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2.8 Interoperability Layer

 


                                              



 
   Figure 48. Interoperability 

   The interoperability layer was defined from CI Labs to enable the 
   collaboration of OpenDoc components and OLE parts.  The interoperability 
   layer is part of the OpenDoc architecture and was developed by Novell. It 
   will be delivered first as part of the Windows version of OpenDoc, but is 
   planned for OS/2 also.  In September 95, IBM took over the development 
   from Novell.  OpenDoc does not compromise the use of OLE/OCX applications, 
   but can add enhanced functions to them provided by OpenDoc.  OpenDoc can 
   also be used as a powerful tool to create OLE components, providing an 
   interface for developers that is less complex than the OLE APIs. 


 


                                              



 
   Figure 49. OpenDoc  OLE Interoperability 

   Because OpenDoc's object model is supporting inheritance, most of the 
   complexity can be hidden by prefabricated components.  The 
   interoperability between OpenDoc and OLE, as shown in Figure 49, is 
   achieved by the following two wrapper objects: 

   °   An OLEWrapper wraps an OpenDoc part and provides it with an OLE server 
       interface.  OCX support is also added at the moment.  This enables 
       OpenDoc parts to be embedded in OLE-based applications. 
   °   An OLEPart is wraps an OpenDoc container component and provides it 
       with an OLE container interface. This enables OpenDoc container 
       components to embed OLE OCX parts. 

   OLE has a similar mechanism to customize it parts called OLE automation. 
   Interoperability will also be provided between the OSA and OLE automation. 
   That means OpenDoc components can be driven also from environments such as 
   Visual Basic. 

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