Context-sensitive help UA plug-ins handle the mapping of help contexts to
           context-specific help content and related online documentation topics.
        
        
        For projects that use the DTP help-helper, context-sensitive help plug-ins
           contribute:
            
                - Eclipse context XML files, which supply the context-specific help content for
                    each help context, and point to other help topic contributions related to the
                    help context
- Java properties files, which define the property key-value pairs that map
                    abstract helpKey constants to concrete help context IDs and context-specific
                    help search expressions
Tip: The helpKey properties files are usually contributed in pairs, one each
           for help context IDs and help search expressions.
        
        The following diagram shows how a dedicated context-sensitive help plug-in
           interacts with the DTP help-helper and the Eclipse help system at runtime, to
           provide dynamic context-sensitive help for a UI plug-in.
        
        
        During workbench startup:
            
                - The DTP help-helper registers helpKey properties file contributions, declared
                    by context-sensitive help plug-ins
- The Eclipse help system registers:
                    
 
                        - IContext content contributions, declared by context-sensitive help plug-ins
- Online help (TOC and topics) contributions, declared by documentation plug-ins
 
After the workbench is initialized, the GUI is presented, with workbench parts
           and controls contributed by UI plug-ins. Context-sensitive help requests are
           usually handled by a UI plug-in (or its delegated help event listener), for the
           workbench parts and UI controls that it contributes.
        
        When the user requests context-sensitive help (for example, by pressing F1, or clicking
           a help icon), the following sequence occurs:
            
                - The UI plug-in requests a concrete help context ID from the DTP help-helper,
                    by passing an abstract helpKey.
- The DTP help-helper looks up the help context ID by its associated helpKey,
                    in the helpKey properties file that was registered for the UI plug-in.
- The DTP help-helper returns the help context ID to the UI plug-in.
- The UI plug-in sets the concrete help context ID on its associated workbench
                    part or UI control, and then passes that help context ID to the Eclipse help
                    system to request the display of context-sensitive help.
- The Eclipse help system looks up the context-specific content and related
                    topics by help context ID, retrieves them from the context XML file that was
                    registered for the UI plug-in, and then displays them in the Help view.
- Upon user request (by clicking a related topic link), the Eclipse help system
                    retrieves the help topic content contributed by a documentation plug-in and
                    displays it in the Help view.