Navigator pattern

The following UML sequence diagram shows selected interactions for the basic variant of the Navigator pattern:

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Enhanced Navigator pattern

The following UML class diagram shows an enhanced variant of the Navigator pattern, where the navigators make use of navigation phases, allowing for a unified "admit" operation on the navigables side and a unified "access" operation on the navigators side, the navigators use routing to omit a certain navigation phase, the client can pass navigation strategies to the navigators, and the navigators maintain logbooks to provide a total control and information over the navigation:

(click on the image)