command-def.hpp

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/*
  COMMAND-DEF.hpp  -  defining and binding a Steam-Layer command

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

  **Lumiera** 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. See the file COPYING for further details.

*/


#ifndef CONTROL_COMMAND_DEF_H
#define CONTROL_COMMAND_DEF_H

#include "lib/error.hpp"
#include "lib/nocopy.hpp"
#include "include/logging.h"
#include "lib/symbol.hpp"
#include "steam/control/command.hpp"
#include "steam/control/command-impl.hpp"                // note: at command definition site we need to know the full type
#include "steam/control/command-registry.hpp"
#include "steam/control/command-signature.hpp"
#include "steam/control/command-mutation.hpp"
#include "steam/control/argument-tuple-accept.hpp"
#include "lib/meta/function.hpp"
#include "lib/meta/typelist.hpp"
#include "lib/meta/typelist-manip.hpp"
#include "lib/meta/tuple-helper.hpp"
#include "lib/util.hpp"

#include <memory>
#include <functional>




namespace steam {
namespace control {
  
  using std::shared_ptr;
  using std::function;
  using std::bind;
  using std::placeholders::_1;
  using std::tuple_size;
  using lib::Symbol;
  
  using lib::meta::_Fun;
  using lib::meta::NullType;
  using lib::meta::Types;
  using lib::meta::TySeq;
  using lib::meta::Tuple;
  
  
  
  
  namespace stage { 
    
    using ImplInstance = shared_ptr<CommandImpl>;
    using Activation   = function<Command&(ImplInstance &&)>;
    
    
    
    
    template<typename SIG>
    struct CompletedDefinition
      : AcceptArgumentBindingRet< Command&, SIG               // Return type and Argument Signature of the \c bind(..) function
                                , CompletedDefinition<SIG>   //  target type (this class) providing the implementation \c bindArg(Tuple<..>) 
                                >
      {
        Command& prototype_;
        
        using CmdArgs = typename _Fun<SIG>::Args;
        
        CompletedDefinition (Command& definedCommand)
          : prototype_(definedCommand)
          {
            REQUIRE (prototype_);
            maybeArm_if_zero_parameters();
            TRACE (command_dbg, "Completed definition of %s.", cStr(prototype_));
          }
        
        
        typedef HandlingPattern::ID PattID;
        
        CompletedDefinition
        setHandlingPattern (PattID newID)
          {
            prototype_.setHandlingPattern(newID);
            return *this;
          }
        
        
        Command&
        bindArg (Tuple<CmdArgs> const& params)
          {
            return prototype_.bindArg(params);
          }
        
        
        operator Command ()
          {
            return prototype_;
          }
        
      private:
        void
        maybeArm_if_zero_parameters()
          {
            if (0 == tuple_size<Tuple<CmdArgs>>::value )
              prototype_.bindArg<> (std::tuple<>());
          }
      };
    
    
    
    
    
    template<typename SIG, typename MEM>
    struct UndoDefinition
      {
        typedef CommandSignature<SIG,MEM> CmdType;
        typedef typename CmdType::OperateSig CommandOperationSig;
        typedef typename CmdType::UndoOp_Sig UndoOperationSig;
        typedef typename CmdType::CaptureSig UndoCaptureSig;
        typedef typename CmdType::CmdArgs    CmdArgs;
        
        typedef function<CommandOperationSig> OperFunc;
        typedef function<UndoOperationSig>    UndoFunc;
        typedef function<UndoCaptureSig>      CaptFunc;
        
        Activation activatePrototype_;
        OperFunc operFunctor_;
        CaptFunc captFunctor_;
        UndoFunc undoFunctor_;
        
        
        UndoDefinition (Activation const& whenComplete, 
                        OperFunc const& commandOperation,
                        CaptFunc const& undoCapOperation)
          : activatePrototype_(whenComplete)
          , operFunctor_(commandOperation)
          , captFunctor_(undoCapOperation)
          , undoFunctor_()
          { }
        
        
        CompletedDefinition<SIG>
        undoOperation (UndoOperationSig how_to_Undo)
          {
            undoFunctor_ = UndoFunc (how_to_Undo);
            REQUIRE (operFunctor_);
            REQUIRE (undoFunctor_);
            REQUIRE (captFunctor_);
            
            CommandRegistry& registry = CommandRegistry::instance();
            ImplInstance completedDef = registry.newCommandImpl(operFunctor_
                                                               ,captFunctor_
                                                               ,undoFunctor_);
            return CompletedDefinition<SIG> {activatePrototype_(move (completedDef))};
          }
      };
    
    
    
    
    template<typename U_SIG>
    struct BuildUndoDefType
      {
        using Type = UndoDefinition<typename U_SIG::OperateSig, typename U_SIG::Memento>;
      };
    
    
    
    
    
    
    template<typename SIG>
    struct BasicDefinition
      {
        Activation callback_;
        function<SIG> operation_;
        
        BasicDefinition(Activation const& whenComplete, function<SIG> const& operation)
          : callback_(whenComplete)
          , operation_(operation)
          { }
        
        
        template<typename FUN2>
        auto
        captureUndo (FUN2 how_to_capture_UndoState)
          {
            using Sig2                   = typename _Fun<FUN2>::Sig;
            using UndoCapSig             = typename UndoSignature<Sig2>::CaptureSig;
            using SpecificUndoDefinition = typename BuildUndoDefType<UndoSignature<Sig2>>::Type;
            
            function<UndoCapSig> captureOperation (how_to_capture_UndoState);
            return SpecificUndoDefinition (callback_, operation_, captureOperation);
          }
      };
    
  } // (END) namespace stage (definition process)
  
  
  class CommandDef
    : util::NonCopyable
    {
      Symbol id_;
      Command prototype_;
      
      using PImpl      = stage::ImplInstance;
      using Activation = stage::Activation;
      
    public:
      CommandDef (Symbol cmdID)
        : id_(cmdID)
        , prototype_(Command::fetchDef(cmdID))
        {
          TRACE (command_dbg, "starting CommandDef('%s')...", cmdID.c() );
        }
      
     ~CommandDef();
      
      
      
      template<typename FUN>
      auto
      operation (FUN operation_to_define)
        {
          using Sig = typename _Fun<FUN>::Sig;
          
          function<Sig> opera1 (operation_to_define);
          Activation callback_when_defined = bind (&CommandDef::activate, this, _1);
          
          return stage::BasicDefinition<Sig>(callback_when_defined, opera1);
        }
      
      
      explicit operator bool()  const { return isValid(); }
      
      bool isValid()  const;
      
      
    private:
      Command& activate (PImpl && completedDef)
        {
          prototype_.activate (move (completedDef), id_);
          ENSURE (prototype_);
          return prototype_;
        }
    };
  
  
  
  
  
}} // namespace steam::control
#endif