1/*
2 Copyright 2009 Ingo Klöcker <kloecker@kde.org>
3
4 This library is free software; you can redistribute it and/or modify it
5 under the terms of the GNU Library General Public License as published by
6 the Free Software Foundation; either version 2 of the License, or (at your
7 option) any later version.
8
9 This library is distributed in the hope that it will be useful, but WITHOUT
10 ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 FITNESS FOR A PARTICULAR PURPOSE. See the GNU Library General Public
12 License for more details.
13
14 You should have received a copy of the GNU Library General Public License
15 along with this library; see the file COPYING.LIB. If not, write to the
16 Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
17 02110-1301, USA.
18*/
19
20#ifndef KCAL_COMPARISONVISITOR_H
21#define KCAL_COMPARISONVISITOR_H
22
23#include "kcal_export.h"
24#include "incidencebase.h"
25
26namespace KCal {
27
28/**
29 Helper for type correct comparison of incidences via pointers.
30
31 This class provides a way of correctly comparing one incidence to another,
32 given two IncidenceBase derived pointers. It effectively provides a virtual
33 comparison method which first type checks the two pointers to ensure they
34 reference the same incidence type, before performing the comparison.
35
36 Usage example:
37 @code
38 KCal::Incidence *incidence; // assume this is set somewhere else
39 KCal::Incidence *referenceIncidence; // assume this is set somewhere else
40
41 KCal::ComparisonVisitor visitor;
42
43 // compare
44 if ( visitor.compare( incidence, referenceIncidence ) ) {
45 // incidence and referenceIncidence point to identical incidences
46 }
47 @endcode
48
49 @author Ingo Klöcker <kloecker@kde.org>
50
51 @since 4.3
52 */
53class KCAL_DEPRECATED_EXPORT ComparisonVisitor : public IncidenceBase::Visitor
54{
55 public:
56 /**
57 Creates a visitor instance.
58 */
59 ComparisonVisitor();
60
61 /**
62 Destroys the instance.
63 */
64 virtual ~ComparisonVisitor();
65
66 /**
67 Compares the incidence referenced by @p incidence to the incidence
68 referenced by @p reference. Returns true, if the incidence referenced
69 by @p incidence is identical to the incidence referenced by @p reference.
70 Also returns true, if @p incidence and @p reference are both @c 0.
71
72 Basically it is a virtual equivalent of
73 @code
74 *incidence == *reference
75 @endcode
76
77 @param incidence pointer to the incidence to compare with the reference incidence
78 @param reference pointer to the reference incidence
79
80 @return @c true if the two incidences are identical or both @c 0
81 */
82 bool compare( IncidenceBase *incidence, const IncidenceBase *reference );
83
84 /**
85 Compares the event referenced by @p event to the incidence passed to
86 compare().
87
88 @return @c true if the event is identical to the reference incidence
89 */
90 virtual bool visit( Event *event );
91
92 /**
93 Compares the todo referenced by @p todo to the incidence passed to
94 compare().
95
96 @return @c true if the todo is identical to the reference incidence
97 */
98 virtual bool visit( Todo *todo );
99
100 /**
101 Compares the journal referenced by @p journal to the incidence passed to
102 compare().
103
104 @return @c true if the journal is identical to the reference incidence
105 */
106 virtual bool visit( Journal *journal );
107
108 /**
109 Compares the freebusy object referenced by @p freebusy to the incidence passed to
110 compare().
111
112 @return @c true if the freebusy object is identical to the reference incidence
113 */
114 virtual bool visit( FreeBusy *freebusy );
115
116 private:
117 //@cond PRIVATE
118 class Private;
119 Private *const d;
120 //@endcond
121
122 Q_DISABLE_COPY( ComparisonVisitor )
123};
124
125}
126
127#endif // KCAL_COMPARISONVISITOR_H
128