IOleObjectImpl Provides the principal methods through which a container communicates with a control. Manages the activation and deactivation of in-place controls.
IOleInPlaceObjectWindowlessImpl Manages the reactivation of in-place controls. Enables a windowless control to receive messages, as well as to participate in drag and drop operations.
IViewObjectExImpl Enables a control to display itself directly and to notify the container of changes in its display. Provides support for flicker-free drawing, non-rectangular and transparent controls, and hit testing.