diff -r b72c6db6890b -r 5dc02b23752f src/declarative/qml/qdeclarativebinding.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/declarative/qml/qdeclarativebinding.cpp	Tue Jul 06 15:10:48 2010 +0300
@@ -0,0 +1,477 @@
+/****************************************************************************
+**
+** 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/qdeclarativebinding_p.h"
+#include "private/qdeclarativebinding_p_p.h"
+
+#include "qdeclarative.h"
+#include "qdeclarativecontext.h"
+#include "qdeclarativeinfo.h"
+#include "private/qdeclarativecontext_p.h"
+#include "private/qdeclarativedata_p.h"
+#include "private/qdeclarativestringconverters_p.h"
+
+#include <QVariant>
+#include <QtCore/qdebug.h>
+
+QT_BEGIN_NAMESPACE
+
+QDeclarativeBindingData::QDeclarativeBindingData()
+: updating(false), enabled(false)
+{
+}
+
+QDeclarativeBindingData::~QDeclarativeBindingData()
+{
+    removeError();
+}
+
+void QDeclarativeBindingData::refresh()
+{
+    if (enabled && !updating && q) {
+        QDeclarativeBinding *b = static_cast<QDeclarativeBinding *>(QDeclarativeExpressionPrivate::get(q));
+        b->update();
+    }
+}
+
+QDeclarativeBindingPrivate::QDeclarativeBindingPrivate()
+: QDeclarativeExpressionPrivate(new QDeclarativeBindingData)
+{
+}
+
+QDeclarativeBinding::QDeclarativeBinding(void *data, QDeclarativeRefCount *rc, QObject *obj, 
+                                         QDeclarativeContextData *ctxt, const QString &url, int lineNumber, 
+                                         QObject *parent)
+: QDeclarativeExpression(ctxt, data, rc, obj, url, lineNumber, *new QDeclarativeBindingPrivate)
+{
+    setParent(parent);
+    setNotifyOnValueChanged(true);
+}
+
+QDeclarativeBinding::QDeclarativeBinding(const QString &str, QObject *obj, QDeclarativeContext *ctxt, 
+                                         QObject *parent)
+: QDeclarativeExpression(QDeclarativeContextData::get(ctxt), obj, str, *new QDeclarativeBindingPrivate)
+{
+    setParent(parent);
+    setNotifyOnValueChanged(true);
+}
+
+QDeclarativeBinding::QDeclarativeBinding(const QString &str, QObject *obj, QDeclarativeContextData *ctxt, 
+                                         QObject *parent)
+: QDeclarativeExpression(ctxt, obj, str, *new QDeclarativeBindingPrivate)
+{
+    setParent(parent);
+    setNotifyOnValueChanged(true);
+}
+
+QDeclarativeBinding::~QDeclarativeBinding()
+{
+}
+
+void QDeclarativeBinding::setTarget(const QDeclarativeProperty &prop)
+{
+    Q_D(QDeclarativeBinding);
+    d->bindingData()->property = prop;
+
+    update();
+}
+
+QDeclarativeProperty QDeclarativeBinding::property() const 
+{
+   Q_D(const QDeclarativeBinding);
+   return d->bindingData()->property; 
+}
+
+void QDeclarativeBinding::update(QDeclarativePropertyPrivate::WriteFlags flags)
+{
+    Q_D(QDeclarativeBinding);
+
+    QDeclarativeBindingData *data = d->bindingData();
+
+    if (!data->enabled || !data->context() || !data->context()->isValid())
+        return;
+
+    data->addref();
+
+    if (!data->updating) {
+        data->updating = true;
+
+        if (data->property.propertyType() == qMetaTypeId<QDeclarativeBinding *>()) {
+
+            int idx = data->property.index();
+            Q_ASSERT(idx != -1);
+
+
+            QDeclarativeBinding *t = this;
+            int status = -1;
+            void *a[] = { &t, 0, &status, &flags };
+            QMetaObject::metacall(data->property.object(),
+                                  QMetaObject::WriteProperty,
+                                  idx, a);
+
+        } else {
+            QDeclarativeEnginePrivate *ep = QDeclarativeEnginePrivate::get(data->context()->engine);
+
+            bool isUndefined = false;
+            QVariant value;
+
+            QScriptValue scriptValue = d->scriptValue(0, &isUndefined);
+            if (data->property.propertyTypeCategory() == QDeclarativeProperty::List) {
+                value = ep->scriptValueToVariant(scriptValue, qMetaTypeId<QList<QObject *> >());
+            } else if (scriptValue.isNull() && 
+                       data->property.propertyTypeCategory() == QDeclarativeProperty::Object) {
+                value = QVariant::fromValue((QObject *)0);
+            } else {
+                value = ep->scriptValueToVariant(scriptValue, data->property.propertyType());
+                if (value.userType() == QMetaType::QObjectStar && !qvariant_cast<QObject*>(value)) {
+                    // If the object is null, we extract the predicted type.  While this isn't
+                    // 100% reliable, in many cases it gives us better error messages if we
+                    // assign this null-object to an incompatible property
+                    int type = ep->objectClass->objectType(scriptValue);
+                    QObject *o = 0;
+                    value = QVariant(type, (void *)&o);
+                }
+            }
+
+
+            if (data->error.isValid()) {
+
+            } else if (isUndefined && data->property.isResettable()) {
+
+                data->property.reset();
+
+            } else if (isUndefined && data->property.propertyType() == qMetaTypeId<QVariant>()) {
+
+                QDeclarativePropertyPrivate::write(data->property, QVariant(), flags);
+
+            } else if (isUndefined) {
+
+                QUrl url = QUrl(data->url);
+                int line = data->line;
+                if (url.isEmpty()) url = QUrl(QLatin1String("<Unknown File>"));
+
+                data->error.setUrl(url);
+                data->error.setLine(line);
+                data->error.setColumn(-1);
+                data->error.setDescription(QLatin1String("Unable to assign [undefined] to ")
+                    + QLatin1String(QMetaType::typeName(data->property.propertyType()))
+                    + QLatin1String(" ") + data->property.name());
+
+            } else if (!scriptValue.isRegExp() && scriptValue.isFunction()) {
+
+                QUrl url = QUrl(data->url);
+                int line = data->line;
+                if (url.isEmpty()) url = QUrl(QLatin1String("<Unknown File>"));
+
+                data->error.setUrl(url);
+                data->error.setLine(line);
+                data->error.setColumn(-1);
+                data->error.setDescription(QLatin1String("Unable to assign a function to a property."));
+
+            } else if (data->property.object() &&
+                       !QDeclarativePropertyPrivate::write(data->property, value, flags)) {
+
+                QUrl url = QUrl(data->url);
+                int line = data->line;
+                if (url.isEmpty()) url = QUrl(QLatin1String("<Unknown File>"));
+
+                const char *valueType = 0;
+                if (value.userType() == QVariant::Invalid) valueType = "null";
+                else valueType = QMetaType::typeName(value.userType());
+
+                data->error.setUrl(url);
+                data->error.setLine(line);
+                data->error.setColumn(-1);
+                data->error.setDescription(QLatin1String("Unable to assign ") +
+                                           QLatin1String(valueType) +
+                                           QLatin1String(" to ") +
+                                           QLatin1String(QMetaType::typeName(data->property.propertyType())));
+            }
+
+            if (data->error.isValid()) {
+               if (!data->addError(ep)) ep->warning(this->error());
+            } else {
+                data->removeError();
+            }
+        }
+
+        data->updating = false;
+    } else {
+        qmlInfo(data->property.object()) << tr("Binding loop detected for property \"%1\"").arg(data->property.name());
+    }
+
+    data->release();
+}
+
+void QDeclarativeBindingPrivate::emitValueChanged()
+{
+    Q_Q(QDeclarativeBinding);
+    q->update();
+}
+
+void QDeclarativeBinding::setEnabled(bool e, QDeclarativePropertyPrivate::WriteFlags flags)
+{
+    Q_D(QDeclarativeBinding);
+    d->bindingData()->enabled = e;
+    setNotifyOnValueChanged(e);
+
+    QDeclarativeAbstractBinding::setEnabled(e, flags);
+
+    if (e) {
+        addToObject(d->bindingData()->property.object());
+        update(flags);
+    } else {
+        removeFromObject();
+    }
+}
+
+int QDeclarativeBinding::propertyIndex()
+{
+    Q_D(QDeclarativeBinding);
+    return QDeclarativePropertyPrivate::bindingIndex(d->bindingData()->property);
+}
+
+bool QDeclarativeBinding::enabled() const
+{
+    Q_D(const QDeclarativeBinding);
+
+    return d->bindingData()->enabled;
+}
+
+QString QDeclarativeBinding::expression() const
+{
+    return QDeclarativeExpression::expression();
+}
+
+QDeclarativeAbstractBinding::QDeclarativeAbstractBinding()
+: m_object(0), m_mePtr(0), m_prevBinding(0), m_nextBinding(0)
+{
+}
+
+QDeclarativeAbstractBinding::~QDeclarativeAbstractBinding()
+{
+    Q_ASSERT(m_prevBinding == 0);
+    Q_ASSERT(m_mePtr == 0);
+}
+
+void QDeclarativeAbstractBinding::destroy()
+{
+    removeFromObject();
+    clear();
+
+    delete this;
+}
+
+void QDeclarativeAbstractBinding::addToObject(QObject *object)
+{
+    Q_ASSERT(object);
+
+    if (m_object == object)
+        return;
+
+    int index = propertyIndex();
+
+    removeFromObject();
+
+    Q_ASSERT(!m_prevBinding);
+
+    m_object = object;
+    QDeclarativeData *data = QDeclarativeData::get(object, true);
+
+    if (index & 0xFF000000) {
+        // Value type
+
+        int coreIndex = index & 0xFFFFFF;
+
+        // Find the value type proxy (if there is one)
+        QDeclarativeValueTypeProxyBinding *proxy = 0;
+        if (data->hasBindingBit(coreIndex)) {
+            QDeclarativeAbstractBinding *b = data->bindings;
+            while (b && b->propertyIndex() != coreIndex)
+                b = b->m_nextBinding;
+            Q_ASSERT(b && b->bindingType() == QDeclarativeAbstractBinding::ValueTypeProxy);
+            proxy = static_cast<QDeclarativeValueTypeProxyBinding *>(b);
+        }
+
+        if (!proxy) 
+            proxy = new QDeclarativeValueTypeProxyBinding(object, coreIndex);
+        proxy->addToObject(object);
+
+        m_nextBinding = proxy->m_bindings;
+        if (m_nextBinding) m_nextBinding->m_prevBinding = &m_nextBinding;
+        m_prevBinding = &proxy->m_bindings;
+        proxy->m_bindings = this;
+
+    } else {
+        m_nextBinding = data->bindings;
+        if (m_nextBinding) m_nextBinding->m_prevBinding = &m_nextBinding;
+        m_prevBinding = &data->bindings;
+        data->bindings = this;
+
+        data->setBindingBit(m_object, index);
+    }
+}
+
+void QDeclarativeAbstractBinding::removeFromObject()
+{
+    if (m_prevBinding) {
+        int index = propertyIndex();
+
+        *m_prevBinding = m_nextBinding;
+        if (m_nextBinding) m_nextBinding->m_prevBinding = m_prevBinding;
+        m_prevBinding = 0;
+        m_nextBinding = 0;
+
+        if (index & 0xFF000000) {
+            // Value type - we don't remove the proxy from the object.  It will sit their happily
+            // doing nothing for ever more.
+        } else if (m_object) {
+            QDeclarativeData *data = QDeclarativeData::get(m_object, false);
+            if (data) data->clearBindingBit(index);
+        }
+
+        m_object = 0;
+    }
+}
+
+void QDeclarativeAbstractBinding::clear()
+{
+    if (m_mePtr) {
+        *m_mePtr = 0;
+        m_mePtr = 0;
+    }
+}
+
+QString QDeclarativeAbstractBinding::expression() const
+{
+    return QLatin1String("<Unknown>");
+}
+
+void QDeclarativeAbstractBinding::setEnabled(bool e, QDeclarativePropertyPrivate::WriteFlags)
+{
+    if (e) m_mePtr = 0;
+}
+
+QDeclarativeValueTypeProxyBinding::QDeclarativeValueTypeProxyBinding(QObject *o, int index)
+: m_object(o), m_index(index), m_bindings(0)
+{
+}
+
+QDeclarativeValueTypeProxyBinding::~QDeclarativeValueTypeProxyBinding()
+{
+    while (m_bindings) {
+        QDeclarativeAbstractBinding *binding = m_bindings;
+        binding->setEnabled(false, 0);
+        binding->destroy();
+    }
+}
+
+void QDeclarativeValueTypeProxyBinding::setEnabled(bool e, QDeclarativePropertyPrivate::WriteFlags flags)
+{
+    if (e) {
+        addToObject(m_object);
+
+        QDeclarativeAbstractBinding *bindings = m_bindings;
+        m_bindings = 0;
+        recursiveEnable(bindings, flags);
+    } else {
+        removeFromObject();
+
+        QDeclarativeAbstractBinding *bindings = m_bindings;
+        m_bindings = 0;
+        recursiveDisable(bindings);
+    }
+}
+
+void QDeclarativeValueTypeProxyBinding::recursiveEnable(QDeclarativeAbstractBinding *b, QDeclarativePropertyPrivate::WriteFlags flags)
+{
+    if (!b)
+        return;
+
+    QDeclarativeAbstractBinding *next = b->m_nextBinding;
+    b->m_prevBinding = 0;
+    b->m_nextBinding = 0;
+    Q_ASSERT(b->m_mePtr == 0);
+    b->m_mePtr = &b;
+
+    recursiveEnable(next, flags);
+
+    if (b)
+        b->setEnabled(true, flags);
+}
+
+void QDeclarativeValueTypeProxyBinding::recursiveDisable(QDeclarativeAbstractBinding *b)
+{
+    if (!b)
+        return;
+
+    recursiveDisable(b->m_nextBinding);
+
+    b->setEnabled(false, 0);
+
+    Q_ASSERT(b->m_prevBinding == 0);
+    Q_ASSERT(b->m_nextBinding == 0);
+    b->m_nextBinding = m_bindings;
+    if (b->m_nextBinding) b->m_nextBinding->m_prevBinding = &b->m_nextBinding;
+    b->m_prevBinding = &m_bindings;
+    m_bindings = b;
+}
+
+int QDeclarativeValueTypeProxyBinding::propertyIndex()
+{
+    return m_index;
+}
+
+void QDeclarativeValueTypeProxyBinding::update(QDeclarativePropertyPrivate::WriteFlags)
+{
+}
+
+QDeclarativeAbstractBinding *QDeclarativeValueTypeProxyBinding::binding(int propertyIndex)
+{
+    QDeclarativeAbstractBinding *binding = m_bindings;
+    
+    while (binding && binding->propertyIndex() != propertyIndex) 
+        binding = binding->m_nextBinding;
+
+    return binding;
+}
+
+QT_END_NAMESPACE