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/****************************************************************************
**
** Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies).
** All rights reserved.
** Contact: Nokia Corporation (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 Technology Preview License Agreement accompanying
** this package.
**
** 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 1.1, included in the file LGPL_EXCEPTION.txt in this package.
**
** If you have questions regarding the use of this file, please contact
** Nokia at qt-info@nokia.com.
**
**
**
**
**
**
**
**
** $QT_END_LICENSE$
**
****************************************************************************/
#include "private/qdeclarativebind_p.h"
#include "private/qdeclarativenullablevalue_p_p.h"
#include <qdeclarativeengine.h>
#include <qdeclarativecontext.h>
#include <qdeclarativeproperty.h>
#include <QtCore/qfile.h>
#include <QtCore/qdebug.h>
#include <QtScript/qscriptvalue.h>
#include <QtScript/qscriptcontext.h>
#include <QtScript/qscriptengine.h>
#include <private/qobject_p.h>
QT_BEGIN_NAMESPACE
class QDeclarativeBindPrivate : public QObjectPrivate
{
public:
QDeclarativeBindPrivate() : when(true), componentComplete(true), obj(0) {}
bool when : 1;
bool componentComplete : 1;
QObject *obj;
QString prop;
QDeclarativeNullableValue<QVariant> value;
};
/*!
\qmlclass Binding QDeclarativeBind
\ingroup qml-working-with-data
\since 4.7
\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 QtDeclarative
*/
QDeclarativeBind::QDeclarativeBind(QObject *parent)
: QObject(*(new QDeclarativeBindPrivate), parent)
{
}
QDeclarativeBind::~QDeclarativeBind()
{
}
/*!
\qmlproperty bool Binding::when
This property holds when the binding is active.
This should be set to an expression that evaluates to true when you want the binding to be active.
\code
Binding {
target: contactName; property: 'text'
value: name; when: list.ListView.isCurrentItem
}
\endcode
*/
bool QDeclarativeBind::when() const
{
Q_D(const QDeclarativeBind);
return d->when;
}
void QDeclarativeBind::setWhen(bool v)
{
Q_D(QDeclarativeBind);
d->when = v;
eval();
}
/*!
\qmlproperty Object Binding::target
The object to be updated.
*/
QObject *QDeclarativeBind::object()
{
Q_D(const QDeclarativeBind);
return d->obj;
}
void QDeclarativeBind::setObject(QObject *obj)
{
Q_D(QDeclarativeBind);
d->obj = obj;
eval();
}
/*!
\qmlproperty string Binding::property
The property to be updated.
*/
QString QDeclarativeBind::property() const
{
Q_D(const QDeclarativeBind);
return d->prop;
}
void QDeclarativeBind::setProperty(const QString &p)
{
Q_D(QDeclarativeBind);
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 QDeclarativeBind::value() const
{
Q_D(const QDeclarativeBind);
return d->value.value;
}
void QDeclarativeBind::setValue(const QVariant &v)
{
Q_D(QDeclarativeBind);
d->value.value = v;
d->value.isNull = false;
eval();
}
void QDeclarativeBind::classBegin()
{
Q_D(QDeclarativeBind);
d->componentComplete = false;
}
void QDeclarativeBind::componentComplete()
{
Q_D(QDeclarativeBind);
d->componentComplete = true;
eval();
}
void QDeclarativeBind::eval()
{
Q_D(QDeclarativeBind);
if (!d->obj || d->value.isNull || !d->when || !d->componentComplete)
return;
QDeclarativeProperty prop(d->obj, d->prop);
prop.write(d->value.value);
}
QT_END_NAMESPACE
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