summaryrefslogtreecommitdiffstats
path: root/libshiboken/tmp-referencetopython/sbkconverter.h
blob: edf67394e0c0ad3308d7544ada27b11a4b7f3a4a (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
/*
 * This file is part of the Shiboken Python Bindings Generator project.
 *
 * Copyright (C) 2011 Nokia Corporation and/or its subsidiary(-ies).
 *
 * Contact: PySide team <contact@pyside.org>
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
 */

#ifndef SBK_CONVERTER_H
#define SBK_CONVERTER_H

#include <limits>
#include <Python.h>
#include "shibokenmacros.h"
#include "basewrapper.h"

extern "C"
{

/**
 *  SbkConverter is used to perform type conversions from C++
 *  to Python and vice-versa;.and it is also used for type checking.
 *  SbkConverter is a private structure that must be accessed
 *  using the functions provided by the converter API.
 */
struct SbkConverter;

/**
 *  Given a void pointer to a C++ object, this function must return
 *  the proper Python object. It may be either an existing wrapper
 *  for the C++ object, or a newly create one. Or even the Python
 *  equivalent of the C++ value passed in the argument.
 *
 *  C++ -> Python
 */
typedef PyObject* (*CppToPythonFunc)(const void*);

/**
 *  This function converts a Python object to a C++ value, it may be
 *  a pointer, value, class, container or primitive type, passed via
 *  a void pointer, that will be cast properly inside the function.
 *  This function is usually returned by an IsConvertibleToCppFunc
 *  function, or obtained knowing the type of the Python object input,
 *  thus it will not check the Python object type, and will expect
 *  the void pointer to be pointing to a proper variable.
 *
 *  Python -> C++
 */
typedef void (*PythonToCppFunc)(PyObject*,void*);

/**
 *  Checks if the Python object passed in the argument is convertible to a
 *  C++ type defined inside the function, it returns the converter function
 *  that will transform a Python argument into a C++ value.
 *  It returns NULL if the Python object is not convertible to the C++ type
 *  that the function represents.
 *
 *  Python -> C++ ?
 */
typedef PythonToCppFunc (*IsConvertibleToCppFunc)(PyObject*);

} // extern "C"


namespace Shiboken {
namespace Conversions {

/**
 *  Creates a converter for a wrapper type.
 *  \param type                  A Shiboken.ObjectType that will receive the new converter.
 *  \param toCppPointerConvFunc  Function to retrieve the C++ pointer held by a Python wrapper.
 *  \param toCppPointerCheckFunc Check and return the retriever function of the C++ pointer held by a Python wrapper.
 *  \param pointerToPythonFunc   Function to convert a C++ object to a Python \p type wrapper, keeping their identity.
 *  \param copyToPythonFunc      Function to convert a C++ object to a Python \p type, copying the object.
 *  \returns                     The new converter referred by the wrapper \p type.
 */
LIBSHIBOKEN_API SbkConverter* createConverter(SbkObjectType* type,
                                              PythonToCppFunc toCppPointerConvFunc,
                                              IsConvertibleToCppFunc toCppPointerCheckFunc,
                                              CppToPythonFunc pointerToPythonFunc,
                                              CppToPythonFunc copyToPythonFunc = 0);

LIBSHIBOKEN_API void deleteConverter(SbkConverter* converter);

/**
 *  Adds a new conversion of a Python object to a C++ value.
 *  This is used in copy and implicit conversions.
 */
LIBSHIBOKEN_API void addPythonToCppValueConversion(SbkConverter* converter,
                                                   PythonToCppFunc pythonToCppFunc,
                                                   IsConvertibleToCppFunc isConvertibleToCppFunc);
LIBSHIBOKEN_API void addPythonToCppValueConversion(SbkObjectType* type,
                                                   PythonToCppFunc pythonToCppFunc,
                                                   IsConvertibleToCppFunc isConvertibleToCppFunc);

// C++ -> Python ---------------------------------------------------------------------------

/**
 *  Retrieves the Python wrapper object for the given \p cppIn C++ pointer object.
 *  This function is used only for Value and Object Types.
 *  Example usage:
 *      TYPE* var;
 *      PyObject* pyVar = pointerToPython(SBKTYPE, &var);
 */
LIBSHIBOKEN_API PyObject* pointerToPython(SbkObjectType* type, const void* cppIn);

/**
 *  Retrieves the Python wrapper object for the given C++ value pointed by \p cppIn.
 *  This function is used only for Value Types.
 *  Example usage:
 *      TYPE var;
 *      PyObject* pyVar = copyToPython(SBKTYPE, &var);
 */
LIBSHIBOKEN_API PyObject* copyToPython(SbkObjectType* type, const void* cppIn);

// TODO:WRITEDOCSTRING - used only for Value Types - cppIn must point to a value
/**
 *  Retrieves the Python wrapper object for the given C++ reference pointed by \p cppIn.
 *  This function is used only for Value and Object Types.
 *  It differs from pointerToPython() for not checking for a NULL pointer.
 *  Example usage:
 *      TYPE& var = SOMETHING;
 *      PyObject* pyVar = copyToPython(SBKTYPE, &var);
 */
LIBSHIBOKEN_API PyObject* referenceToPython(SbkObjectType* type, const void* cppIn);

// TODO:WRITEDOCSTRING - used only for Primitives and Containers (and Value Types) - cppIn must point to a primitive, container or value type
/// This is the same as copyToPython function.
LIBSHIBOKEN_API PyObject* toPython(SbkConverter* converter, const void* cppIn);

// Python -> C++ convertibility checks -----------------------------------------------------

// TODO:WRITEDOCSTRING
LIBSHIBOKEN_API PythonToCppFunc isPythonToCppPointerConvertible(SbkObjectType* type, PyObject* pyIn);

// TODO:WRITEDOCSTRING- Returns a Python to C++ conversion function if true, or NULL if false.
LIBSHIBOKEN_API PythonToCppFunc isPythonToCppValueConvertible(SbkObjectType* type, PyObject* pyIn);

// TODO:WRITEDOCSTRING- Returns a Python to C++ conversion function if true, or NULL if false.
LIBSHIBOKEN_API PythonToCppFunc isPythonToCppReferenceConvertible(SbkObjectType* type, PyObject* pyIn);

/// This is the same as isPythonToCppValueConvertible function.
LIBSHIBOKEN_API PythonToCppFunc isPythonToCppConvertible(SbkConverter* converter, PyObject* pyIn);

// Python -> C++ ---------------------------------------------------------------------------

// TODO:WRITEDOCSTRING - function used by the generated [TYPE]_PythonToCpp_[TYPE]_PTR
LIBSHIBOKEN_API void pythonToCppPointer(SbkObjectType* type, PyObject* pyIn, void* cppOut);

// TODO:WRITEDOCSTRING - function used by the generated isConvertible when the PyObject is None,
// making a C++ NULL pointer the result of the toCpp function call.
// DRAFT: When the Python object is a Py_None, it's C++ conversion is always a NULL pointer.
LIBSHIBOKEN_API void nonePythonToCppNullPtr(PyObject*, void* cppOut);

// TODO:WRITEDOCSTRING - tells if \p toCpp is an implicit conversion.
LIBSHIBOKEN_API bool isImplicitConversion(SbkObjectType* type, PythonToCppFunc toCpp);

} } // namespace Shiboken::Conversions

#endif // SBK_CONVERTER_H