Fawkes API  Fawkes Development Version
edge_constraint.cpp
1 /***************************************************************************
2  * edge_constraint.cpp - base class for edge constraints
3  *
4  * Created: Sat Jul 12 14:48:02 2014
5  * Copyright 2014 Sebastian Reuter
6  * 2014 Tim Niemueller
7  ****************************************************************************/
8 
9 /* This program is free software; you can redistribute it and/or modify
10  * it under the terms of the GNU General Public License as published by
11  * the Free Software Foundation; either version 2 of the License, or
12  * (at your option) any later version.
13  *
14  * This program is distributed in the hope that it will be useful,
15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17  * GNU Library General Public License for more details.
18  *
19  * Read the full text in the LICENSE.GPL file in the doc directory.
20  */
21 
22 #include <navgraph/constraints/edge_constraint.h>
23 
24 namespace fawkes {
25 
26 /** @class NavGraphEdgeConstraint <navgraph/constraints/edge_constraint.h>
27  * Constraint that can be queried to check if an edge is blocked.
28  * @author Sebastian Reuter
29  * @author Tim Niemueller
30  *
31  * @fn bool NavGraphEdgeConstraint::blocks(const fawkes::NavGraphNode &from, const fawkes::NavGraphNode &to) throw() = 0
32  * Check if constraint blocks an edge.
33  * This method must be implemented by constraint classes. It is called
34  * to determine if an edge should be considered blocked and therefore
35  * cannot be expanded during path search.
36  *
37  * Note that the nodes may be passed in either ordering, therefore
38  * you should not rely on a particular order, not even for directed
39  * nodes!
40  *
41  * Further note that the method may not throw an exception. Handle
42  * this internally appropriately.
43  *
44  * @param from node from which the edge originates
45  * @param to node to which the edge leads
46  * @return true if the edge should be considered blocked, false otherwise
47  *
48  * @var std::string NavGraphEdgeConstraint::name_
49  * Name of constraint.
50  */
51 
52 /** Constructor.
53  * @param name name of edge constraint
54  */
56 {
57  name_ = name;
58 }
59 
60 /** Constructor.
61  * @param name name of edge constraint
62  */
64 {
65  name_ = name;
66 }
67 
68 /** Virtual empty destructor. */
70 {
71 }
72 
73 /** Get name of constraint.
74  * @return name of constraint
75  */
76 std::string
78 {
79  return name_;
80 }
81 
82 /** Perform compuations before graph search and to indicate re-planning.
83  * The compute method is called on all constraints just before a path
84  * search is performed and to check if re-planning should be tried.
85  *
86  * It can be used for example to cache results for the coming search
87  * run. The search guarantees that for each complete search run
88  * compute() is called once and only once and that no two search runs
89  * overlap, i.e., compute() will not be called while another search is
90  * still running.
91  *
92  * Constraints must indicate whether any change has occured during
93  * computation or since the last compute() call through the return
94  * value. This is used to determine if re-planning should be
95  * attempted.
96  *
97  * @return true if a change has occured during computation or since
98  * the last call, false otherwise
99  */
100 bool
102 {
103  return false;
104 }
105 
106 /** Check if constraint matches name.
107  * @param name name string to compare this constraints name to
108  * @return true if the given name is the same as this constraint's name,
109  * false otherwise
110  */
111 bool
112 NavGraphEdgeConstraint::operator==(const std::string &name) const
113 {
114  return name_ == name;
115 }
116 
117 } // end of namespace fawkes
Fawkes library namespace.
bool operator==(const std::string &name) const
Check if constraint matches name.
std::string name_
Name of constraint.
virtual ~NavGraphEdgeConstraint()
Virtual empty destructor.
std::string name()
Get name of constraint.
virtual bool compute(void)
Perform compuations before graph search and to indicate re-planning.
NavGraphEdgeConstraint(const std::string &name)
Constructor.