add pickling support for point_symbolizer and expose the filename property (patch from mishok13 - thanks) - closes #114, addresses #345

bindings/python/mapnik_point_symbolizer.cpp

@@ -22,17 +22,80 @@
 //$Id$
 
 #include <boost/python.hpp>
+#include <mapnik/graphics.hpp>
+#include <mapnik/image_util.hpp>
 #include <mapnik/point_symbolizer.hpp>
 
+
+using mapnik::point_symbolizer;
+using mapnik::symbolizer_with_image;
+
+struct point_symbolizer_pickle_suite : boost::python::pickle_suite
+{
+   static boost::python::tuple
+   getinitargs(const point_symbolizer& p)
+   {
+      boost::shared_ptr<mapnik::ImageData32> img = p.get_image();
+      const std::string & filename = p.get_filename();
+      
+      if ( ! filename.empty() ) {
+          return boost::python::make_tuple(filename,mapnik::guess_type(filename),img->width(),img->height());
+      } else {
+          return boost::python::make_tuple();
+      }
+      
+   }
+
+   static  boost::python::tuple
+   getstate(const point_symbolizer& p)
+   {
+        return boost::python::make_tuple(p.get_allow_overlap(),p.get_opacity());
+   }
+
+   static void
+   setstate (point_symbolizer& p, boost::python::tuple state)
+   {
+        using namespace boost::python;
+        if (len(state) != 2)
+        {
+            PyErr_SetObject(PyExc_ValueError,
+                         ("expected 2-item tuple in call to __setstate__; got %s"
+                          % state).ptr()
+            );
+            throw_error_already_set();
+        }
+                
+        p.set_allow_overlap(extract<bool>(state[0]));
+        p.set_opacity(extract<float>(state[1]));
+        
+   }
+
+};
+
+namespace  
+{ 
+    using namespace boost::python;
+
+	  const char *get_filename(mapnik::point_symbolizer& symbolizer) 
+	  { 
+	      return symbolizer.get_filename().c_str(); 
+	  } 
+}
+
 void export_point_symbolizer()
 {
     using namespace boost::python;
-    using mapnik::point_symbolizer;
     
     class_<point_symbolizer>("PointSymbolizer",
                              init<>("Default Point Symbolizer - 4x4 black square"))
         .def (init<std::string const&,
               std::string const&,unsigned,unsigned>("TODO"))
+        .def_pickle(point_symbolizer_pickle_suite())
+        .add_property("filename",
+            // DS - Using workaround as the normal make_function does not work for unknown reasons...
+            //make_function(&point_symbolizer::get_filename,return_value_policy<copy_const_reference>()),
+            get_filename,
+            &point_symbolizer::set_filename)   
         .add_property("allow_overlap",
               &point_symbolizer::get_allow_overlap,
               &point_symbolizer::set_allow_overlap)

tests/python_tests/object_test.py

@@ -45,10 +45,12 @@ def test_pointsymbolizer_missing_image():
 
 # PointSymbolizer pickling
 def test_pointsymbolizer_pickle():
-    raise Todo("PointSymbolizer does not support pickling yet.")
-    #p = mapnik.PointSymbolizer()
-    #p2 = pickle.loads(pickle.dumps(p,pickle.HIGHEST_PROTOCOL))
-    #eq_(p2, p)    
+    p = mapnik.PointSymbolizer("../data/images/dummy.png", "png", 16, 16)
+    p2 = pickle.loads(pickle.dumps(p,pickle.HIGHEST_PROTOCOL))
+    # image type, width, and height only used in contructor...
+    eq_(p.filename, p2.filename)
+    eq_(p.allow_overlap, p2.allow_overlap)
+    eq_(p.opacity, p2.opacity)
 
 # PolygonSymbolizer initialization
 def test_polygonsymbolizer_init():