mapnik/include/mapnik/attribute_collector.hpp
2017-05-05 13:02:01 +02:00

311 lines
9.1 KiB
C++

/*****************************************************************************
*
* This file is part of Mapnik (c++ mapping toolkit)
*
* Copyright (C) 2017 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
*
*****************************************************************************/
#ifndef MAPNIK_ATTRIBUTE_COLLECTOR_HPP
#define MAPNIK_ATTRIBUTE_COLLECTOR_HPP
// mapnik
#include <mapnik/transform/transform_processor.hpp>
#include <mapnik/util/noncopyable.hpp>
#include <mapnik/attribute.hpp>
#include <mapnik/symbolizer.hpp>
#include <mapnik/expression.hpp> // for expression_ptr, etc
#include <mapnik/expression_node.hpp>
#include <mapnik/parse_path.hpp> // for path_processor_type
#include <mapnik/path_expression.hpp> // for path_expression_ptr
#include <mapnik/text/placements/base.hpp> // for text_placements
#include <mapnik/image_scaling.hpp>
#include <mapnik/group/group_symbolizer_properties.hpp>
#include <mapnik/group/group_rule.hpp>
#include <mapnik/util/conversions.hpp>
#include <mapnik/util/variant.hpp>
#pragma GCC diagnostic push
#include <mapnik/warning_ignore.hpp>
#include <boost/algorithm/string/replace.hpp>
#pragma GCC diagnostic pop
// stl
#include <set>
#include <functional> // std::ref
namespace mapnik {
template <typename Container>
struct expression_attributes
{
explicit expression_attributes(Container& names)
: names_(names) {}
void operator() (attribute const& attr) const
{
names_.emplace(attr.name());
}
template <typename Tag>
void operator() (binary_node<Tag> const& x) const
{
util::apply_visitor(*this, x.left);
util::apply_visitor(*this, x.right);
}
template <typename Tag>
void operator() (unary_node<Tag> const& x) const
{
util::apply_visitor(*this, x.expr);
}
void operator() (regex_match_node const& x) const
{
util::apply_visitor(*this, x.expr);
}
void operator() (regex_replace_node const& x) const
{
util::apply_visitor(*this, x.expr);
}
template <typename T>
void operator() (T const&) const {}
private:
Container& names_;
};
class group_attribute_collector : public util::noncopyable
{
private:
std::set<std::string>& names_;
bool expand_index_columns_;
public:
group_attribute_collector(std::set<std::string>& names,
bool expand_index_columns)
: names_(names),
expand_index_columns_(expand_index_columns) {}
void operator() (group_symbolizer const& sym);
};
template <typename Container>
struct extract_attribute_names
{
explicit extract_attribute_names(Container& names)
: names_(names),
f_attr_(names) {}
void operator() (mapnik::expression_ptr const& expr) const
{
if (expr)
{
util::apply_visitor(f_attr_, *expr);
}
}
void operator() (mapnik::transform_type const& expr) const
{
if (expr)
{
transform_processor_type::collect_attributes(names_, *expr);
}
}
void operator() (mapnik::text_placements_ptr const& expr) const
{
if (expr)
{
expression_set::const_iterator it;
expression_set expressions;
// TODO - optimize (dane)
expr->add_expressions(expressions);
for (it=expressions.begin(); it != expressions.end(); ++it)
{
if (*it) util::apply_visitor(f_attr_, **it);
}
}
}
void operator() (mapnik::path_expression_ptr const& expr) const
{
if (expr)
{
path_processor_type::collect_attributes(*expr,names_);
}
}
template <typename T>
void operator() (T const&) const {}
private:
Container& names_;
expression_attributes<std::set<std::string> > f_attr_;
};
struct symbolizer_attributes
{
symbolizer_attributes(std::set<std::string>& names,
double & filter_factor)
: filter_factor_(filter_factor),
f_attrs_(names),
g_attrs_(names, true) {}
template <typename T>
void operator () (T const& sym)
{
for (auto const& prop : sym.properties)
{
util::apply_visitor(f_attrs_, prop.second);
}
}
void operator () (raster_symbolizer const& sym)
{
boost::optional<double> filter_factor = get_optional<double>(sym, keys::filter_factor);
if (filter_factor)
{
filter_factor_ = *filter_factor;
}
else
{
boost::optional<scaling_method_e> scaling_method = get_optional<scaling_method_e>(sym, keys::scaling);
if (scaling_method && *scaling_method != SCALING_NEAR)
{
filter_factor_ = 2;
}
}
for (auto const& prop : sym.properties)
{
util::apply_visitor(f_attrs_, prop.second);
}
}
void operator () (group_symbolizer const& sym)
{
g_attrs_(sym);
}
private:
double & filter_factor_;
extract_attribute_names<std::set<std::string> > f_attrs_;
group_attribute_collector g_attrs_;
};
class attribute_collector : public util::noncopyable
{
private:
std::set<std::string> & names_;
double filter_factor_;
expression_attributes<std::set<std::string> > f_attr;
public:
attribute_collector(std::set<std::string>& names)
: names_(names),
filter_factor_(1.0),
f_attr(names) {}
template <typename RuleType>
void operator() (RuleType const& r)
{
typename RuleType::symbolizers const& symbols = r.get_symbolizers();
symbolizer_attributes s_attr(names_,filter_factor_);
for (auto const& sym : symbols)
{
util::apply_visitor(std::ref(s_attr), sym);
}
expression_ptr const& expr = r.get_filter();
util::apply_visitor(f_attr,*expr);
}
double get_filter_factor() const
{
return filter_factor_;
}
};
inline void group_attribute_collector::operator() (group_symbolizer const& sym)
{
// find all column names referenced in the group symbolizer
std::set<std::string> group_columns;
attribute_collector column_collector(group_columns);
expression_attributes<std::set<std::string> > rk_attr(group_columns);
// get columns from symbolizer repeat key
expression_ptr repeat_key = get<mapnik::expression_ptr>(sym, keys::repeat_key);
if (repeat_key)
{
util::apply_visitor(rk_attr, *repeat_key);
}
// get columns from child rules and symbolizers
group_symbolizer_properties_ptr props = get<group_symbolizer_properties_ptr>(sym, keys::group_properties);
if (props)
{
for (auto const& rule : props->get_rules())
{
// note that this recurses down on to the symbolizer
// internals too, so we get all free variables.
column_collector(*rule);
// still need to collect repeat key columns
if (rule->get_repeat_key())
{
util::apply_visitor(rk_attr, *(rule->get_repeat_key()));
}
}
}
// get indexed column names
value_integer start = get<value_integer>(sym, keys::start_column);
value_integer end = start + get<value_integer>(sym, keys::num_columns);
for (auto const& col_name : group_columns)
{
if (expand_index_columns_ && col_name.find('%') != std::string::npos)
{
// Note: ignore column name if it is '%' by itself.
// '%' is a special case to access the index value itself,
// rather than acessing indexed columns from data source.
if (col_name.size() > 1)
{
// Indexed column name. add column name for each index value.
for (value_integer col_idx = start; col_idx < end; ++col_idx)
{
std::string col_idx_str;
if (mapnik::util::to_string(col_idx_str,col_idx))
{
std::string col_idx_name = col_name;
boost::replace_all(col_idx_name, "%", col_idx_str);
names_.emplace(col_idx_name);
}
}
}
}
else
{
// This is not an indexed column, or we are ignoring indexes.
// Insert the name as is.
names_.emplace(col_name);
}
}
}
} // namespace mapnik
#endif // MAPNIK_ATTRIBUTE_COLLECTOR_HPP