specific-contents-query.hpp

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/*
  SPECIFIC-CONTENTS-QUERY.hpp  -  pick specific contents from the model, using a filter
 
   Copyright (C)
     2010,            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 MOBJECT_SESSION_SPECIFIC_CONTENTS_QUERY_H
#define MOBJECT_SESSION_SPECIFIC_CONTENTS_QUERY_H
 
 
#include "steam/mobject/session/scope-query.hpp"
#include "steam/mobject/placement.hpp"
#include "common/query/query-resolver.hpp"
 
#include <functional>
 
 
namespace steam {
namespace mobject {
namespace session {
  
  using std::function;
  
  using lumiera::QueryResolver;
  
  
  template<class MO>
  class SpecificContentsQuery
    : public ContentsQuery<MO>
    {
      using ContentFilter = ContentsQuery<MO>::ContentFilter;
      using TypedPlacement = Placement<MO> const&; 
      using SpecialPredicate = function<bool(TypedPlacement)>;
      
      class Filter
        {
          SpecialPredicate predicate_;
          
        public:
          Filter (SpecialPredicate const& pred)
            : predicate_(pred)
            { }
          
          bool
          operator() (PlacementMO const& anyMO)
            {
              if (!anyMO.isCompatible<MO>())
                return false;
              
              TypedPlacement interestingObject = static_cast<TypedPlacement> (anyMO);
              return predicate_(interestingObject);
            }
        };
      
      Filter specialTest_;
      
      ContentFilter
      buildContentFilter()  const
        {
          return specialTest_;
        }
      
      
      
    public:
      SpecificContentsQuery (PlacementMO  const& scope
                            ,SpecialPredicate const& specialPred)
        : ContentsQuery<MO> (scope)
        , specialTest_(specialPred)
        { }
    };
  
  
  
  namespace { // type matching helper
    template<class PRED>
    struct _PickResult;
    
    template<class MO>
    struct _PickResult<function<bool(Placement<MO> const&)> >
      {
        using Type = MO;
        using FilterQuery = SpecificContentsQuery<MO>;
        using Iterator = ScopeQuery<MO>::iterator;
      };
    
    template<class MO>
    struct _PickResult<bool(&)(Placement<MO> const&)>
      {
        using Type        = MO;
        using FilterQuery = SpecificContentsQuery<MO>;
        using Iterator    = ScopeQuery<MO>::iterator;
      };
    
    template<class MO>
    struct _PickResult<bool(*)(Placement<MO> const&)>
      {
        using Type        = MO;
        using FilterQuery = SpecificContentsQuery<MO>;
        using Iterator    = ScopeQuery<MO>::iterator;
      };
  }
  
  
  
  
  template<typename FUNC>
  inline _PickResult<FUNC>::FilterQuery
  pickAllSuitable(PlacementMO const& scope, FUNC predicate)
  {
    using Query = _PickResult<FUNC>::FilterQuery;
    
    return Query(scope, predicate);
  }
  
  template<typename FUNC>
  inline _PickResult<FUNC>::Iterator
  pickAllSuitable(PlacementMO const& scope, FUNC predicate, QueryResolver const& resolver)
  {
    using Query = _PickResult<FUNC>::FilterQuery;
    
    return Query(scope, predicate ).resolveBy(resolver);
  }
  
  
  
}}} // namespace steam::mobject::session
#endif