One possible solution would be the following:
Considering that the Region is defined on a
ContentControl, you could ask the Region
for the ActiveViews, which in this case there would be
only one, that is, the only Active View that is being
Therefore, you would not need the
Focus/LostFocus events. The
Region would take care of updating its
ActiveViews list each time you navigate to a different
Tab or View.
Finally, in order to decide whether to show or hide the
GridTools, you should evaluate if the Region's
ActiveView contains a Grid control or not. You
could achieve this by looking at UserControl's Content
I hope this helped you, Regards.