PropertyManager.hh 9.99 KB
Newer Older
1
2
3
/*===========================================================================*\
 *                                                                           *
 *                               OpenMesh                                    *
Jan Möbius's avatar
Jan Möbius committed
4
 *      Copyright (C) 2001-2012 by Computer Graphics Group, RWTH Aachen      *
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
 *                           www.openmesh.org                                *
 *                                                                           *
 *---------------------------------------------------------------------------*
 *  This file is part of OpenMesh.                                           *
 *                                                                           *
 *  OpenMesh 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 3 of           *
 *  the License, or (at your option) any later version with the              *
 *  following exceptions:                                                    *
 *                                                                           *
 *  If other files instantiate templates or use macros                       *
 *  or inline functions from this file, or you compile this file and         *
 *  link it with other files to produce an executable, this file does        *
 *  not by itself cause the resulting executable to be covered by the        *
 *  GNU Lesser General Public License. This exception does not however       *
 *  invalidate any other reasons why the executable file might be            *
 *  covered by the GNU Lesser General Public License.                        *
 *                                                                           *
 *  OpenMesh 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 LesserGeneral Public          *
 *  License along with OpenMesh.  If not,                                    *
 *  see <http://www.gnu.org/licenses/>.                                      *
 *                                                                           *
\*===========================================================================*/

/*===========================================================================*\
 *                                                                           *
 *   $Revision$                                                              *
 *   $Date$                                                                  *
 *                                                                           *
\*===========================================================================*/

#ifndef PROPERTYMANAGER_HH_
#define PROPERTYMANAGER_HH_

#include <sstream>
46
#include <stdexcept>
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

namespace OpenMesh {

/**
 * This class is intended to manage the lifecycle of properties.
 * It also defines convenience operators to access the encapsulated
 * property's value.
 *
 * Usage example:
 *
 * \code
 * TriMesh mesh;
 * PropertyManager<VPropHandleT<bool>, MeshT> visited(mesh, "visited.plugin-example.i8.informatik.rwth-aachen.de");
 *
 * for (TriMesh::VertexIter vh_it = mesh.begin(); ... ; ...) {
 *     if (!visited[*vh_it]) {
 *         visitComponent(mesh, *vh_it, visited);
 *     }
 * }
 * \endcode
 *
 */
template<typename PROPTYPE, typename MeshT>
class PropertyManager {
    private:
        /**
73
         * Noncopyable because there aren't no straightforward copy semantics.
74
75
76
77
         */
        PropertyManager(const PropertyManager&);

        /**
78
         * Noncopyable because there aren't no straightforward copy semantics.
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
         */
        const PropertyManager& operator=(const PropertyManager&);

    public:
        /**
         * Constructor.
         *
         * Throws an \p std::runtime_error if \p existing is true and
         * no property named \p propname of the appropriate property type
         * exists.
         *
         * @param mesh The mesh on which to create the property.
         * @param propname The name of the property.
         * @param existing If false, a new property is created and its lifecycle is managed (i.e.
         * the property is deleted upon destruction of the PropertyManager instance). If true,
         * the instance merely acts as a convenience wrapper around an existing property with no
         * lifecycle management whatsoever.
         */
        PropertyManager(MeshT &mesh, const char *propname, bool existing = false) : mesh_(&mesh), retain_(existing) {
            if (existing) {
                if (!mesh_->get_property_handle(prop_, propname)) {
                    std::ostringstream oss;
                    oss << "Requested property handle \"" << propname << "\" does not exist.";
                    throw std::runtime_error(oss.str());
                }
            } else {
                mesh_->add_property(prop_, propname);
            }
        }

109
110
111
        PropertyManager() : mesh_(0), retain_(false) {
        }

112
113
114
115
        ~PropertyManager() {
            deleteProperty();
        }

116
117
118
119
120
121
        void swap(PropertyManager &rhs) {
            std::swap(mesh_, rhs.mesh_);
            std::swap(prop_, rhs.prop_);
            std::swap(retain_, rhs.retain_);
        }

122
123
124
125
126
        static bool propertyExists(MeshT &mesh, const char *propname) {
            PROPTYPE dummy;
            return mesh.get_property_handle(dummy, propname);
        }

127
128
129
130
131
        bool isValid() const { return mesh_ != 0; }
        operator bool() const { return isValid(); }

        const PROPTYPE &getRawProperty() const { return prop_; }

132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
#if __cplusplus > 199711L or __GXX_EXPERIMENTAL_CXX0X__
        /**
         * Move constructor. Transfers ownership (delete responsibility).
         */
        PropertyManager(PropertyManager &&rhs) : mesh_(rhs.mesh_), prop_(rhs.prop_), retain_(rhs.retain_) {
            rhs.retain_ = true;
        }

        /**
         * Move assignment. Transfers ownership (delete responsibility).
         */
        PropertyManager &operator=(PropertyManager &&rhs) {

            deleteProperty();

            mesh_ = rhs.mesh_;
            prop_ = rhs.prop_;
            retain_ = rhs.retain_;
            rhs.retain_ = true;

            return *this;
        }
154
155
156
157
158
159
160
161
162
163
164
165

        /**
         * Create a property manager for the supplied property and mesh.
         * If the property doesn't exist, it is created. In any case,
         * lifecycle management is disabled.
         */
        static PropertyManager createIfNotExists(MeshT &mesh, const char *propname) {
            PROPTYPE dummy_prop;
            PropertyManager pm(mesh, propname, mesh.get_property_handle(dummy_prop, propname));
            pm.retain();
            return std::move(pm);
        }
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203

#else
        class Proxy {
            private:
                Proxy(MeshT *mesh_, PROPTYPE prop_, bool retain_) :
                    mesh_(mesh_), prop_(prop_), retain_(retain_) {}
                MeshT *mesh_;
                PROPTYPE prop_;
                bool retain_;

                friend class PropertyManager;
        };

        operator Proxy() {
            Proxy p(mesh_, prop_, retain_);
            mesh_ = 0;
            retain_ = true;
            return p;
        }

        PropertyManager(Proxy p) : mesh_(p.mesh_), prop_(p.prop_), retain_(p.retain_) {}

        PropertyManager &operator=(Proxy p) {
            PropertyManager(p).swap(*this);
            return *this;
        }

        /**
         * Create a property manager for the supplied property and mesh.
         * If the property doesn't exist, it is created. In any case,
         * lifecycle management is disabled.
         */
        static Proxy createIfNotExists(MeshT &mesh, const char *propname) {
            PROPTYPE dummy_prop;
            PropertyManager pm(mesh, propname, mesh.get_property_handle(dummy_prop, propname));
            pm.retain();
            return (Proxy)pm;
        }
204
205
206
207
208
209
210
211
#endif

        /**
         * \brief Disable lifecycle management for this property.
         *
         * If this method is called, the encapsulated property will not be deleted
         * upon destruction of the PropertyManager instance.
         */
212
213
        inline void retain(bool doRetain = true) {
            retain_ = doRetain;
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
        }

        /**
         * Access the encapsulated property.
         */
        inline PROPTYPE &operator* () {
            return prop_;
        }

        /**
         * Access the encapsulated property.
         */
        inline const PROPTYPE &operator* () const {
            return prop_;
        }

        /**
         * Enables convenient access to the encapsulated property.
         *
         * For a usage example see this class' documentation.
         *
         * @param handle A handle of the appropriate handle type. (I.e. \p VertexHandle for \p VPropHandleT, etc.)
         */
        template<typename HandleType>
        inline typename PROPTYPE::reference operator[] (const HandleType &handle) {
            return mesh_->property(prop_, handle);
        }

        /**
         * Enables convenient access to the encapsulated property.
         *
         * For a usage example see this class' documentation.
         *
         * @param handle A handle of the appropriate handle type. (I.e. \p VertexHandle for \p VPropHandleT, etc.)
         */
        template<typename HandleType>
        inline typename PROPTYPE::const_reference operator[] (const HandleType &handle) const {
            return mesh_->property(prop_, handle);
        }

    private:
        void deleteProperty() {
            if (!retain_)
                mesh_->remove_property(prop_);
        }

    private:
        MeshT *mesh_;
        PROPTYPE prop_;
        bool retain_;
};

} /* namespace OpenMesh */
#endif /* PROPERTYMANAGER_HH_ */