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
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
|
/****************************************************************************
**
** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies).
** Contact: Qt Software Information (qt-info@nokia.com)
**
** This file is part of the QtDeclarative module of the Qt Toolkit.
**
** $QT_BEGIN_LICENSE:LGPL$
** No Commercial Usage
** This file contains pre-release code and may not be distributed.
** You may use this file in accordance with the terms and conditions
** contained in the either Technology Preview License Agreement or the
** Beta Release License Agreement.
**
** 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 as published by the Free Software
** Foundation and appearing in the file LICENSE.LGPL included in the
** packaging of this file. Please review the following information to
** ensure the GNU Lesser General Public License version 2.1 requirements
** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
**
** In addition, as a special exception, Nokia gives you certain
** additional rights. These rights are described in the Nokia Qt LGPL
** Exception version 1.0, included in the file LGPL_EXCEPTION.txt in this
** package.
**
** GNU General Public License Usage
** Alternatively, this file may be used under the terms of the GNU
** General Public License version 3.0 as published by the Free Software
** Foundation and appearing in the file LICENSE.GPL included in the
** packaging of this file. Please review the following information to
** ensure the GNU General Public License version 3.0 requirements will be
** met: http://www.gnu.org/copyleft/gpl.html.
**
** If you are unsure which license is appropriate for your use, please
** contact the sales department at qt-sales@nokia.com.
** $QT_END_LICENSE$
**
****************************************************************************/
#include <QtDeclarative/qmlengine.h>
#include <QtDeclarative/qmlcontext.h>
#include <private/qobject_p.h>
#include <QtCore/qfile.h>
#include <QtCore/qdebug.h>
#include <QtScript/qscriptvalue.h>
#include <QtScript/qscriptcontext.h>
#include <QtScript/qscriptengine.h>
#include <private/qmlnullablevalue_p.h>
#include "qmlbind.h"
QT_BEGIN_NAMESPACE
class QmlBindPrivate : public QObjectPrivate
{
public:
QmlBindPrivate() : when(true), obj(0) {}
bool when;
QObject *obj;
QString prop;
QmlNullableValue<QVariant> value;
};
QML_DEFINE_TYPE(Qt,4,6,(QT_VERSION&0x00ff00)>>8,Binding,QmlBind)
/*!
\qmlclass Binding QmlBind
\brief The Binding element allows arbitrary property bindings to be created.
Sometimes it is necessary to bind to a property of an object that wasn't
directly instantiated by QML - generally a property of a class exported
to QML by C++. In these cases, regular property binding doesn't work. Binding
allows you to bind any value to any property.
For example, imagine a C++ application that maps an "app.enteredText"
property into QML. You could use Binding to update the enteredText property
like this.
\code
TextEdit { id: myTextField; text: "Please type here..." }
Binding { target: app; property: "enteredText"; value: myTextField.text }
\endcode
Whenever the text in the TextEdit is updated, the C++ property will be
updated also.
If the binding target or binding property is changed, the bound value is
immediately pushed onto the new target.
\sa {qmlforcpp}{Qt Declarative Markup Language For C++ Programmers}
*/
/*!
\internal
\class QmlBind
\ingroup group_utility
\brief The QmlBind class allows arbitrary property bindings to be created.
Simple bindings are usually earier to do in-place rather than creating a
QmlBind item. For that reason, QmlBind is usually used to transfer property information
from Qml to C++.
\sa cppqml
*/
QmlBind::QmlBind(QObject *parent)
: QObject(*(new QmlBindPrivate), parent)
{
}
QmlBind::~QmlBind()
{
}
bool QmlBind::when() const
{
Q_D(const QmlBind);
return d->when;
}
void QmlBind::setWhen(bool v)
{
Q_D(QmlBind);
d->when = v;
eval();
}
/*!
\qmlproperty Object Binding::target
The object to be updated.
*/
QObject *QmlBind::object()
{
Q_D(const QmlBind);
return d->obj;
}
void QmlBind::setObject(QObject *obj)
{
Q_D(QmlBind);
d->obj = obj;
eval();
}
/*!
\qmlproperty string Binding::property
The property to be updated.
*/
QString QmlBind::property() const
{
Q_D(const QmlBind);
return d->prop;
}
void QmlBind::setProperty(const QString &p)
{
Q_D(QmlBind);
d->prop = p;
eval();
}
/*!
\qmlproperty any Binding::value
The value to be set on the target object and property. This can be a
constant (which isn't very useful), or a bound expression.
*/
QVariant QmlBind::value() const
{
Q_D(const QmlBind);
return d->value.value;
}
void QmlBind::setValue(const QVariant &v)
{
Q_D(QmlBind);
d->value.value = v;
d->value.isNull = false;
eval();
}
void QmlBind::eval()
{
Q_D(QmlBind);
if (!d->obj || d->value.isNull || !d->when)
return;
QmlMetaProperty prop(d->obj, d->prop);
prop.write(d->value.value);
}
QT_END_NAMESPACE
|
