66 lines
2 KiB
C++
66 lines
2 KiB
C++
#ifndef FILE_DATASOURCE_HPP
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#define FILE_DATASOURCE_HPP
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// mapnik
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#include <mapnik/datasource.hpp>
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#include <mapnik/params.hpp>
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#include <mapnik/query.hpp>
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#include <mapnik/feature.hpp>
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#include <mapnik/box2d.hpp>
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#include <mapnik/coord.hpp>
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#include <mapnik/feature_layer_desc.hpp>
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// boost
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#include <boost/optional.hpp>
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#include <boost/shared_ptr.hpp>
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// stl
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#include <string>
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class hello_datasource : public mapnik::datasource
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{
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public:
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// constructor
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// arguments must not change
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hello_datasource(mapnik::parameters const& params);
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// destructor
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virtual ~hello_datasource ();
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// mandatory: type of the plugin, used to match at runtime
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mapnik::datasource::datasource_t type() const;
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// mandatory: name of the plugin
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static const char * name();
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// mandatory: function to query features by box2d
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// this is called when rendering, specifically in feature_style_processor.hpp
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mapnik::featureset_ptr features(mapnik::query const& q) const;
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// mandatory: function to query features by point (coord2d)
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// not used by rendering, but available to calling applications
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mapnik::featureset_ptr features_at_point(mapnik::coord2d const& pt, double tol = 0) const;
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// mandatory: return the box2d of the datasource
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// called during rendering to determine if the layer should be processed
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mapnik::box2d<double> envelope() const;
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// mandatory: optionally return the overal geometry type of the datasource
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boost::optional<mapnik::datasource::geometry_t> get_geometry_type() const;
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// mandatory: return the layer descriptor
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mapnik::layer_descriptor get_descriptor() const;
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private:
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// recommended - do intialization in a so-named init function
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// to reduce code in constructor
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void init(mapnik::parameters const& params);
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// recommended naming convention of datasource members:
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// name_, type_, extent_, and desc_
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static const std::string name_;
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mutable mapnik::layer_descriptor desc_;
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mutable mapnik::box2d<double> extent_;
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};
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#endif // FILE_DATASOURCE_HPP
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