NameIndexInterface.h

00001 /*
00002  * This source file is part of libRocket, the HTML/CSS Interface Middleware
00003  *
00004  * For the latest information, see http://www.librocket.com
00005  *
00006  * Copyright (c) 2008-2010 CodePoint Ltd, Shift Technology Ltd
00007  *
00008  * Permission is hereby granted, free of charge, to any person obtaining a copy
00009  * of this software and associated documentation files (the "Software"), to deal
00010  * in the Software without restriction, including without limitation the rights
00011  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
00012  * copies of the Software, and to permit persons to whom the Software is
00013  * furnished to do so, subject to the following conditions:
00014  *
00015  * The above copyright notice and this permission notice shall be included in
00016  * all copies or substantial portions of the Software.
00017  * 
00018  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
00019  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
00020  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
00021  * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
00022  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
00023  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
00024  * THE SOFTWARE.
00025  *
00026  */
00027 
00028 #ifndef ROCKETCOREPYTHONNAMEINDEXINTERFACE_H
00029 #define ROCKETCOREPYTHONNAMEINDEXINTERFACE_H
00030 
00031 #include <Rocket/Core/Python/Utilities.h>
00032 
00033 namespace Rocket {
00034 namespace Core {
00035 namespace Python {
00036 
00037 template < typename HostType >
00038 class NameAccessorInvalid
00039 {
00040 public:
00041         python::object operator()(HostType& host, const char* name)
00042         {
00043                 PyErr_SetString(PyExc_KeyError, "Invalid key.");
00044                 python::throw_error_already_set();
00045 
00046                 return python::object();
00047         }
00048 };
00049 
00056 template < typename HostType, typename LengthAccessor, typename IndexAccessor, typename NameAccessor = NameAccessorInvalid< HostType > >
00057 class NameIndexInterface : public python::def_visitor< NameIndexInterface< HostType, LengthAccessor, IndexAccessor, NameAccessor > >
00058 {
00059 public:
00060         NameIndexInterface()
00061         {
00062         }
00063 
00064         ~NameIndexInterface()
00065         {
00066         }
00067 
00069         template < typename ClassType >
00070         void visit(ClassType& _class) const
00071         {
00072                 _class.def("__getitem__", &NameIndexInterface< HostType, LengthAccessor, IndexAccessor, NameAccessor >::GetItem);
00073                 _class.def("__len__", &NameIndexInterface< HostType, LengthAccessor, IndexAccessor, NameAccessor >::Len);
00074         }
00075 
00077         static python::object GetItem(HostType& host, python::object key)
00078         {
00079                 static NameAccessor name_accessor;
00080                 static LengthAccessor length_accessor;
00081                 static IndexAccessor index_accessor;
00082 
00083                 if (PyString_Check(key.ptr()))
00084                 {
00085                         return Rocket::Core::Python::Utilities::MakeObject(name_accessor(host, PyString_AsString(key.ptr())));
00086                 }
00087                 else if (PyInt_Check(key.ptr()))
00088                 {
00089                         int index = PyInt_AsLong(key.ptr());
00090 
00091                         // Support indexing from both ends.
00092                         if (index < 0)
00093                                 index = length_accessor(host) + index;
00094 
00095                         // Throw exception if we're out of range, this is required to support python iteration.
00096                         if (index >= length_accessor(host))
00097                         {
00098                                 PyErr_SetString(PyExc_IndexError, "Index out of range.");
00099                                 python::throw_error_already_set();
00100                         }
00101 
00102                         return Rocket::Core::Python::Utilities::MakeObject(index_accessor(host, index));
00103                 }
00104 
00105                 PyErr_SetString(PyExc_KeyError, "Invalid key.");
00106                 python::throw_error_already_set();
00107 
00108                 return python::object();
00109         }
00110 
00112         static int Len(HostType& host)
00113         {
00114                 static LengthAccessor length_accessor;
00115                 return length_accessor(host);
00116         }
00117 };
00118 
00119 }
00120 }
00121 }
00122 
00123 #endif