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