qdeclarativepropertychanges.cpp

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#include "private/qdeclarativepropertychanges_p.h"

#include "private/qdeclarativeopenmetaobject_p.h"
#include "private/qdeclarativerewrite_p.h"
#include "private/qdeclarativeengine_p.h"
#include "private/qdeclarativecompiler_p.h"

#include <qdeclarativeinfo.h>
#include <qdeclarativecustomparser_p.h>
#include <qdeclarativeparser_p.h>
#include <qdeclarativeexpression.h>
#include <qdeclarativebinding_p.h>
#include <qdeclarativecontext.h>
#include <qdeclarativeguard_p.h>
#include <qdeclarativeproperty_p.h>
#include <qdeclarativecontext_p.h>
#include <qdeclarativestate_p_p.h>

#include <QtCore/qdebug.h>

#include <private/qobject_p.h>

QT_BEGIN_NAMESPACE

class QDeclarativeReplaceSignalHandler : public QDeclarativeActionEvent
{
public:
    QDeclarativeReplaceSignalHandler() : expression(0), reverseExpression(0),
                                rewindExpression(0), ownedExpression(0) {}
    ~QDeclarativeReplaceSignalHandler() {
        delete ownedExpression;
    }

    virtual QString typeName() const { return QLatin1String("ReplaceSignalHandler"); }

    QDeclarativeProperty property;
    QDeclarativeExpression *expression;
    QDeclarativeExpression *reverseExpression;
    QDeclarativeExpression *rewindExpression;
    QDeclarativeGuard<QDeclarativeExpression> ownedExpression;

    virtual void execute(Reason) {
        ownedExpression = QDeclarativePropertyPrivate::setSignalExpression(property, expression);
        if (ownedExpression == expression)
            ownedExpression = 0;
    }

    virtual bool isReversable() { return true; }
    virtual void reverse(Reason) {
        ownedExpression = QDeclarativePropertyPrivate::setSignalExpression(property, reverseExpression);
        if (ownedExpression == reverseExpression)
            ownedExpression = 0;
    }

    virtual void saveOriginals() {
        saveCurrentValues();
        reverseExpression = rewindExpression;
    }

    virtual bool needsCopy() { return true; }
    virtual void copyOriginals(QDeclarativeActionEvent *other)
    {
        QDeclarativeReplaceSignalHandler *rsh = static_cast<QDeclarativeReplaceSignalHandler*>(other);
        saveCurrentValues();
        if (rsh == this)
            return;
        reverseExpression = rsh->reverseExpression;
        if (rsh->ownedExpression == reverseExpression) {
            ownedExpression = rsh->ownedExpression;
            rsh->ownedExpression = 0;
        }
    }

    virtual void rewind() {
        ownedExpression = QDeclarativePropertyPrivate::setSignalExpression(property, rewindExpression);
        if (ownedExpression == rewindExpression)
            ownedExpression = 0;
    }
    virtual void saveCurrentValues() {
        rewindExpression = QDeclarativePropertyPrivate::signalExpression(property);
    }

    virtual bool override(QDeclarativeActionEvent*other) {
        if (other == this)
            return true;
        if (other->typeName() != typeName())
            return false;
        if (static_cast<QDeclarativeReplaceSignalHandler*>(other)->property == property)
            return true;
        return false;
    }
};


class QDeclarativePropertyChangesPrivate : public QDeclarativeStateOperationPrivate
{
    Q_DECLARE_PUBLIC(QDeclarativePropertyChanges)
public:
    QDeclarativePropertyChangesPrivate() : decoded(true), restore(true),
                                isExplicit(false) {}

    QDeclarativeGuard<QObject> object;
    QByteArray data;

    bool decoded : 1;
    bool restore : 1;
    bool isExplicit : 1;

    void decode();

    class ExpressionChange {
    public:
        ExpressionChange(const QString &_name,
                         QDeclarativeBinding::Identifier _id,
                         QDeclarativeExpression *_expr)
            : name(_name), id(_id), expression(_expr) {}
        QString name;
        QDeclarativeBinding::Identifier id;
        QDeclarativeExpression *expression;
    };

    QList<QPair<QString, QVariant> > properties;
    QList<ExpressionChange> expressions;
    QList<QDeclarativeReplaceSignalHandler*> signalReplacements;

    QDeclarativeProperty property(const QString &);
};

void
QDeclarativePropertyChangesParser::compileList(QList<QPair<QByteArray, QVariant> > &list,
                                     const QByteArray &pre,
                                     const QDeclarativeCustomParserProperty &prop)
{
    QByteArray propName = pre + prop.name();

    QList<QVariant> values = prop.assignedValues();
    for (int ii = 0; ii < values.count(); ++ii) {
        const QVariant &value = values.at(ii);

        if (value.userType() == qMetaTypeId<QDeclarativeCustomParserNode>()) {
            error(qvariant_cast<QDeclarativeCustomParserNode>(value),
                  QDeclarativePropertyChanges::tr("PropertyChanges does not support creating state-specific objects."));
            continue;
        } else if(value.userType() == qMetaTypeId<QDeclarativeCustomParserProperty>()) {

            QDeclarativeCustomParserProperty prop =
                qvariant_cast<QDeclarativeCustomParserProperty>(value);
            QByteArray pre = propName + '.';
            compileList(list, pre, prop);

        } else {
            list << qMakePair(propName, value);
        }
    }
}

QByteArray
QDeclarativePropertyChangesParser::compile(const QList<QDeclarativeCustomParserProperty> &props)
{
    QList<QPair<QByteArray, QVariant> > data;
    for(int ii = 0; ii < props.count(); ++ii)
        compileList(data, QByteArray(), props.at(ii));

    QByteArray rv;
    QDataStream ds(&rv, QIODevice::WriteOnly);

    ds << data.count();
    for(int ii = 0; ii < data.count(); ++ii) {
        QDeclarativeParser::Variant v = qvariant_cast<QDeclarativeParser::Variant>(data.at(ii).second);
        QVariant var;
        bool isScript = v.isScript();
        QDeclarativeBinding::Identifier id = 0;
        switch(v.type()) {
        case QDeclarativeParser::Variant::Boolean:
            var = QVariant(v.asBoolean());
            break;
        case QDeclarativeParser::Variant::Number:
            var = QVariant(v.asNumber());
            break;
        case QDeclarativeParser::Variant::String:
            var = QVariant(v.asString());
            break;
        case QDeclarativeParser::Variant::Invalid:
        case QDeclarativeParser::Variant::Script:
            var = QVariant(v.asScript());
            {
                // Pre-rewrite the expression
                QString expression = v.asScript();
                id = rewriteBinding(expression, data.at(ii).first); //### recreates the AST, which is slow
            }
            break;
        }

        ds << QString::fromUtf8(data.at(ii).first) << isScript << var;
        if (isScript)
            ds << id;
    }

    return rv;
}

void QDeclarativePropertyChangesPrivate::decode()
{
    Q_Q(QDeclarativePropertyChanges);
    if (decoded)
        return;

    QDataStream ds(&data, QIODevice::ReadOnly);

    int count;
    ds >> count;
    for (int ii = 0; ii < count; ++ii) {
        QString name;
        bool isScript;
        QVariant data;
        QDeclarativeBinding::Identifier id = QDeclarativeBinding::Invalid;
        ds >> name;
        ds >> isScript;
        ds >> data;
        if (isScript)
            ds >> id;

        QDeclarativeProperty prop = property(name);      //### better way to check for signal property?
        if (prop.type() & QDeclarativeProperty::SignalProperty) {
            QDeclarativeExpression *expression = new QDeclarativeExpression(qmlContext(q), object, data.toString());
            QDeclarativeData *ddata = QDeclarativeData::get(q);
            if (ddata && ddata->outerContext && !ddata->outerContext->url.isEmpty())
                expression->setSourceLocation(ddata->outerContext->url.toString(), ddata->lineNumber);
            QDeclarativeReplaceSignalHandler *handler = new QDeclarativeReplaceSignalHandler;
            handler->property = prop;
            handler->expression = expression;
            signalReplacements << handler;
        } else if (isScript) {
            QDeclarativeExpression *expression = new QDeclarativeExpression(qmlContext(q), object, data.toString());
            QDeclarativeData *ddata = QDeclarativeData::get(q);
            if (ddata && ddata->outerContext && !ddata->outerContext->url.isEmpty())
                expression->setSourceLocation(ddata->outerContext->url.toString(), ddata->lineNumber);
            expressions << ExpressionChange(name, id, expression);
        } else {
            properties << qMakePair(name, data);
        }
    }

    decoded = true;
    data.clear();
}

void QDeclarativePropertyChangesParser::setCustomData(QObject *object,
                                            const QByteArray &data)
{
    QDeclarativePropertyChangesPrivate *p =
        static_cast<QDeclarativePropertyChangesPrivate *>(QObjectPrivate::get(object));
    p->data = data;
    p->decoded = false;
}

QDeclarativePropertyChanges::QDeclarativePropertyChanges()
: QDeclarativeStateOperation(*(new QDeclarativePropertyChangesPrivate))
{
}

QDeclarativePropertyChanges::~QDeclarativePropertyChanges()
{
    Q_D(QDeclarativePropertyChanges);
    for(int ii = 0; ii < d->expressions.count(); ++ii)
        delete d->expressions.at(ii).expression;
    for(int ii = 0; ii < d->signalReplacements.count(); ++ii)
        delete d->signalReplacements.at(ii);
}

QObject *QDeclarativePropertyChanges::object() const
{
    Q_D(const QDeclarativePropertyChanges);
    return d->object;
}

void QDeclarativePropertyChanges::setObject(QObject *o)
{
    Q_D(QDeclarativePropertyChanges);
    d->object = o;
}

bool QDeclarativePropertyChanges::restoreEntryValues() const
{
    Q_D(const QDeclarativePropertyChanges);
    return d->restore;
}

void QDeclarativePropertyChanges::setRestoreEntryValues(bool v)
{
    Q_D(QDeclarativePropertyChanges);
    d->restore = v;
}

QDeclarativeProperty
QDeclarativePropertyChangesPrivate::property(const QString &property)
{
    Q_Q(QDeclarativePropertyChanges);
    QDeclarativeProperty prop(object, property, qmlContext(q));
    if (!prop.isValid()) {
        qmlInfo(q) << QDeclarativePropertyChanges::tr("Cannot assign to non-existent property \"%1\"").arg(property);
        return QDeclarativeProperty();
    } else if (!(prop.type() & QDeclarativeProperty::SignalProperty) && !prop.isWritable()) {
        qmlInfo(q) << QDeclarativePropertyChanges::tr("Cannot assign to read-only property \"%1\"").arg(property);
        return QDeclarativeProperty();
    }
    return prop;
}

QDeclarativePropertyChanges::ActionList QDeclarativePropertyChanges::actions()
{
    Q_D(QDeclarativePropertyChanges);

    d->decode();

    ActionList list;

    for (int ii = 0; ii < d->properties.count(); ++ii) {

        QDeclarativeAction a(d->object, d->properties.at(ii).first,
                 qmlContext(this), d->properties.at(ii).second);

        if (a.property.isValid()) {
            a.restore = restoreEntryValues();
            list << a;
        }
    }

    for (int ii = 0; ii < d->signalReplacements.count(); ++ii) {

        QDeclarativeReplaceSignalHandler *handler = d->signalReplacements.at(ii);

        if (handler->property.isValid()) {
            QDeclarativeAction a;
            a.event = handler;
            list << a;
        }
    }

    for (int ii = 0; ii < d->expressions.count(); ++ii) {

        const QString &property = d->expressions.at(ii).name;
        QDeclarativeProperty prop = d->property(property);

        if (prop.isValid()) {
            QDeclarativeAction a;
            a.restore = restoreEntryValues();
            a.property = prop;
            a.fromValue = a.property.read();
            a.specifiedObject = d->object;
            a.specifiedProperty = property;

            if (d->isExplicit) {
                a.toValue = d->expressions.at(ii).expression->evaluate();
            } else {
                QDeclarativeExpression *e = d->expressions.at(ii).expression;

                QDeclarativeBinding::Identifier id = d->expressions.at(ii).id;
                QDeclarativeBinding *newBinding = id != QDeclarativeBinding::Invalid ? QDeclarativeBinding::createBinding(id, object(), qmlContext(this), e->sourceFile(), e->lineNumber()) : 0;
                if (!newBinding) {
                    newBinding = new QDeclarativeBinding(e->expression(), object(), qmlContext(this));
                    newBinding->setSourceLocation(e->sourceFile(), e->lineNumber());
                }
                newBinding->setTarget(prop);
                a.toBinding = newBinding;
                a.deletableToBinding = true;
            }

            list << a;
        }
    }

    return list;
}

bool QDeclarativePropertyChanges::isExplicit() const
{
    Q_D(const QDeclarativePropertyChanges);
    return d->isExplicit;
}

void QDeclarativePropertyChanges::setIsExplicit(bool e)
{
    Q_D(QDeclarativePropertyChanges);
    d->isExplicit = e;
}

bool QDeclarativePropertyChanges::containsValue(const QString &name) const
{
    Q_D(const QDeclarativePropertyChanges);
    typedef QPair<QString, QVariant> PropertyEntry;

    QListIterator<PropertyEntry> propertyIterator(d->properties);
    while (propertyIterator.hasNext()) {
        const PropertyEntry &entry = propertyIterator.next();
        if (entry.first == name) {
            return true;
        }
    }

    return false;
}

bool QDeclarativePropertyChanges::containsExpression(const QString &name) const
{
    Q_D(const QDeclarativePropertyChanges);
    typedef QDeclarativePropertyChangesPrivate::ExpressionChange ExpressionEntry;

    QListIterator<ExpressionEntry> expressionIterator(d->expressions);
    while (expressionIterator.hasNext()) {
        const ExpressionEntry &entry = expressionIterator.next();
        if (entry.name == name) {
            return true;
        }
    }

    return false;
}

bool QDeclarativePropertyChanges::containsProperty(const QString &name) const
{
    return containsValue(name) || containsExpression(name);
}

void QDeclarativePropertyChanges::changeValue(const QString &name, const QVariant &value)
{
    Q_D(QDeclarativePropertyChanges);
    typedef QPair<QString, QVariant> PropertyEntry;
    typedef QDeclarativePropertyChangesPrivate::ExpressionChange ExpressionEntry;

    QMutableListIterator<ExpressionEntry> expressionIterator(d->expressions);
    while (expressionIterator.hasNext()) {
        const ExpressionEntry &entry = expressionIterator.next();
        if (entry.name == name) {
            expressionIterator.remove();
            if (state() && state()->isStateActive()) {
                QDeclarativeAbstractBinding *oldBinding = QDeclarativePropertyPrivate::binding(d->property(name));
                if (oldBinding) {
                    QDeclarativePropertyPrivate::setBinding(d->property(name), 0);
                    oldBinding->destroy();
                }
                d->property(name).write(value);
            }

            d->properties.append(PropertyEntry(name, value));
            return;
        }
    }

    QMutableListIterator<PropertyEntry> propertyIterator(d->properties);
    while (propertyIterator.hasNext()) {
        PropertyEntry &entry = propertyIterator.next();
        if (entry.first == name) {
            entry.second = value;
            if (state() && state()->isStateActive())
                d->property(name).write(value);
            return;
        }
    }

    QDeclarativeAction action;
    action.restore = restoreEntryValues();
    action.property = d->property(name);
    action.fromValue = action.property.read();
    action.specifiedObject = object();
    action.specifiedProperty = name;
    action.toValue = value;

    propertyIterator.insert(PropertyEntry(name, value));
    if (state() && state()->isStateActive()) {
        state()->addEntryToRevertList(action);
        QDeclarativeAbstractBinding *oldBinding = QDeclarativePropertyPrivate::binding(action.property);
        if (oldBinding)
            oldBinding->setEnabled(false, QDeclarativePropertyPrivate::DontRemoveBinding | QDeclarativePropertyPrivate::BypassInterceptor);
        d->property(name).write(value);
    }
}

void QDeclarativePropertyChanges::changeExpression(const QString &name, const QString &expression)
{
    Q_D(QDeclarativePropertyChanges);
    typedef QPair<QString, QVariant> PropertyEntry;
    typedef QDeclarativePropertyChangesPrivate::ExpressionChange ExpressionEntry;

    bool hadValue = false;

    QMutableListIterator<PropertyEntry> propertyIterator(d->properties);
    while (propertyIterator.hasNext()) {
        PropertyEntry &entry = propertyIterator.next();
        if (entry.first == name) {
            propertyIterator.remove();
            hadValue = true;
            break;
        }
    }

    QMutableListIterator<ExpressionEntry> expressionIterator(d->expressions);
    while (expressionIterator.hasNext()) {
        const ExpressionEntry &entry = expressionIterator.next();
        if (entry.name == name) {
            entry.expression->setExpression(expression);
            if (state() && state()->isStateActive()) {
                QDeclarativeAbstractBinding *oldBinding = QDeclarativePropertyPrivate::binding(d->property(name));
                if (oldBinding) {
                       QDeclarativePropertyPrivate::setBinding(d->property(name), 0);
                       oldBinding->destroy();
                }

                QDeclarativeBinding *newBinding = new QDeclarativeBinding(expression, object(), qmlContext(this));
                newBinding->setTarget(d->property(name));
                QDeclarativePropertyPrivate::setBinding(d->property(name), newBinding, QDeclarativePropertyPrivate::DontRemoveBinding | QDeclarativePropertyPrivate::BypassInterceptor);
            }
            return;
        }
    }

    QDeclarativeExpression *newExpression = new QDeclarativeExpression(qmlContext(this), d->object, expression);
    expressionIterator.insert(ExpressionEntry(name, QDeclarativeBinding::Invalid, newExpression));

    if (state() && state()->isStateActive()) {
        if (hadValue) {
            QDeclarativeAbstractBinding *oldBinding = QDeclarativePropertyPrivate::binding(d->property(name));
            if (oldBinding) {
                oldBinding->setEnabled(false, QDeclarativePropertyPrivate::DontRemoveBinding | QDeclarativePropertyPrivate::BypassInterceptor);
                state()->changeBindingInRevertList(object(), name, oldBinding);
            }

            QDeclarativeBinding *newBinding = new QDeclarativeBinding(expression, object(), qmlContext(this));
            newBinding->setTarget(d->property(name));
            QDeclarativePropertyPrivate::setBinding(d->property(name), newBinding, QDeclarativePropertyPrivate::DontRemoveBinding | QDeclarativePropertyPrivate::BypassInterceptor);
        } else {
            QDeclarativeAction action;
            action.restore = restoreEntryValues();
            action.property = d->property(name);
            action.fromValue = action.property.read();
            action.specifiedObject = object();
            action.specifiedProperty = name;


            if (d->isExplicit) {
                action.toValue = newExpression->evaluate();
            } else {
                QDeclarativeBinding *newBinding = new QDeclarativeBinding(newExpression->expression(), object(), qmlContext(this));
                newBinding->setTarget(d->property(name));
                action.toBinding = newBinding;
                action.deletableToBinding = true;

                state()->addEntryToRevertList(action);
                QDeclarativeAbstractBinding *oldBinding = QDeclarativePropertyPrivate::binding(action.property);
                if (oldBinding)
                    oldBinding->setEnabled(false, QDeclarativePropertyPrivate::DontRemoveBinding | QDeclarativePropertyPrivate::BypassInterceptor);

                QDeclarativePropertyPrivate::setBinding(action.property, newBinding, QDeclarativePropertyPrivate::DontRemoveBinding | QDeclarativePropertyPrivate::BypassInterceptor);
            }
        }
    }
    // what about the signal handler?
}

QVariant QDeclarativePropertyChanges::property(const QString &name) const
{
    Q_D(const QDeclarativePropertyChanges);
    typedef QPair<QString, QVariant> PropertyEntry;
    typedef QDeclarativePropertyChangesPrivate::ExpressionChange ExpressionEntry;

    QListIterator<PropertyEntry> propertyIterator(d->properties);
    while (propertyIterator.hasNext()) {
        const PropertyEntry &entry = propertyIterator.next();
        if (entry.first == name) {
            return entry.second;
        }
    }

    QListIterator<ExpressionEntry> expressionIterator(d->expressions);
    while (expressionIterator.hasNext()) {
        const ExpressionEntry &entry = expressionIterator.next();
        if (entry.name == name) {
            return QVariant(entry.expression->expression());
        }
    }

    return QVariant();
}

void QDeclarativePropertyChanges::removeProperty(const QString &name)
{
    Q_D(QDeclarativePropertyChanges);
    typedef QPair<QString, QVariant> PropertyEntry;
    typedef QDeclarativePropertyChangesPrivate::ExpressionChange ExpressionEntry;

    QMutableListIterator<ExpressionEntry> expressionIterator(d->expressions);
    while (expressionIterator.hasNext()) {
        const ExpressionEntry &entry = expressionIterator.next();
        if (entry.name == name) {
            expressionIterator.remove();
            state()->removeEntryFromRevertList(object(), name);
            return;
        }
    }

    QMutableListIterator<PropertyEntry> propertyIterator(d->properties);
    while (propertyIterator.hasNext()) {
        const PropertyEntry &entry = propertyIterator.next();
        if (entry.first == name) {
            propertyIterator.remove();
            state()->removeEntryFromRevertList(object(), name);
            return;
        }
    }
}

QVariant QDeclarativePropertyChanges::value(const QString &name) const
{
    Q_D(const QDeclarativePropertyChanges);
    typedef QPair<QString, QVariant> PropertyEntry;

    QListIterator<PropertyEntry> propertyIterator(d->properties);
    while (propertyIterator.hasNext()) {
        const PropertyEntry &entry = propertyIterator.next();
        if (entry.first == name) {
            return entry.second;
        }
    }

    return QVariant();
}

QString QDeclarativePropertyChanges::expression(const QString &name) const
{
    Q_D(const QDeclarativePropertyChanges);
    typedef QDeclarativePropertyChangesPrivate::ExpressionChange ExpressionEntry;

    QListIterator<ExpressionEntry> expressionIterator(d->expressions);
    while (expressionIterator.hasNext()) {
        const ExpressionEntry &entry = expressionIterator.next();
        if (entry.name == name) {
            return entry.expression->expression();
        }
    }

    return QString();
}

void QDeclarativePropertyChanges::detachFromState()
{
    if (state())
        state()->removeAllEntriesFromRevertList(object());
}

void QDeclarativePropertyChanges::attachToState()
{
    if (state())
        state()->addEntriesToRevertList(actions());
}

QT_END_NAMESPACE