mapnik/include/attribute_collector.hpp
Artem Pavlenko aed5516197 1. new feature model - based on boost::property_map concept
f = feature(id);
       f["name"] = "what is my name?";
       boost.put(f,"area",123123.4325);
       
2. simplified and corrected value class and operators
3. updated input plug-ins to work with new features
4. add text_symbolizer (getting there:)
5. template version of agg_renderer 
6. attribute_collector how accepts rules 
	(to collect attribute names for text labels)
2006-02-10 17:13:02 +00:00

94 lines
2.4 KiB
C++

/* This file is part of Mapnik (c++ mapping toolkit)
* Copyright (C) 2005 Artem Pavlenko
*
* Mapnik 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 any later version.
*
* This program 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*/
//$Id$
#ifndef ATTRIBUTE_COLLECTOR_HPP
#define ATTRIBUTE_COLLECTOR_HPP
#include "filter.hpp"
#include "expression.hpp"
#include "feature_layer_desc.hpp"
#include "rule.hpp"
#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());
}
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