Adding a keyboard Listener to the movie allows it to be controlled via the Keyboard (once that component has the focus). The key events are received by the KeyController.
The movie is added to the Compositor using the MoviePresenter and a one to one relationship between the key controller and the movie is established in the construction of the controller
Once the controller is added to the Compositor its interest in key events will be available (through the Compositor calling the addedTo method on the Controller). It gets this addedTo / removedFrom messages from the Compositor because it implements the ListenerController and the SimpleSpace super class of the Compositor knows how to deal with controllers of this ilk.
A QTSession.open will perform a gestalt check to ensure that QuickTime is present and is initialized. This is a required call before any QuickTime Java classes can be used.
When the user closes the window the program will quit, first calling QTSession.close to terminate QuickTime. It is necessary for programs to call QTSession.close if they have previously called QTSession.open in order to shut down QuickTime properly.