Attribute.hpp

/***************************************************************************
  tag: Peter Soetens  Tue Dec 21 22:43:08 CET 2004  Attribute.hpp

                        Attribute.hpp -  description
                           -------------------
    begin                : Tue December 21 2004
    copyright            : (C) 2004 Peter Soetens
    email                : peter.soetens@mech.kuleuven.ac.be

 ***************************************************************************
 *   This library 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;                 *
 *   version 2 of the License.                                             *
 *                                                                         *
 *   As a special exception, you may use this file as part of a free       *
 *   software library without restriction.  Specifically, if other files   *
 *   instantiate templates or use macros or inline functions from this     *
 *   file, or you compile this file and link it with other files to        *
 *   produce an executable, this file does not by itself cause the         *
 *   resulting executable to be covered by the GNU General Public          *
 *   License.  This exception does not however invalidate any other        *
 *   reasons why the executable file might be covered by the GNU General   *
 *   Public License.                                                       *
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 *   This library is distributed in the hope that it will be useful,       *
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 *   Lesser General Public License for more details.                       *
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 *   Foundation, Inc., 59 Temple Place,                                    *
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 ***************************************************************************/


#ifndef ORO_CORELIB_ATTRIBUTE_HPP
#define ORO_CORELIB_ATTRIBUTE_HPP

#include "DataSource.hpp"
#include "DataSources.hpp"
#include "AttributeBase.hpp"
#include "BuildType.hpp"

namespace RTT
{
    template<typename T>
    class Attribute
        : public AttributeBase
    {
        typename AssignableDataSource<T>::shared_ptr data;
    public:

        Attribute()
        {
        }

        Attribute(const std::string& name)
            : AttributeBase(name),
              data( detail::BuildType<T>::Value( T() ) )
        {}

        explicit Attribute(const std::string& name, T t)
            : AttributeBase(name),
              data( detail::BuildType<T>::Value( t ) )
        {
        }

        Attribute( const std::string& name, AssignableDataSource<T>* d)
            : AttributeBase(name),
              data( d )
        {
        }

        Attribute( const Attribute<T>& a)
            : AttributeBase( a.mname ),
              data( a.data->clone() )
        {
        }

        Attribute<T>& operator=( const Attribute<T>& a)
        {
            if ( this == &a )
                return *this;
            mname = a.mname;
            data = a.data->clone();
            return *this;
        }

        Attribute( AttributeBase* ab)
            : AttributeBase( ab ? ab->getName() : "" ),
              data( ab ? AssignableDataSource<T>::narrow( ab->getDataSource().get() ) : 0 )
        {
        }

        Attribute<T>& operator=(AttributeBase* ab)
        {
            if ( ab == this )
                return *this;

            if (!ab) {
                data = 0;
                return *this;
            }
            mname = ab->getName();
            Attribute<T>* a = dynamic_cast<Attribute<T>*>(ab);
            if (a)
                data = a->getAssignableDataSource();
            return *this;
        }

        T get() const
        {
            return data->get();
        }

        void set( T t )
        {
            data->set(t);
        }

        typename AssignableDataSource<T>::reference_t set() {
            return data->set();
        }

        DataSourceBase::shared_ptr getDataSource() const
        {
            return data;
        }

        typename AssignableDataSource<T>::shared_ptr getAssignableDataSource() const
        {
            return data;
        }

        Attribute<T>* clone() const
        {
            return new Attribute<T>( mname, data.get() );
        }

        Attribute<T>* copy( std::map<const DataSourceBase*, DataSourceBase*>& replacements, bool instantiate )
        {
            if ( instantiate ) {
                // by taking a clone(), the DS has a chance to instantiate itself.
                // A clone() of an UnboundDataSource returns the bound type.
                AssignableDataSource<T>* instds = data->clone();
                replacements[ data.get() ] = instds;
                return new Attribute<T>( mname, instds );
            }
            else {
                return new Attribute<T>( mname, data->copy( replacements ) );
            }
        }
    };

    template<typename T>
    class Constant
        : public AttributeBase
    {
    public:
        typename DataSource<T>::shared_ptr data;

        Constant(const std::string& name, T t)
            : AttributeBase(name),
              data( new ConstantDataSource<T>( t ) )
        {
        }

        Constant(const std::string& name, DataSource<T>* d )
            : AttributeBase(name),
              data( d )
        {
        }

        Constant( AttributeBase* ab )
            : AttributeBase( ab ? ab->getName() : "")
        {
            if ( !ab )
                return;
            Constant<T>* c = dynamic_cast<Constant<T>*>(ab);
            if (c)
                data = c->getDataSource();
        }

        Constant<T>& operator=(AttributeBase* ab)
        {
            if (!ab) {
                data = 0;
                return *this;
            }
            mname = ab->getName();
            Constant<T>* c = dynamic_cast<Constant<T>*>(ab);
            if (c)
                data = c->getDataSource();
        }

        T get() const
        {
            return data->get();
        }

        DataSourceBase::shared_ptr getDataSource() const
        {
            return data;
        }

        Constant<T>* clone() const
        {
            return new Constant<T>( mname, data.get() );
        }

        Constant<T>* copy( std::map<const DataSourceBase*, DataSourceBase*>& replacements, bool instantiate )
        {
            // 'symbolic' copy, ConstantDataSource returns 'this' on copy...
            Constant<T>* ret = new Constant<T>( mname, data.get() );
            return ret;
        }
    };

    template<typename T>
    class Alias
        : public AttributeBase
    {
        typename DataSource<T>::shared_ptr data;
    public:
        Alias(const std::string& name, typename DataSource<T>::shared_ptr d )
            : AttributeBase(name),
              data( d )
        {
        }

        DataSourceBase::shared_ptr getDataSource() const
        {
            return data;
        }

        Alias<T>* clone() const
        {
            return new Alias<T>( mname, data.get() );
        }
        Alias<T>* copy( std::map<const DataSourceBase*, DataSourceBase*>& replacements, bool )
        {
            // instantiate does not apply.
            return new Alias<T>( mname, data->copy( replacements ) );
        }
    };
}
#endif