90 lines
2.3 KiB
C++
90 lines
2.3 KiB
C++
/*****************************************************************************
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*
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* This file is part of Mapnik (c++ mapping toolkit)
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*
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* Copyright (C) 2006 Artem Pavlenko
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*
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* This library is free software; you can redistribute it and/or
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* modify it under the terms of the GNU Lesser General Public
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* License as published by the Free Software Foundation; either
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* version 2.1 of the License, or (at your option) any later version.
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*
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* This library is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* Lesser General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General Public
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* License along with this library; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
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*
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*****************************************************************************/
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//$Id$
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#ifndef FILTER_HPP
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#define FILTER_HPP
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//#include "filter_visitor.hpp"
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#include "feature.hpp"
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namespace mapnik
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{
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template <typename FeatureT> class filter_visitor;
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template <typename FeatureT>
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class MAPNIK_DECL filter
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{
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public:
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virtual bool pass(const FeatureT& feature) const=0;
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virtual filter<FeatureT>* clone() const=0;
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virtual void accept(filter_visitor<FeatureT>& v) = 0;
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virtual std::string to_string() const=0;
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virtual ~filter() {}
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};
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typedef boost::shared_ptr<filter<Feature> > filter_ptr;
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template <typename FeatureT>
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class all_filter : public filter<FeatureT>
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{
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public:
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bool pass (const FeatureT&) const
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{
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return true;
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}
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filter<FeatureT>* clone() const
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{
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return new all_filter<FeatureT>;
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}
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std::string to_string() const
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{
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return "true";
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}
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void accept(filter_visitor<FeatureT>&) {}
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virtual ~all_filter() {}
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};
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template <typename FeatureT>
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class none_filter : public filter<FeatureT>
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{
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public:
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bool pass (const FeatureT&) const
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{
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return false;
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}
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filter<FeatureT>* clone() const
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{
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return new none_filter<FeatureT>;
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}
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std::string to_string() const
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{
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return "false";
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}
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void accept(filter_visitor<FeatureT>&) {}
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virtual ~none_filter() {}
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};
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}
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#endif //FILTER_HPP
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