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39 | |
40 | #ifndef QRECURSIONWATCHER_P_H |
41 | #define QRECURSIONWATCHER_P_H |
42 | |
43 | // |
44 | // W A R N I N G |
45 | // ------------- |
46 | // |
47 | // This file is not part of the Qt API. It exists purely as an |
48 | // implementation detail. This header file may change from version to |
49 | // version without notice, or even be removed. |
50 | // |
51 | // We mean it. |
52 | // |
53 | |
54 | #include <QtCore/qglobal.h> |
55 | |
56 | QT_BEGIN_NAMESPACE |
57 | |
58 | class QRecursionNode; |
59 | class QRecursionNode { |
60 | public: |
61 | inline QRecursionNode(); |
62 | bool *_r; |
63 | }; |
64 | |
65 | template<class T, QRecursionNode T::*Node> |
66 | class QRecursionWatcher { |
67 | public: |
68 | inline QRecursionWatcher(T *); |
69 | inline ~QRecursionWatcher(); |
70 | inline bool hasRecursed() const; |
71 | private: |
72 | T *_t; |
73 | bool _r; |
74 | }; |
75 | |
76 | QRecursionNode::QRecursionNode() |
77 | : _r(nullptr) |
78 | { |
79 | } |
80 | |
81 | template<class T, QRecursionNode T::*Node> |
82 | QRecursionWatcher<T, Node>::QRecursionWatcher(T *t) |
83 | : _t(t), _r(false) |
84 | { |
85 | if ((_t->*Node)._r) *(_t->*Node)._r = true; |
86 | (_t->*Node)._r = &_r; |
87 | } |
88 | |
89 | template<class T, QRecursionNode T::*Node> |
90 | QRecursionWatcher<T, Node>::~QRecursionWatcher() |
91 | { |
92 | if ((_t->*Node)._r == &_r) (_t->*Node)._r = nullptr; |
93 | } |
94 | |
95 | template<class T, QRecursionNode T::*Node> |
96 | bool QRecursionWatcher<T, Node>::hasRecursed() const |
97 | { |
98 | return _r; |
99 | } |
100 | |
101 | QT_END_NAMESPACE |
102 | |
103 | #endif // QRECURSIONWATCHER_P_H |
104 | |