pyAnnotatedBoolResult.h
1 //
2 // Copyright 2016 Pixar
3 //
4 // Licensed under the Apache License, Version 2.0 (the "Apache License")
5 // with the following modification; you may not use this file except in
6 // compliance with the Apache License and the following modification to it:
7 // Section 6. Trademarks. is deleted and replaced with:
8 //
9 // 6. Trademarks. This License does not grant permission to use the trade
10 // names, trademarks, service marks, or product names of the Licensor
11 // and its affiliates, except as required to comply with Section 4(c) of
12 // the License and to reproduce the content of the NOTICE file.
13 //
14 // You may obtain a copy of the Apache License at
15 //
16 // http://www.apache.org/licenses/LICENSE-2.0
17 //
18 // Unless required by applicable law or agreed to in writing, software
19 // distributed under the Apache License with the above modification is
20 // distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
21 // KIND, either express or implied. See the Apache License for the specific
22 // language governing permissions and limitations under the Apache License.
23 //
24 #ifndef PXR_BASE_TF_PY_ANNOTATED_BOOL_RESULT_H
25 #define PXR_BASE_TF_PY_ANNOTATED_BOOL_RESULT_H
26 
27 #include "pxr/pxr.h"
28 
29 #include "pxr/base/tf/py3Compat.h"
30 #include "pxr/base/tf/pyLock.h"
31 #include "pxr/base/tf/pyUtils.h"
32 
33 #include <boost/operators.hpp>
34 #include <boost/python/class.hpp>
35 #include <boost/python/operators.hpp>
36 #include <boost/python/return_by_value.hpp>
37 
38 #include <string>
39 
40 PXR_NAMESPACE_OPEN_SCOPE
41 
42 template <class Annotation>
43 struct TfPyAnnotatedBoolResult :
44  boost::equality_comparable<TfPyAnnotatedBoolResult<Annotation>, bool>
45 {
46  TfPyAnnotatedBoolResult() {}
47 
48  TfPyAnnotatedBoolResult(bool val, Annotation const &annotation) :
49  _val(val), _annotation(annotation) {}
50 
51  bool GetValue() const {
52  return _val;
53  }
54 
55  Annotation const &GetAnnotation() const {
56  return _annotation;
57  }
58 
59  std::string GetRepr() const {
60  return GetValue() ? "True" :
61  "(False, " + TfPyRepr(GetAnnotation()) + ")";
62  }
63 
65  bool operator==(bool rhs) const {
66  return _val == rhs;
67  }
68 
69  template <class Derived>
70  static boost::python::class_<Derived>
71  Wrap(char const *name, char const *annotationName) {
72  typedef TfPyAnnotatedBoolResult<Annotation> This;
73  using namespace boost::python;
74  TfPyLock lock;
75  return class_<Derived>(name, init<bool, Annotation>())
76  .def(TfPyBoolBuiltinFuncName, &Derived::GetValue)
77  .def("__repr__", &Derived::GetRepr)
78  .def(self == bool())
79  .def(self != bool())
80  .def(bool() == self)
81  .def(bool() != self)
82  // Use a helper function. We'd like to def_readonly the
83  // _annotation member but there are two problems with that.
84  // First, we can't control the return_value_policy and if the
85  // Annotation type has a custom to-Python converter then the
86  // def_readonly return_value_policy of return_internal_reference
87  // won't work since the object needs conversion. Second, if we
88  // try to use GetAnnotation() with add_property then we'll get
89  // a failure at runtime because Python has a Derived but
90  // GetAnnotation takes a TfPyAnnotatedBoolResult<Annotation>
91  // and boost python doesn't know the former is-a latter because
92  // TfPyAnnotatedBoolResult<Annotation> is not wrapped.
93  //
94  // So we provide a templated static method that takes a Derived
95  // and returns Annotation by value. We can add_property that
96  // with no problem.
97  .add_property(annotationName, &This::_GetAnnotation<Derived>)
98  .def("__getitem__", &This::_GetItem<Derived>)
99  ;
100  }
101 
102  using AnnotationType = Annotation;
103 
104 private:
105  // Helper function for wrapper.
106  template <class Derived>
107  static Annotation _GetAnnotation(const Derived& x)
108  {
109  return x.GetAnnotation();
110  }
111 
112  template <class Derived>
113  static boost::python::object _GetItem(const Derived& x, int i)
114  {
115  if (i == 0) {
116  return boost::python::object(x._val);
117  }
118  if (i == 1) {
119  return boost::python::object(x._annotation);
120  }
121 
122  PyErr_SetString(PyExc_IndexError, "Index must be 0 or 1.");
123  boost::python::throw_error_already_set();
124 
125  return boost::python::object();
126  }
127 
128 private:
129  bool _val;
130  Annotation _annotation;
131 
132 };
133 
135 template <class Annotation>
136 bool operator==(bool lhs, TfPyAnnotatedBoolResult<Annotation>& rhs)
137 {
138  return rhs == lhs;
139 }
140 
142 template <class Annotation>
143 bool operator!=(bool lhs, TfPyAnnotatedBoolResult<Annotation>& rhs)
144 {
145  return rhs != lhs;
146 }
147 
148 PXR_NAMESPACE_CLOSE_SCOPE
149 
150 #endif // PXR_BASE_TF_PY_ANNOTATED_BOOL_RESULT_H
Compatibility code for supporting python 2 and 3.
Miscellaneous Utilities for dealing with script.
std::string TfPyRepr(T const &t)
Return repr(t).
Definition: pyUtils.h:138
Convenience class for accessing the Python Global Interpreter Lock.
Definition: pyLock.h:122
VT_API bool operator==(VtDictionary const &, VtDictionary const &)
Equality comparison.