mapnik/bindings/python/mapnik_layer.cpp
2012-03-12 16:15:56 +00:00

334 lines
13 KiB
C++

/*****************************************************************************
*
* This file is part of Mapnik (c++ mapping toolkit)
*
* Copyright (C) 2006 Artem Pavlenko, Jean-Francois Doyon
*
* 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: mapnik_layer.cc 17 2005-03-08 23:58:43Z pavlenko $
// boost
#include <boost/python.hpp>
#include <boost/python/detail/api_placeholder.hpp>
#include <boost/python/suite/indexing/vector_indexing_suite.hpp>
// mapnik
#include <mapnik/layer.hpp>
#include <mapnik/datasource.hpp>
#include <mapnik/datasource_cache.hpp>
using mapnik::layer;
using mapnik::parameters;
using mapnik::datasource_cache;
struct layer_pickle_suite : boost::python::pickle_suite
{
static boost::python::tuple
getinitargs(const layer& l)
{
return boost::python::make_tuple(l.name(),l.srs());
}
static boost::python::tuple
getstate(const layer& l)
{
boost::python::list s;
std::vector<std::string> const& style_names = l.styles();
for (unsigned i = 0; i < style_names.size(); ++i)
{
s.append(style_names[i]);
}
return boost::python::make_tuple(l.clear_label_cache(),l.min_zoom(),l.max_zoom(),l.queryable(),l.datasource_parameters(),l.cache_features(),s);
}
static void
setstate (layer& l, boost::python::tuple state)
{
using namespace boost::python;
if (len(state) != 9)
{
PyErr_SetObject(PyExc_ValueError,
("expected 9-item tuple in call to __setstate__; got %s"
% state).ptr()
);
throw_error_already_set();
}
l.set_clear_label_cache(extract<bool>(state[0]));
l.set_min_zoom(extract<double>(state[1]));
l.set_max_zoom(extract<double>(state[2]));
l.set_queryable(extract<bool>(state[3]));
mapnik::parameters params = extract<parameters>(state[4]);
l.set_datasource_parameters(params);
boost::python::list s = extract<boost::python::list>(state[5]);
for (int i=0;i<len(s);++i)
{
l.add_style(extract<std::string>(s[i]));
}
l.set_cache_features(extract<bool>(state[6]));
}
};
std::vector<std::string> & (mapnik::layer::*_styles_)() = &mapnik::layer::styles;
void set_datasource_parameters(layer & lyr, boost::python::dict const& d)
{
mapnik::parameters params;
boost::python::list keys = d.keys();
for (int i=0;i<len(keys);++i)
{
boost::python::extract<std::string> k(keys[i]);
if (k.check())
{
boost::python::object obj = d[keys[i]];
boost::python::extract<std::string> str_val(obj);
if (str_val.check())
{
params.insert(std::make_pair(k(),str_val()));
continue;
}
boost::python::extract<int> int_val(obj);
if (int_val.check())
{
params.insert(std::make_pair(k(),int_val()));
continue;
}
boost::python::extract<double> dbl_val(obj);
if (dbl_val.check())
{
params.insert(std::make_pair(k(),dbl_val()));
}
}
}
lyr.set_datasource_parameters(params);
}
void export_layer()
{
using namespace boost::python;
class_<std::vector<std::string> >("Names")
.def(vector_indexing_suite<std::vector<std::string>,true >())
;
class_<layer>("Layer", "A Mapnik map layer.", init<std::string const&,optional<std::string const&> >(
"Create a Layer with a named string and, optionally, an srs string.\n"
"\n"
"The srs can be either a Proj.4 epsg code ('+init=epsg:<code>') or\n"
"of a Proj.4 literal ('+proj=<literal>').\n"
"If no srs is specified it will default to '+proj=longlat +ellps=WGS84 +datum=WGS84 +no_defs'\n"
"\n"
"Usage:\n"
">>> from mapnik import Layer\n"
">>> lyr = Layer('My Layer','+proj=longlat +ellps=WGS84 +datum=WGS84 +no_defs')\n"
">>> lyr\n"
"<mapnik._mapnik.Layer object at 0x6a270>\n"
))
.def_pickle(layer_pickle_suite())
.def("envelope",&layer::envelope,
"Return the geographic envelope/bounding box."
"\n"
"Determined based on the layer datasource.\n"
"\n"
"Usage:\n"
">>> from mapnik import Layer\n"
">>> lyr = Layer('My Layer','+proj=longlat +ellps=WGS84 +datum=WGS84 +no_defs')\n"
">>> lyr.envelope()\n"
"box2d(-1.0,-1.0,0.0,0.0) # default until a datasource is loaded\n"
)
.def("visible", &layer::visible,
"Return True if this layer's data is active and visible at a given scale.\n"
"\n"
"Otherwise returns False.\n"
"Accepts a scale value as an integer or float input.\n"
"Will return False if:\n"
"\tscale >= minzoom - 1e-6\n"
"\tor:\n"
"\tscale < maxzoom + 1e-6\n"
"\n"
"Usage:\n"
">>> from mapnik import Layer\n"
">>> lyr = Layer('My Layer','+proj=longlat +ellps=WGS84 +datum=WGS84 +no_defs')\n"
">>> lyr.visible(1.0/1000000)\n"
"True\n"
">>> lyr.active = False\n"
">>> lyr.visible(1.0/1000000)\n"
"False\n"
)
.add_property("active",
&layer::active,
&layer::set_active,
"Get/Set whether this layer is active and will be rendered.\n"
"\n"
"Usage:\n"
">>> from mapnik import Layer\n"
">>> lyr = Layer('My Layer','+proj=longlat +ellps=WGS84 +datum=WGS84 +no_defs')\n"
">>> lyr.active\n"
"True # Active by default\n"
">>> lyr.active = False # set False to disable layer rendering\n"
">>> lyr.active\n"
"False\n"
)
.add_property("clear_label_cache",
&layer::clear_label_cache,
&layer::set_clear_label_cache,
"Get/Set whether to clear the label collision detector cache for this layer during rendering\n"
"\n"
"Usage:\n"
">>> lyr.clear_label_cache\n"
"False # False by default, meaning label positions from other layers will impact placement \n"
">>> lyr.clear_label_cache = True # set to True to clear the label collision detector cache\n"
)
.add_property("cache_features",
&layer::cache_features,
&layer::set_cache_features,
"Get/Set whether features should be cached during rendering if used between multiple styles\n"
"\n"
"Usage:\n"
">>> lyr.cache_features\n"
"False # False by default\n"
">>> lyr.cache_features = True # set to True to enable feature caching\n"
)
.def("datasource",&layer::datasource,
"The datasource attached to this layer.\n"
)
.add_property("datasource_parameters",
make_function(&layer::datasource_parameters,return_value_policy<copy_const_reference>()),
set_datasource_parameters,
"The datasource parameters attached to this layer.\n"
"\n"
"Usage:\n"
">>> from mapnik import Layer, Datasource\n"
">>> lyr = Layer('My Layer','+proj=longlat +ellps=WGS84 +datum=WGS84 +no_defs')\n"
">>> lyr.datasource_parameters = {'type':'shape','file':'world_borders'}\n"
">>> lyr.datasource\n"
"<mapnik.Datasource object at 0x65470>\n"
)
.add_property("maxzoom",
&layer::max_zoom,
&layer::set_max_zoom,
"Get/Set the maximum zoom lever of the layer.\n"
"\n"
"Usage:\n"
">>> from mapnik import Layer\n"
">>> lyr = Layer('My Layer','+proj=longlat +ellps=WGS84 +datum=WGS84 +no_defs')\n"
">>> lyr.maxzoom\n"
"1.7976931348623157e+308 # default is the numerical maximum\n"
">>> lyr.maxzoom = 1.0/1000000\n"
">>> lyr.maxzoom\n"
"9.9999999999999995e-07\n"
)
.add_property("minzoom",
&layer::min_zoom,
&layer::set_min_zoom,
"Get/Set the minimum zoom lever of the layer.\n"
"\n"
"Usage:\n"
">>> from mapnik import Layer\n"
">>> lyr = Layer('My Layer','+proj=longlat +ellps=WGS84 +datum=WGS84 +no_defs')\n"
">>> lyr.minzoom # default is 0\n"
"0.0\n"
">>> lyr.minzoom = 1.0/1000000\n"
">>> lyr.minzoom\n"
"9.9999999999999995e-07\n"
)
.add_property("name",
make_function(&layer::name, return_value_policy<copy_const_reference>()),
&layer::set_name,
"Get/Set the name of the layer.\n"
"\n"
"Usage:\n"
">>> from mapnik import Layer\n"
">>> lyr = Layer('My Layer','+proj=longlat +ellps=WGS84 +datum=WGS84 +no_defs')\n"
">>> lyr.name\n"
"'My Layer'\n"
">>> lyr.name = 'New Name'\n"
">>> lyr.name\n"
"'New Name'\n"
)
.add_property("queryable",
&layer::queryable,
&layer::set_queryable,
"Get/Set whether this layer is queryable.\n"
"\n"
"Usage:\n"
">>> from mapnik import layer\n"
">>> lyr = layer('My layer','+proj=longlat +ellps=WGS84 +datum=WGS84 +no_defs')\n"
">>> lyr.queryable\n"
"False # Not queryable by default\n"
">>> lyr.queryable = True\n"
">>> lyr.queryable\n"
"True\n"
)
.add_property("srs",
make_function(&layer::srs,return_value_policy<copy_const_reference>()),
&layer::set_srs,
"Get/Set the SRS of the layer.\n"
"\n"
"Usage:\n"
">>> from mapnik import layer\n"
">>> lyr = layer('My layer','+proj=longlat +ellps=WGS84 +datum=WGS84 +no_defs')\n"
">>> lyr.srs\n"
"'+proj=longlat +ellps=WGS84 +datum=WGS84 +no_defs' # The default srs if not initialized with custom srs\n"
">>> # set to google mercator with Proj.4 literal\n"
"... \n"
">>> lyr.srs = '+proj=merc +a=6378137 +b=6378137 +lat_ts=0.0 +lon_0=0.0 +x_0=0.0 +y_0=0 +k=1.0 +units=m +nadgrids=@null +no_defs +over'\n"
)
.add_property("styles",
make_function(_styles_,return_value_policy<reference_existing_object>()),
"The styles list attached to this layer.\n"
"\n"
"Usage:\n"
">>> from mapnik import layer\n"
">>> lyr = layer('My layer','+proj=longlat +ellps=WGS84 +datum=WGS84 +no_defs')\n"
">>> lyr.styles\n"
"<mapnik._mapnik.Names object at 0x6d3e8>\n"
">>> len(lyr.styles)\n"
"0\n # no styles until you append them\n"
"lyr.styles.append('My Style') # mapnik uses named styles for flexibility\n"
">>> len(lyr.styles)\n"
"1\n"
">>> lyr.styles[0]\n"
"'My Style'\n"
)
;
}