mapnik/include/mapnik/attribute_collector.hpp
2007-10-08 18:10:31 +00:00

102 lines
3 KiB
C++

/*****************************************************************************
*
* This file is part of Mapnik (c++ mapping toolkit)
*
* Copyright (C) 2006 Artem Pavlenko
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*
*****************************************************************************/
//$Id$
#ifndef ATTRIBUTE_COLLECTOR_HPP
#define ATTRIBUTE_COLLECTOR_HPP
// mapnik
#include <mapnik/filter.hpp>
#include <mapnik/expression.hpp>
#include <mapnik/feature_layer_desc.hpp>
#include <mapnik/rule.hpp>
// stl
#include <set>
#include <iostream>
namespace mapnik {
struct symbolizer_attributes : public boost::static_visitor<>
{
symbolizer_attributes(std::set<std::string>& names)
: names_(names) {}
template <typename T>
void operator () (T const&) const {}
void operator () (text_symbolizer const& sym)
{
names_.insert(sym.get_name());
}
void operator () (shield_symbolizer const& sym)
{
names_.insert(sym.get_name());
}
private:
std::set<std::string>& names_;
};
template <typename FeatureT>
class attribute_collector : public filter_visitor<FeatureT>
{
private:
std::set<std::string>& names_;
public:
attribute_collector(std::set<std::string>& names)
: names_(names) {}
void visit(filter<FeatureT>& /*filter*/)
{
//not interested
}
void visit(expression<FeatureT>& exp)
{
property<FeatureT>* pf;
if ((pf = dynamic_cast<property<FeatureT>*>(&exp)))
{
names_.insert(pf->name());
}
}
void visit(rule_type const& r)
{
const symbolizers& symbols = r.get_symbolizers();
symbolizers::const_iterator symIter=symbols.begin();
symbolizer_attributes attr(names_);
while (symIter != symbols.end())
{
boost::apply_visitor(attr,*symIter++);
}
filter_ptr const& filter = r.get_filter();
filter->accept(*this);
}
virtual ~attribute_collector() {}
private:
// no copying
attribute_collector(attribute_collector const&);
attribute_collector& operator=(attribute_collector const&);
};
}
#endif //ATTRIBUTE_COLLECTOR_HPP