/****************************************************************************

**

** 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.

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** $QT_END_LICENSE$

**

****************************************************************************/

#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

void QDeclarativeBindingPrivate::refresh()

{

    Q_Q(QDeclarativeBinding);

    q->update();

}

QDeclarativeBindingPrivate::QDeclarativeBindingPrivate()

: updating(false), enabled(false), deleted(0)

{

}

QDeclarativeBindingPrivate::~QDeclarativeBindingPrivate()

{

    if (deleted) *deleted = true;

}

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->property = prop;

    update();

}

QDeclarativeProperty QDeclarativeBinding::property() const 

{

   Q_D(const QDeclarativeBinding);

   return d->property; 

}

void QDeclarativeBinding::update(QDeclarativePropertyPrivate::WriteFlags flags)

{

    Q_D(QDeclarativeBinding);

    if (!d->enabled || !d->context() || !d->context()->isValid()) 

        return;

    if (!d->updating) {

        d->updating = true;

        bool wasDeleted = false;

        d->deleted = &wasDeleted;

        if (d->property.propertyType() == qMetaTypeId<QDeclarativeBinding *>()) {

            int idx = d->property.index();

            Q_ASSERT(idx != -1);

            QDeclarativeBinding *t = this;

            int status = -1;

            void *a[] = { &t, 0, &status, &flags };

            QMetaObject::metacall(d->property.object(),

                                  QMetaObject::WriteProperty,

                                  idx, a);

            if (wasDeleted)

                return;

        } else {

            QDeclarativeEnginePrivate *ep = QDeclarativeEnginePrivate::get(d->context()->engine);

            bool isUndefined = false;

            QVariant value;

            QScriptValue scriptValue = d->scriptValue(0, &isUndefined);

            if (wasDeleted)

                return;

            if (d->property.propertyTypeCategory() == QDeclarativeProperty::List) {

                value = ep->scriptValueToVariant(scriptValue, qMetaTypeId<QList<QObject *> >());

            } else if (scriptValue.isNull() && 

                       d->property.propertyTypeCategory() == QDeclarativeProperty::Object) {

                value = QVariant::fromValue((QObject *)0);

            } else {

                value = ep->scriptValueToVariant(scriptValue, d->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 (d->error.isValid()) {

            } else if (isUndefined && d->property.isResettable()) {

                d->property.reset();

            } else if (isUndefined && d->property.propertyType() == qMetaTypeId<QVariant>()) {

                QDeclarativePropertyPrivate::write(d->property, QVariant(), flags);

            } else if (isUndefined) {

                QUrl url = QUrl(d->url);

                int line = d->line;

                if (url.isEmpty()) url = QUrl(QLatin1String("<Unknown File>"));

                d->error.setUrl(url);

                d->error.setLine(line);

                d->error.setColumn(-1);

                d->error.setDescription(QLatin1String("Unable to assign [undefined] to ") +

                                        QLatin1String(QMetaType::typeName(d->property.propertyType())) +

                                        QLatin1String(" ") + d->property.name());

            } else if (!scriptValue.isRegExp() && scriptValue.isFunction()) {

                QUrl url = QUrl(d->url);

                int line = d->line;

                if (url.isEmpty()) url = QUrl(QLatin1String("<Unknown File>"));

                d->error.setUrl(url);

                d->error.setLine(line);

                d->error.setColumn(-1);

                d->error.setDescription(QLatin1String("Unable to assign a function to a property."));

            } else if (d->property.object() &&

                       !QDeclarativePropertyPrivate::write(d->property, value, flags)) {

                if (wasDeleted)

                    return;

                QUrl url = QUrl(d->url);

                int line = d->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());

                d->error.setUrl(url);

                d->error.setLine(line);

                d->error.setColumn(-1);

                d->error.setDescription(QLatin1String("Unable to assign ") +

                                        QLatin1String(valueType) +

                                        QLatin1String(" to ") +

                                        QLatin1String(QMetaType::typeName(d->property.propertyType())));

            }

            if (wasDeleted)

                return;

            if (d->error.isValid()) {

               if (!d->addError(ep)) ep->warning(this->error());

            } else {

                d->removeError();

            }

        }

        d->updating = false;

        d->deleted = 0;

    } else {

        qmlInfo(d->property.object()) << tr("Binding loop detected for property \"%1\"").arg(d->property.name());

    }

}

void QDeclarativeBindingPrivate::emitValueChanged()

{

    Q_Q(QDeclarativeBinding);

    q->update();

}

void QDeclarativeBinding::setEnabled(bool e, QDeclarativePropertyPrivate::WriteFlags flags)

{

    Q_D(QDeclarativeBinding);

    d->enabled = e;

    setNotifyOnValueChanged(e);

    QDeclarativeAbstractBinding::setEnabled(e, flags);

    if (e) {

        addToObject(d->property.object());

        update(flags);

    } else {

        removeFromObject();

    }

}

int QDeclarativeBinding::propertyIndex()

{

    Q_D(QDeclarativeBinding);

    return QDeclarativePropertyPrivate::bindingIndex(d->property);

}

bool QDeclarativeBinding::enabled() const

{

    Q_D(const QDeclarativeBinding);

    return d->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