Code review comment for lp:~frankban/juju-quickstart/env-manage-selection-view

Reviewers: mp+199484_code.launchpad.net,

Message:
Please take a look.

Description:
Environment list/selection view.

This branch implements the environment
selection Urwid view. It is possible to
start it running `make` and then
`./cli-app-demo.py`. This is still not
integrated in quickstart, but the demo
file demonstrates how to show the view
passing the required data structures
already implemented in the
quickstart.models.envs module.

To test the branch, run `make check`.

To QA the new functionality, run the
demo application as described above,
and play with the interface: any UX
suggestion is welcome, and will be part
of a card we already have
("envs management: ux improvements").

Other changes:

The Urwid application is no longer an
ObjectDict (removed from the code).
I decided to use a Python namedtuple
which seemed to me a better choice,
considering that views are not supposed
to modify the app data structure.
This way we have both immutability and
attribute access to the object.

Implemented a TimeoutText wrapper used to
wrap the message notification widget.
This wayt he timer is restarted when a
subsequent message is set and the previous
has not yet been removed.

https://code.launchpad.net/~frankban/juju-quickstart/env-manage-selection-view/+merge/199484

(do not edit description out of merge proposal)

Please review this at https://codereview.appspot.com/43860044/

Affected files (+588, -110 lines):
   A [revision details]
   M cli-app-demo.py
   M quickstart/cli/base.py
   M quickstart/cli/ui.py
   M quickstart/cli/views.py
   M quickstart/tests/cli/test_base.py
   M quickstart/tests/cli/test_ui.py
   M quickstart/tests/cli/test_views.py
   M quickstart/tests/helpers.py
   M quickstart/tests/test_utils.py
   M quickstart/utils.py