Attribute.hpp

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/***************************************************************************
  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

 ***************************************************************************
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 *   version 2 of the License.                                             *
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#ifndef ORO_CORELIB_ATTRIBUTE_HPP
#define ORO_CORELIB_ATTRIBUTE_HPP

#include "internal/DataSource.hpp"
#include "internal/DataSources.hpp"
#include "base/AttributeBase.hpp"

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

        Attribute()
        {
        }

        explicit Attribute(const std::string& name)
            : base::AttributeBase(name),
              data( new internal::ValueDataSource<T>( T() ) )
        {}

        Attribute(const std::string& name, T t)
            : base::AttributeBase(name),
              data( new internal::ValueDataSource<T>( t ) )
        {
        }

        template<class Owner>
        Attribute(const std::string& name, T t, Owner o)
            : base::AttributeBase(name),
              data( new internal::ValueDataSource<T>( t ) )
        {
            o->addAttribute(this);
        }

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

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

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

            if (!ab) {
                data = 0;
                mname.clear();
                return *this;
            }
            typename internal::AssignableDataSource<T>::shared_ptr a
                = boost::dynamic_pointer_cast<internal::AssignableDataSource<T> >( ab->getDataSource() );
            if (a) {
                data = a;
                mname = ab->getName();
            } else {
                data = 0;
            }
            return *this;
        }

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

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

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

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

        typename internal::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 base::DataSourceBase*, base::DataSourceBase*>& replacements, bool instantiate )
        {
            if ( instantiate ) {
                // by taking a clone(), the DS has a chance to instantiate itself.
                // A clone() of an internal::UnboundDataSource returns the bound type.
                internal::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 base::AttributeBase
    {
    public:
        typename internal::DataSource<T>::shared_ptr data;

        Constant()
        {
        }

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

        template<class Owner>
        Constant(const std::string& name, T t, Owner owner)
            : base::AttributeBase(name),
              data( new internal::ConstantDataSource<T>( t ) )
        {
            owner->addAttribute( this );
        }

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

        Constant( base::AttributeBase* ab )
            : base::AttributeBase( ab ? ab->getName() : ""),
              data( ab ? internal::DataSource<T>::narrow( ab->getDataSource().get() ) : 0 )
        {
        }

        Constant<T>& operator=(base::AttributeBase* ab)
        {
            if ( ab == this)
                return *this;
            if (!ab) {
                data = 0;
                mname.clear();
                return *this;
            }
            typename internal::DataSource<T>::shared_ptr a
                = boost::dynamic_pointer_cast<internal::DataSource<T> >( ab->getDataSource() );
            if (a) {
                data = a;
                mname = ab->getName();
            } else {
                data = 0;
            }
            return *this;
        }

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

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

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

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

    class RTT_API Alias
        : public base::AttributeBase
    {
        base::DataSourceBase::shared_ptr data;
    public:
        Alias(const std::string& name, base::DataSourceBase::shared_ptr d );

        template<class Owner>
        Alias(const std::string& name, base::DataSourceBase::shared_ptr d, Owner owner)
            : base::AttributeBase(name),
              data( d )
        {
            owner->addAttribute( this );
        }

        base::DataSourceBase::shared_ptr getDataSource() const;

        Alias* clone() const;

        Alias* copy( std::map<const base::DataSourceBase*, base::DataSourceBase*>& replacements, bool );
    };
}
#endif