handling-patterns.hpp

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/*
  HANDLILNG-PATTERNS.hpp  -  Collection of predefined command handling patterns

  Copyright (C)         Lumiera.org
    2009,               Hermann Vosseler <Ichthyostega@web.de>

  This program is free software; you can redistribute it and/or
  modify it under the terms of the GNU General Public License as
  published by the Free Software Foundation; either version 2 of
  the License, or (at your option) any later version.

  This program is distributed in the hope that it will be useful,
  but WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  GNU General Public License for more details.

  You should have received a copy of the GNU General Public License
  along with this program; if not, write to the Free Software
  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.

*/


#ifndef CONTROL_HANDLING_PATTERNS_DEF_H
#define CONTROL_HANDLING_PATTERNS_DEF_H

#include "lib/error.hpp"
#include "lib/multifact.hpp"
#include "steam/control/handling-pattern.hpp"
#include "steam/control/command-impl.hpp"



namespace steam {
namespace control {

  namespace { // concrete command handling patterns 
    
    
    
    
    class BasicHandlingPattern
      : public HandlingPattern
      {
        bool isValid()  const { return true; }
        
        void
        performExec (CommandImpl& command)  const override
          {
            REQUIRE (command.canExec());
            command.invokeCapture();
            command.invokeOperation();
          }
        
        void
        performUndo (CommandImpl& command)  const override
          {
            REQUIRE (command.canUndo());
            command.invokeUndo();
          }
      };
    
    
    
    class InvokeSyncNoThrow
      : public BasicHandlingPattern
      {
        void
        performExec (CommandImpl& command)  const override
          {
            UNIMPLEMENTED ("actually invoke a command, according to this pattern");
          }
        
        void
        performUndo (CommandImpl& command)  const override
          {
            UNIMPLEMENTED ("actually undo the effect of a command, according to this pattern");
          }
        
        bool
        isValid()  const override
          {
            UNIMPLEMENTED ("is this pattern currently able to handle commands?");
          }
      };
    
    
    
    class InvokeSyncThrow
      : public BasicHandlingPattern
      {
        void
        performExec (CommandImpl& command)  const override
          {
            UNIMPLEMENTED ("actually invoke a command, according to this pattern");
          }
        
        void
        performUndo (CommandImpl& command)  const override
          {
            UNIMPLEMENTED ("actually undo the effect of a command, according to this pattern");
          }
        
        bool
        isValid()  const override
          {
            UNIMPLEMENTED ("is this pattern currently able to handle commands?");
          }
      };
    
    
    
    class InvokeAsync
      : public BasicHandlingPattern
      {
        void
        performExec (CommandImpl& command)  const override
          {
            UNIMPLEMENTED ("actually invoke a command, according to this pattern");
          }
        
        void
        performUndo (CommandImpl& command)  const override
          {
            UNIMPLEMENTED ("actually undo the effect of a command, according to this pattern");
          }
        
        bool
        isValid()  const override
          {
            UNIMPLEMENTED ("is this pattern currently able to handle commands?");
          }
      };
    
    
    
    
    
    
    /* ======== Handling Pattern Table ========== */
    
    typedef lib::factory::MultiFact<HandlingPattern&, HandlingPattern::ID> HandlingPatternFactory;
    
    HandlingPatternFactory patternTable;
    
    HandlingPatternFactory::Singleton<InvokeSyncNoThrow>    holder1 (patternTable, HandlingPattern::SYNC);
    HandlingPatternFactory::Singleton<InvokeSyncThrow>      holder2 (patternTable, HandlingPattern::SYNC_THROW);
    HandlingPatternFactory::Singleton<InvokeAsync>          holder3 (patternTable, HandlingPattern::ASYNC);
    HandlingPatternFactory::Singleton<BasicHandlingPattern> holder4 (patternTable, HandlingPattern::DUMMY);
    
    
    inline HandlingPattern const&
    getPatternInstance (HandlingPattern::ID id)
    {
      REQUIRE (patternTable.contains(id));
      
      return patternTable (id);
    }
    
  
  } // (END) definition of concrete handling patterns
  
  
  
  
  
  
  
}} // namespace steam::control
#endif