I've implemented dropdown bar support for my language.  The bar displays the
right entiries, and I've hooked the OnItemChosen() method to move the caret
in the text view to the right place when an item is clicked.

However, after an item is chosen in the dropdown bar, the focus remains on
the bar - the bar item is still highlighted. The bar in  VC++ doesn't do
this: focus goes back to the edit window.

So I tried SendExplicitFocus() on the IVsTextView to focus the edit window
again.  However, while this does sort of solve the problem (the cursor
re-appears in the edit window), the dropdown bar remains highlighted and the
edit window doesn't really have focus: moving the mouse wheel doesn't scroll
it, for example.

So what's the right way to re-assign focus after an item on the dropdown bar
is selected?