Listing 2. Code snippets from the .cpp implementation file for KeyPadPart

The complete OS/2 implementation for this class is available as part of a Redbook produced by IBM.

SOM_Scope void  SOMLINK KPInitSemanticInterface(
                        KeyPadPart *somSelf,
                        Environment *ev)
{
    ...
     _fSemtIntf      = new ODSemanticInterface();
     // ODSemanticInterface derives directly from
     // ODBaseSemanticInterface,
     // shown in Figure 1. above.  This call instantiates
     // the ODSemanticInterface extension.

     _fSemtIntf->InitSemanticInterface(ev, somSelf,
                                       _fSession);
     // This call initializes the ODSemanticInterface
     // extension.
    ...
}
============================================================
SOM_Scope ODBoolean  SOMLINK HasExtension(
                     KeyPadPart *somSelf,
                     Environment *ev,
                     ODType extensionName)
{
...
    if (!strcmp(extensionName, kODExtSemanticInterface)) {
       // kODExtSemanticInterface is a constant defined
       // in the stdexts.xh header file

       return kODTrue;
    } else {
       // Check to see if the parent supports this extension
       return (KeyPadPart_parent_SimplePart_HasExtension(
               somSelf,
               ev,
               extensionName));
    }
}
============================================================
SOM_Scope ODExtension*  SOMLINK AcquireExtension(
                                KeyPadPart *somSelf,
                                Environment *ev,
                                ODType extensionName)
{
   ...
   if(!strcmp(extensionName, kODExtSemanticInterface)) {
       return _fSemtIntf;
       // return the extension we instantiated when
       // KeyPadPart was initialized
   }
   ,,,
}