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Two Widget Subclasses

Listing 5 illustrates the PathWidget subclass derived from the Widget class.

Listing 5 PathWidget Subclass

class PathWidget : public Widget
  explicit PathWidget(ConnectionDirector*);
  virtual ~PathWidget(void);

  void CreateInitialPath(char*);
  void getNewPath(void);
  void ChangePath(char*);
  char* pathDetails;

We’re now moving into the application domain described in Figure 1! The PathWidget class stores its configuration data in the private data member pathDetails. This configuration data takes the form of a character string describing the path taken by an LSP in Figure 1.

Three member functions allow for manipulation of the configuration data:

  • CreateInitialPath() is called at construction time to provide an initial value for pathDetails.
  • getNewPath() is used to retrieve a modified version of pathDetails.
  • ChangePath() is used to change the value of pathDetails.

Listing 6 illustrates the QosWidget subclass.

Listing 6 QosWidget Subclass

class QosWidget : public Widget
  explicit QosWidget(ConnectionDirector*);
  virtual ~QosWidget(void);

  void CreateInitialQoS(char*);
  void getNewQoS(void);
  void ChangeQoSDetails(char*);
  char* QoSDetails;

The QosWidget subclass is very similar to the PathWidget subclass. In fact, they’re so similar that there’s a case for trying to move some of their content into the base class. I’ll leave this as an exercise for the reader! An example of this is the _director data member in Listing 4, which is used by the subclasses.

You’ve seen the interface files; now let’s look at some of the implementation code.

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