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diff --git a/src/quick/util/qdeclarativebind.cpp b/src/quick/util/qdeclarativebind.cpp
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+/****************************************************************************
+**
+** Copyright (C) 2011 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.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** GNU Lesser General Public License Usage
+** 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.
+**
+** 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.
+**
+** Other Usage
+** Alternatively, this file may be used in accordance with the terms and
+** conditions contained in a signed written agreement between you and Nokia.
+**
+**
+**
+**
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include "qdeclarativebind_p.h"
+
+#include <private/qdeclarativenullablevalue_p_p.h>
+#include <private/qdeclarativeproperty_p.h>
+#include <private/qdeclarativebinding_p.h>
+#include <private/qdeclarativeguard_p.h>
+
+#include <qdeclarativeengine.h>
+#include <qdeclarativecontext.h>
+#include <qdeclarativeproperty.h>
+#include <qdeclarativeinfo.h>
+
+#include <QtCore/qfile.h>
+#include <QtCore/qdebug.h>
+
+#include <private/qobject_p.h>
+
+QT_BEGIN_NAMESPACE
+
+class QDeclarativeBindPrivate : public QObjectPrivate
+{
+public:
+    QDeclarativeBindPrivate() : componentComplete(true), obj(0), prevBind(0) {}
+    ~QDeclarativeBindPrivate() { if (prevBind) prevBind->destroy(); }
+
+    QDeclarativeNullableValue<bool> when;
+    bool componentComplete;
+    QDeclarativeGuard<QObject> obj;
+    QString propName;
+    QDeclarativeNullableValue<QVariant> value;
+    QDeclarativeProperty prop;
+    QDeclarativeAbstractBinding *prevBind;
+};
+
+
+/*!
+    \qmlclass Binding QDeclarativeBind
+    \inqmlmodule QtQuick 2
+    \ingroup qml-working-with-data
+    \brief The Binding element allows arbitrary property bindings to be created.
+
+    \section1 Binding to an inaccessible property
+
+    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.
+
+    \section1 "Single-branch" conditional binding
+
+    In some circumstances you may want to control the value of a property
+    only when a certain condition is true (and relinquish control in all
+    other cirumstances). This often isn't possible to accomplish with a direct
+    binding, as you need to supply values for all possible branches.
+
+    \qml
+    // warning: "Unable to assign [undefined] to double value"
+    value: if (mouse.pressed) mouse.mouseX
+    \endqml
+
+    The above example will produce a warning whenever we release the mouse, as the value
+    of the binding is undefined when the mouse isn't pressed. We can use the Binding
+    element to rewrite the above code and avoid the warning.
+
+    \qml
+    Binding on value {
+        when: mouse.pressed
+        value: mouse.mouseX
+    }
+    \endqml
+
+    The Binding element will also restore any previously set direct bindings on
+    the property. In that sense, it functions much like a simplified State.
+
+    \qml
+    // this is equivilant to the above Binding
+    State {
+        name: "pressed"
+        when: mouse.pressed
+        PropertyChanges {
+            target: obj
+            value: mouse.mouseX
+        }
+    }
+    \endqml
+
+    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 QtQuick2::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
+
+    When the binding becomes inactive again, any direct bindings that were previously
+    set on the property will be restored.
+*/
+bool QDeclarativeBind::when() const
+{
+    Q_D(const QDeclarativeBind);
+    return d->when;
+}
+
+void QDeclarativeBind::setWhen(bool v)
+{
+    Q_D(QDeclarativeBind);
+    if (!d->when.isNull && d->when == v)
+        return;
+
+    d->when = v;
+    eval();
+}
+
+/*!
+    \qmlproperty Object QtQuick2::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);
+    if (d->obj && d->when.isValid() && d->when) {
+        /* if we switch the object at runtime, we need to restore the
+           previous binding on the old object before continuing */
+        d->when = false;
+        eval();
+        d->when = true;
+    }
+    d->obj = obj;
+    if (d->componentComplete)
+        d->prop = QDeclarativeProperty(d->obj, d->propName);
+    eval();
+}
+
+/*!
+    \qmlproperty string QtQuick2::Binding::property
+
+    The property to be updated.
+*/
+QString QDeclarativeBind::property() const
+{
+    Q_D(const QDeclarativeBind);
+    return d->propName;
+}
+
+void QDeclarativeBind::setProperty(const QString &p)
+{
+    Q_D(QDeclarativeBind);
+    if (!d->propName.isEmpty() && d->when.isValid() && d->when) {
+        /* if we switch the property name at runtime, we need to restore the
+           previous binding on the old object before continuing */
+        d->when = false;
+        eval();
+        d->when = true;
+    }
+    d->propName = p;
+    if (d->componentComplete)
+        d->prop = QDeclarativeProperty(d->obj, d->propName);
+    eval();
+}
+
+/*!
+    \qmlproperty any QtQuick2::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 = v;
+    eval();
+}
+
+void QDeclarativeBind::setTarget(const QDeclarativeProperty &p)
+{
+    Q_D(QDeclarativeBind);
+    d->prop = p;
+}
+
+void QDeclarativeBind::classBegin()
+{
+    Q_D(QDeclarativeBind);
+    d->componentComplete = false;
+}
+
+void QDeclarativeBind::componentComplete()
+{
+    Q_D(QDeclarativeBind);
+    d->componentComplete = true;
+    if (!d->prop.isValid())
+        d->prop = QDeclarativeProperty(d->obj, d->propName);
+    eval();
+}
+
+void QDeclarativeBind::eval()
+{
+    Q_D(QDeclarativeBind);
+    if (!d->prop.isValid() || d->value.isNull || !d->componentComplete)
+        return;
+
+    if (d->when.isValid()) {
+        if (!d->when) {
+            //restore any previous binding
+            if (d->prevBind) {
+                QDeclarativeAbstractBinding *tmp = d->prevBind;
+                d->prevBind = 0;
+                tmp = QDeclarativePropertyPrivate::setBinding(d->prop, tmp);
+                if (tmp) //should this ever be true?
+                    tmp->destroy();
+            }
+            return;
+        }
+
+        //save any set binding for restoration
+        QDeclarativeAbstractBinding *tmp;
+        tmp = QDeclarativePropertyPrivate::setBinding(d->prop, 0);
+        if (tmp && d->prevBind)
+            d->prevBind->destroy();
+        else if (!d->prevBind)
+            d->prevBind = tmp;
+    }
+
+    d->prop.write(d->value.value);
+}
+
+QT_END_NAMESPACE