There is a duality of forms (::com::sun::star::form::component::DataForm)
and form controllers. In a document view, for every loaded form there is a form controller which is
responsible for exactly the controls which's models are direct children of the form.
In some sense, a form controller is the view representation of a form, like a form control is the
view representation of a form control model.
This is also reflected in this interface: If you call
XTabController::getModel on a form controller, the form which
the controller is responsible for will be returned.
As always in the model-view-paradigm, there is no way from a model to its controller, mostly, because for
one given form, there is one controller for every view of the document.
A controller is called active if one of the controls it is responsible for has the focus,
else inactive. To be notified whenever this activation state of a given controller changes, you can
add listeners.