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39
40#ifndef QQMLABSTRACTBINDING_P_H
41#define QQMLABSTRACTBINDING_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/qsharedpointer.h>
55#include <QtCore/qshareddata.h>
56#include <private/qtqmlglobal_p.h>
57#include <private/qqmlproperty_p.h>
58
59QT_BEGIN_NAMESPACE
60
61class QQmlObjectCreator;
62
63class Q_QML_PRIVATE_EXPORT QQmlAbstractBinding
64{
65protected:
66 QQmlAbstractBinding();
67public:
68 virtual ~QQmlAbstractBinding();
69
70 typedef QExplicitlySharedDataPointer<QQmlAbstractBinding> Ptr;
71
72 virtual QString expression() const;
73
74 virtual bool isValueTypeProxy() const;
75
76 // Should return the encoded property index for the binding. Should return this value
77 // even if the binding is not enabled or added to an object.
78 // Encoding is: coreIndex | (valueTypeIndex << 16)
79 QQmlPropertyIndex targetPropertyIndex() const { return m_targetIndex; }
80
81 // Should return the object for the binding. Should return this object even if the
82 // binding is not enabled or added to the object.
83 QObject *targetObject() const { return m_target.data(); }
84
85 virtual void setEnabled(bool e, QQmlPropertyData::WriteFlags f = QQmlPropertyData::DontRemoveBinding) = 0;
86
87 void addToObject();
88 void removeFromObject();
89
90 static void printBindingLoopError(QQmlProperty &prop);
91
92 inline QQmlAbstractBinding *nextBinding() const;
93
94 inline bool canUseAccessor() const
95 { return m_nextBinding.flag2(); }
96
97 struct RefCount {
98 RefCount() {}
99 int refCount = 0;
100 void ref() { ++refCount; }
101 int deref() { return --refCount; }
102 operator int() const { return refCount; }
103 };
104 RefCount ref;
105
106protected:
107 friend class QQmlData;
108 friend class QQmlValueTypeProxyBinding;
109 friend class QQmlObjectCreator;
110
111 inline void setAddedToObject(bool v);
112 inline bool isAddedToObject() const;
113
114 inline void setNextBinding(QQmlAbstractBinding *);
115
116 QQmlPropertyIndex m_targetIndex;
117
118 // Pointer is the target object to which the binding binds
119 // flag1 is the updating flag
120 // flag2 is the enabled flag
121 QFlagPointer<QObject> m_target;
122
123 // Pointer to the next binding in the linked list of bindings.
124 // flag1 is used for addedToObject
125 // flag2 indicates if an accessor is can be used (i.e. there is no interceptor on the target)
126 QFlagPointer<QQmlAbstractBinding> m_nextBinding;
127};
128
129void QQmlAbstractBinding::setAddedToObject(bool v)
130{
131 m_nextBinding.setFlagValue(v);
132}
133
134bool QQmlAbstractBinding::isAddedToObject() const
135{
136 return m_nextBinding.flag();
137}
138
139QQmlAbstractBinding *QQmlAbstractBinding::nextBinding() const
140{
141 return m_nextBinding.data();
142}
143
144void QQmlAbstractBinding::setNextBinding(QQmlAbstractBinding *b)
145{
146 if (b)
147 b->ref.ref();
148 if (m_nextBinding.data() && !m_nextBinding->ref.deref())
149 delete m_nextBinding.data();
150 m_nextBinding = b;
151}
152
153QT_END_NAMESPACE
154
155#endif // QQMLABSTRACTBINDING_P_H
156