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Diffstat (limited to 'src/declarative/util/qdeclarativebind.cpp')
-rw-r--r-- | src/declarative/util/qdeclarativebind.cpp | 203 |
1 files changed, 203 insertions, 0 deletions
diff --git a/src/declarative/util/qdeclarativebind.cpp b/src/declarative/util/qdeclarativebind.cpp new file mode 100644 index 0000000..e95a03e --- /dev/null +++ b/src/declarative/util/qdeclarativebind.cpp @@ -0,0 +1,203 @@ +/**************************************************************************** +** +** 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 "qdeclarativebind_p.h" + +#include "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(false), obj(0) {} + + bool when : 1; + bool componentComplete : 1; + QObject *obj; + QString prop; + QDeclarativeNullableValue<QVariant> value; +}; + + +/*! + \qmlclass Binding QDeclarativeBind + \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. + */ +/*! + \internal + \class QDeclarativeBind + \ingroup group_utility + \brief The QDeclarativeBind class allows arbitrary property bindings to be created. + + Simple bindings are usually earier to do in-place rather than creating a + QDeclarativeBind item. For that reason, QDeclarativeBind is usually used to transfer property information + from Qml to C++. + + \sa cppqml + */ +QDeclarativeBind::QDeclarativeBind(QObject *parent) + : QObject(*(new QDeclarativeBindPrivate), parent) +{ +} + +QDeclarativeBind::~QDeclarativeBind() +{ +} + +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::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 |