1
2
3
4
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
46
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
73
74
75
76
77
78
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
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
|
/****************************************************************************
**
** Copyright (C) 2015 The Qt Company Ltd.
** Contact: http://www.qt.io/licensing/
**
** This file is part of the QtQml module of the Qt Toolkit.
**
** $QT_BEGIN_LICENSE:LGPL21$
** Commercial License Usage
** Licensees holding valid commercial Qt licenses may use this file in
** accordance with the commercial license agreement provided with the
** Software or, alternatively, in accordance with the terms contained in
** a written agreement between you and The Qt Company. For licensing terms
** and conditions see http://www.qt.io/terms-conditions. For further
** information use the contact form at http://www.qt.io/contact-us.
**
** GNU Lesser General Public License Usage
** Alternatively, this file may be used under the terms of the GNU Lesser
** General Public License version 2.1 or version 3 as published by the Free
** Software Foundation and appearing in the file LICENSE.LGPLv21 and
** LICENSE.LGPLv3 included in the packaging of this file. Please review the
** following information to ensure the GNU Lesser General Public License
** requirements will be met: https://www.gnu.org/licenses/lgpl.html and
** http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
**
** As a special exception, The Qt Company gives you certain additional
** rights. These rights are described in The Qt Company LGPL Exception
** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
**
** $QT_END_LICENSE$
**
****************************************************************************/
#ifndef QQMLABSTRACTBINDING_P_H
#define QQMLABSTRACTBINDING_P_H
//
// W A R N I N G
// -------------
//
// This file is not part of the Qt API. It exists purely as an
// implementation detail. This header file may change from version to
// version without notice, or even be removed.
//
// We mean it.
//
#include <QtCore/qsharedpointer.h>
#include <private/qtqmlglobal_p.h>
#include <private/qqmlproperty_p.h>
#include <private/qpointervaluepair_p.h>
QT_BEGIN_NAMESPACE
class QQmlObjectCreator;
class Q_QML_PRIVATE_EXPORT QQmlAbstractBinding
{
public:
typedef QWeakPointer<QQmlAbstractBinding> Pointer;
enum BindingType { Binding = 0, ValueTypeProxy = 1 };
inline BindingType bindingType() const;
void destroy() {
removeFromObject();
clear();
delete this;
}
virtual QString expression() const;
// Should return the encoded property index for the binding. Should return this value
// even if the binding is not enabled or added to an object.
// Encoding is: coreIndex | (valueTypeIndex << 16)
virtual int targetPropertyIndex() const = 0;
// Should return the object for the binding. Should return this object even if the
// binding is not enabled or added to the object.
virtual QObject *targetObject() const = 0;
virtual void setEnabled(bool e, QQmlPropertyPrivate::WriteFlags f = QQmlPropertyPrivate::DontRemoveBinding) = 0;
void addToObject();
void removeFromObject();
static inline Pointer getPointer(QQmlAbstractBinding *p);
static void printBindingLoopError(QQmlProperty &prop);
inline QQmlAbstractBinding *nextBinding() const;
protected:
QQmlAbstractBinding(BindingType);
virtual ~QQmlAbstractBinding();
void clear();
private:
friend class QQmlData;
friend class QQmlValueTypeProxyBinding;
friend class QQmlObjectCreator;
Pointer weakPointer();
typedef QSharedPointer<QQmlAbstractBinding> SharedPointer;
// To save memory, we also store the rarely used weakPointer() instance in here
// We also use the flag bits:
// m_mePtr.flag1: added to object
QPointerValuePair<QQmlAbstractBinding*, SharedPointer> m_mePtr;
inline void setAddedToObject(bool v);
inline bool isAddedToObject() const;
inline void setNextBinding(QQmlAbstractBinding *);
// Pointer to the next binding in the linked list of bindings.
// Being a pointer, the address is always aligned to at least 4 bytes, which means the last two
// bits of the pointer are free to be used for something else. They are used to store the binding
// type. The binding type serves as an index into the static vTables array, which is used instead
// of a compiler-generated vTable. Instead of virtual functions, pointers to static functions in
// the vTables array are used for dispatching.
// This saves a compiler-generated pointer to a compiler-generated vTable, and thus reduces
// the binding object size by sizeof(void*).
qintptr m_nextBindingPtr;
};
QQmlAbstractBinding::Pointer
QQmlAbstractBinding::getPointer(QQmlAbstractBinding *p)
{
return p ? p->weakPointer() : Pointer();
}
void QQmlAbstractBinding::setAddedToObject(bool v)
{
m_mePtr.setFlagValue(v);
}
bool QQmlAbstractBinding::isAddedToObject() const
{
return m_mePtr.flag();
}
QQmlAbstractBinding *QQmlAbstractBinding::nextBinding() const
{
return (QQmlAbstractBinding *)(m_nextBindingPtr & ~0x3);
}
void QQmlAbstractBinding::setNextBinding(QQmlAbstractBinding *b)
{
m_nextBindingPtr = qintptr(b) | (m_nextBindingPtr & 0x3);
}
QQmlAbstractBinding::BindingType QQmlAbstractBinding::bindingType() const
{
return (BindingType)(m_nextBindingPtr & 0x3);
}
QT_END_NAMESPACE
#endif // QQMLABSTRACTBINDING_P_H
|
