For the purpose of integration with JDev we need a possibility to reuse the NB navigator (the way it gets the specific panels from providers), but allow to provide a different visualization of the panels. The navigator defines its own TopComponent (NavigatorTC) which shows the panels and allow to switch between them. We'd need to replace it with a different TopComponent and different UI for presenting the panels.

1) The interface that can be abstracted for this purpose from NavigatorTC could be as follows:

public interface NavigatorDisplayer {
    String PROP_PANEL_SELECTION = "navigatorPanelSelection"; // NOI18N

    void setDisplayName(String name);
    void setPanels (List<NavigatorPanel> panels, NavigatorPanel select);
    List<NavigatorPanel> getPanels();
    void setSelectedPanel(NavigatorPanel panel);
    NavigatorPanel getSelectedPanel();
    void addPropertyChangeListener(PropertyChangeListener l);
    void removePropertyChangeListener(PropertyChangeListener l);
    boolean allowAsyncUpdate();
    TopComponent getTopComponent();
}

These are basically existing methods in NavigatorTC, so almost no changes are needed in navigator itself for the implementation. We just need to make this API available for someone else to implement differently.

2) Besides the presentation abstraction there's also the navigator initialization itself: how it gets started. Currently it does not do anything (is even not created) until there is the UI that shows it (i.e. the NavigatorTC). We should preserve this deferred initialization. This means that there must be some explicit call from the UI to the navigator to initialize it. The navigator itself has no chance to identify the moment when it should start working (collecting data from providers). For that we also need some API method.

3) When the alternative presentation is used then we also need to hide the Navigator's default TopComponent and its action in Window menu.

So can we achieve this? There can be several variants. Would like to prefer something simple not requiring to rewrite the navigator module completely ;). One question is if this should be public API at all when the use case is so specific (nothing that would be needed by anybody within NetBeans), but having non-public APIs between different products is problematic. So let's explore the public API variants.