This use of this and that in showDialog() is a bit confusing now. On top of that, some of the event handlers are bound and others aren't: _handleItemSelect, _handleItemFocus, _handleKeyUp, _handleKeyDown, _handleResultsReady.

Also, just for consistency, I noticed _handleFilter and _handleResultsFormatter aren't wrapped in a wrapper function like the event handlers are. I'd actually prefer if we remove all the wrapper event handler functions (line 927-932) and change the signatures instead. It might be worth renaming _handleFilter and _handleResultsFormatter too since they aren't actually event handlers.

This is probably more refactoring than necessary, but I think at least we should fix the first issue with this/that and bind.