Bug description:

When the UIB datepicker changes modes, the focus is lost. This makes keyboard navigation difficult when mode switching is used.

Link to minimally-working plunker that reproduces the issue:

http://angular-ui.github.io/bootstrap/#!#datepickerPopup

Steps to reproduce the issue:

1. Open the date picker popup.
2. Press Ctrl+Up
3. Datepicker is no longer focused

Version of Angular, UIBS, and Bootstrap

Angular: 1.6.1

UIBS: 2.5.0

Bootstrap: 3.3.7

Probable reason

I'm guessing this is caused by the ng-switch swapping out the datepicker div, meaning that no element has focus.