                                editor=CheckListEditor(name='full_list')),
                            orientation='vertical'),
                    scrollable=True,
                    height=100)

class FooContainingView(HasTraits):
    foo_1 = Instance(Foo)
    foo_2 = Instance(Foo)

    traits_view = View(
        VGroup(
            Item('foo_1',
                editor=InstanceEditor(),
                style='custom',
                show_label=False,
            ),
            Item('foo_2',
                editor=InstanceEditor(),
                style='custom',
                show_label=False,
            ),
        ),
        resizable=True,
    )


if __name__ == '__main__':
    f = Foo()
    fcv = FooContainingView(foo_1=Foo(), foo_2=Foo())
    fcv.configure_traits()

...with this result: