Python source

git-svn-id: http://www.openmesh.org/svnrepo/OpenMesh/trunk@1171 fdac6126-5c0c-442c-9429-916003d36597

src/Python/Iterator.hh

@@ -0,0 +1,121 @@
+#ifndef OPENMESH_PYTHON_ITERATOR_HH
+#define OPENMESH_PYTHON_ITERATOR_HH
+
+#include "Python/Bindings.hh"
+
+namespace OpenMesh {
+namespace Python {
+
+/**
+ * Wrapper for mesh item iterators.
+ *
+ * This class template is used to wrap mesh item iterators for %Python. It
+ * implements %Python's iterator protocol (the magic methods \_\_iter\_\_ and
+ * \_\_next\_\_).
+ *
+ * @tparam Iterator An iterator type.
+ * @tparam n_items A member function pointer that points to the mesh function
+ * that returns the number of items to iterate over (e.g. n_vertices).
+ */
+template<class Iterator, size_t (OpenMesh::ArrayKernel::*n_items)() const>
+class IteratorWrapperT {
+	public:
+
+		/**
+		 * Constructor
+		 *
+		 * @param _mesh The mesh that contains the items to iterate over.
+		 * @param _hnd The handle of the first item to iterate over.
+		 * @param _skip Specifies if deleted/hidden elements are skipped.
+		 */
+		IteratorWrapperT(const PolyMesh& _mesh, typename Iterator::value_type _hnd, bool _skip = false) :
+			mesh_(_mesh), n_items_(n_items),
+			iterator_(_mesh, _hnd, _skip),
+			iterator_end_(_mesh, typename Iterator::value_type(int((_mesh.*n_items)()))) {
+		}
+
+		/**
+		 * Constructor
+		 *
+		 * @param _mesh The mesh that contains the items to iterate over.
+		 * @param _hnd The handle of the first item to iterate over.
+		 * @param _skip Specifies if deleted/hidden elements are skipped.
+		 */
+		IteratorWrapperT(const TriMesh& _mesh, typename Iterator::value_type _hnd, bool _skip = false) :
+			mesh_(_mesh), n_items_(n_items),
+			iterator_(_mesh, _hnd, _skip),
+			iterator_end_(_mesh, typename Iterator::value_type(int((_mesh.*n_items)()))) {
+		}
+
+		/**
+		 * Implementation of %Python's \_\_iter\_\_ magic method.
+		 *
+		 * @return This iterator.
+		 */
+		IteratorWrapperT iter() const {
+			return *this;
+		}
+
+		/**
+		 * Implementation of %Python's \_\_next\_\_ magic method.
+		 *
+		 * @return The next item. Raises a %Python StopIteration exception if
+		 * there are no more items.
+		 */
+		typename Iterator::value_type next() {
+			if (iterator_ != iterator_end_) {
+				typename Iterator::value_type res = *iterator_;
+				++iterator_;
+				return res;
+			}
+			else {
+				PyErr_SetString(PyExc_StopIteration, "No more data.");
+				boost::python::throw_error_already_set();
+			}
+			return typename Iterator::value_type();
+		}
+
+		/**
+		 * Implementation of %Python's \_\_len\_\_ magic method.
+		 *
+		 * @return The number of items in the mesh.
+		 */
+		unsigned int len() const {
+			return (mesh_.*n_items_)();
+		}
+
+	private:
+		const OpenMesh::PolyConnectivity& mesh_;
+		size_t (OpenMesh::ArrayKernel::*n_items_)() const;
+		Iterator iterator_;
+		Iterator iterator_end_;
+};
+
+/**
+ * Expose an iterator type to %Python.
+ *
+ * @tparam Iterator An iterator type.
+ * @tparam n_items A member function pointer that points to the mesh function
+ * that returns the number of items to iterate over (e.g. n_vertices).
+ *
+ * @param _name The name of the iterator type to be exposed.
+ *
+ * @note %Iterators are wrapped by IteratorWrapperT before they are exposed to
+ * %Python, i.e. they are not exposed directly. This means that iterators
+ * that are passed from %Python to C++ are instances of IteratorWrapperT.
+ */
+template<class Iterator, size_t (OpenMesh::ArrayKernel::*n_items)() const>
+void expose_iterator(const char *_name) {
+	class_<IteratorWrapperT<Iterator, n_items> >(_name, init<PolyMesh&, typename Iterator::value_type, optional<bool> >())
+		.def(init<TriMesh&, typename Iterator::value_type, optional<bool> >())
+		.def("__iter__", &IteratorWrapperT<Iterator, n_items>::iter)
+		.def("__next__", &IteratorWrapperT<Iterator, n_items>::next)
+		.def("__len__", &IteratorWrapperT<Iterator, n_items>::len)
+		.def("next", &IteratorWrapperT<Iterator, n_items>::next)
+		;
+}
+
+} // namespace OpenMesh
+} // namespace Python
+
+#endif