ACE/examples/Web_Crawler/URL_Visitor_Factory.h

   1 /* -*- C++ -*- */
   2
   3 //=============================================================================
   4 /**
   5  *  @file    URL_Visitor_Factory.h
   6  *
   7  *  @author Douglas C. Schmidt <d.schmidt@vanderbilt.edu>
   8  */
   9 //=============================================================================
  10
  11
  12 #ifndef _URL_VISITOR_FACTORY_H
  13 #define _URL_VISITOR_FACTORY_H
  14
  15 #include "URL_Visitor.h"
  16 #include "Command_Processor.h"
  17
  18 #if !defined (ACE_LACKS_PRAGMA_ONCE)
  19 #pragma once
  20 #endif /* ACE_LACKS_PRAGMA_ONCE */
  21
  22 /**
  23  * @class URL_Visitor_Factory
  24  *
  25  * @brief Abstract base class that creates URL visitors.
  26  *
  27  * Subclasses define each of the Factory Methods to
  28  * make the right objects, which all "vary" together.
  29  */
  30 class URL_Visitor_Factory
  31 {
  32 public:
  33   /// Destructor.
  34   virtual ~URL_Visitor_Factory ();
  35
  36   /// Factory Method that makes the appropriate type of <URL_Visitor>.
  37   virtual URL_Visitor *make_visitor () = 0;
  38
  39   /// Factory Method that makes the appropriate type of
  40   /// <Command_Processor>.
  41   virtual Command_Processor *make_command_processor () = 0;
  42 };
  43
  44 /**
  45  * @class URL_Validation_Visitor_Factory
  46  *
  47  * @brief Create a URL visitor that validates URL links.
  48  */
  49 class URL_Validation_Visitor_Factory : public URL_Visitor_Factory
  50 {
  51 public:
  52   /// Factory Method that makes a <URL_Validation_Visitor>.
  53   virtual URL_Visitor *make_visitor ();
  54
  55   /// Factory Method that makes a <FIFO_Command_Processor>.
  56   virtual Command_Processor *make_command_processor ();
  57 };
  58
  59 /**
  60  * @class URL_Download_Visitor_Factory
  61  *
  62  * @brief Create a URL visitor that downloads URL links.
  63  */
  64 class URL_Download_Visitor_Factory : public URL_Visitor_Factory
  65 {
  66 public:
  67   /// Factory Method that makes a <URL_Download_Visitor>.
  68   virtual URL_Visitor *make_visitor ();
  69
  70   /// Factory Method that makes a <FIFO_Command_Processor>.
  71   virtual Command_Processor *make_command_processor ();
  72 };
  73
  74 #endif /* _URL_VISITOR_FACTORY_H */