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** This file is part of the QtQml module of the Qt Toolkit.
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** Foundation and appearing in the file LICENSE.GPL included in the
** packaging of this file.  Please review the following information to
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#include "qqmljavascriptexpression_p.h"

#include <private/qqmlexpression_p.h>
#include <private/qqmlcontextwrapper_p.h>
#include <private/qv4value_p.h>
#include <private/qv4functionobject_p.h>
#include <private/qv4script_p.h>
#include <private/qv4errorobject_p.h>
#include <private/qv4scopedvalue_p.h>

QT_BEGIN_NAMESPACE

bool QQmlDelayedError::addError(QQmlEnginePrivate *e)
{
    if (!e) return false;

    if (e->inProgressCreations == 0) return false; // Not in construction

    if (prevError) return true; // Already in error chain

    prevError = &e->erroredBindings;
    nextError = e->erroredBindings;
    e->erroredBindings = this;
    if (nextError) nextError->prevError = &nextError;

    return true;
}

void QQmlDelayedError::setErrorLocation(const QUrl &url, quint16 line, quint16 column)
{
    m_error.setUrl(url);
    m_error.setLine(line);
    m_error.setColumn(column);
}

void QQmlDelayedError::setErrorDescription(const QString &description)
{
    m_error.setDescription(description);
}

void QQmlDelayedError::setErrorObject(QObject *object)
{
    m_error.setObject(object);
}

void QQmlDelayedError::catchJavaScriptException(QV4::ExecutionContext *context)
{
    m_error = QV4::ExecutionEngine::convertJavaScriptException(context);
}


QQmlJavaScriptExpression::QQmlJavaScriptExpression(VTable *v)
: m_vtable(v)
{
}

QQmlJavaScriptExpression::~QQmlJavaScriptExpression()
{
    clearGuards();
    if (m_scopeObject.isT2()) // notify DeleteWatcher of our deletion.
        m_scopeObject.asT2()->_s = 0;
}

void QQmlJavaScriptExpression::setNotifyOnValueChanged(bool v)
{
    activeGuards.setFlagValue(v);
    if (!v) clearGuards();
}

void QQmlJavaScriptExpression::resetNotifyOnValueChanged()
{
    clearGuards();
}

QV4::ReturnedValue QQmlJavaScriptExpression::evaluate(QQmlContextData *context,
                                   const QV4::ValueRef function, bool *isUndefined)
{
    QV4::ExecutionEngine *v4 = QV8Engine::getV4(context->engine);
    QV4::Scope scope(v4);
    QV4::ScopedCallData callData(scope, 0);

    return evaluate(context, function, callData, isUndefined);
}

QV4::ReturnedValue QQmlJavaScriptExpression::evaluate(QQmlContextData *context,
                                   const QV4::ValueRef function,
                                   QV4::CallData *callData,
                                   bool *isUndefined)
{
    Q_ASSERT(context && context->engine);

    if (function->isUndefined()) {
        if (isUndefined)
            *isUndefined = true;
        return QV4::Encode::undefined();
    }

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

    Q_ASSERT(notifyOnValueChanged() || activeGuards.isEmpty());
    GuardCapture capture(context->engine, this);

    QQmlEnginePrivate::PropertyCapture *lastPropertyCapture = ep->propertyCapture;
    ep->propertyCapture = notifyOnValueChanged()?&capture:0;


    if (notifyOnValueChanged())
        capture.guards.copyAndClearPrepend(activeGuards);

    QQmlContextData *lastSharedContext = 0;
    QObject *lastSharedScope = 0;

    // All code that follows must check with watcher before it accesses data members
    // incase we have been deleted.
    DeleteWatcher watcher(this);

    QV4::ExecutionEngine *v4 = QV8Engine::getV4(ep->v8engine());
    QV4::Scope scope(v4);
    QV4::ScopedValue result(scope, QV4::Primitive::undefinedValue());
    QV4::ExecutionContext *ctx = v4->current;
    try {
        callData->thisObject = ep->v8engine()->global();
        if (scopeObject() && requiresThisObject()) {
            QV4::ScopedValue value(scope, QV4::QObjectWrapper::wrap(ctx->engine, scopeObject()));
            if (value->isObject())
                callData->thisObject = value;
        }

        result = function->asFunctionObject()->call(callData);

        if (isUndefined)
            *isUndefined = result->isUndefined();

        if (!watcher.wasDeleted() && hasDelayedError())
            delayedError()->clearError();
    } catch (...) {
        if (watcher.wasDeleted())
            ctx->catchException(); // ignore exception
        else
            delayedError()->catchJavaScriptException(ctx);
        if (isUndefined)
            *isUndefined = true;
    }

    if (capture.errorString) {
        for (int ii = 0; ii < capture.errorString->count(); ++ii)
            qWarning("%s", qPrintable(capture.errorString->at(ii)));
        delete capture.errorString;
        capture.errorString = 0;
    }

    while (Guard *g = capture.guards.takeFirst())
        g->Delete();

    ep->propertyCapture = lastPropertyCapture;

    return result.asReturnedValue();
}

void QQmlJavaScriptExpression::GuardCapture::captureProperty(QQmlNotifier *n)
{
    if (expression) {

        // Try and find a matching guard
        while (!guards.isEmpty() && !guards.first()->isConnected(n))
            guards.takeFirst()->Delete();

        Guard *g = 0;
        if (!guards.isEmpty()) {
            g = guards.takeFirst();
            g->cancelNotify();
            Q_ASSERT(g->isConnected(n));
        } else {
            g = Guard::New(expression, engine);
            g->connect(n);
        }

        expression->activeGuards.prepend(g);
    }
}

/*! \internal
    \reimp

    \a n is in the signal index range (see QObjectPrivate::signalIndex()).
*/
void QQmlJavaScriptExpression::GuardCapture::captureProperty(QObject *o, int c, int n)
{
    if (expression) {
        if (n == -1) {
            if (!errorString) {
                errorString = new QStringList;
                QString preamble = QLatin1String("QQmlExpression: Expression ") +
                                   expression->m_vtable->expressionIdentifier(expression) +
                                   QLatin1String(" depends on non-NOTIFYable properties:");
                errorString->append(preamble);
            }

            const QMetaObject *metaObj = o->metaObject();
            QMetaProperty metaProp = metaObj->property(c);

            QString error = QLatin1String("    ") +
                            QString::fromUtf8(metaObj->className()) +
                            QLatin1String("::") +
                            QString::fromUtf8(metaProp.name());
            errorString->append(error);
        } else {

            // Try and find a matching guard
            while (!guards.isEmpty() && !guards.first()->isConnected(o, n))
                guards.takeFirst()->Delete();

            Guard *g = 0;
            if (!guards.isEmpty()) {
                g = guards.takeFirst();
                g->cancelNotify();
                Q_ASSERT(g->isConnected(o, n));
            } else {
                g = Guard::New(expression, engine);
                g->connect(o, n, engine);
            }

            expression->activeGuards.prepend(g);
        }
    }
}

void QQmlJavaScriptExpression::clearError()
{
    if (m_vtable.hasValue()) {
        m_vtable.value().clearError();
        m_vtable.value().removeError();
    }
}

QQmlError QQmlJavaScriptExpression::error(QQmlEngine *engine) const
{
    if (m_vtable.hasValue())
        return m_vtable.constValue()->error();
    else
        return QQmlError();
}

QQmlDelayedError *QQmlJavaScriptExpression::delayedError()
{
    return &m_vtable.value();
}

QV4::ReturnedValue
QQmlJavaScriptExpression::evalFunction(QQmlContextData *ctxt, QObject *scopeObject,
                                       const QString &code, const QString &filename, quint16 line,
                                       QV4::PersistentValue *qmlscope)
{
    QQmlEngine *engine = ctxt->engine;
    QQmlEnginePrivate *ep = QQmlEnginePrivate::get(engine);

    QV4::ExecutionEngine *v4 = QV8Engine::getV4(ep->v8engine());
    QV4::ExecutionContext *ctx = v4->current;
    QV4::Scope scope(v4);

    QV4::ScopedObject qmlScopeObject(scope, QV4::QmlContextWrapper::qmlScope(ep->v8engine(), ctxt, scopeObject));
    QV4::Script script(v4, qmlScopeObject, code, filename, line);
    QV4::ScopedValue result(scope);
    try {
        script.parse();
        result = script.run();
    } catch (...) {
        QQmlError error = QV4::ExecutionEngine::convertJavaScriptException(ctx);
        if (error.description().isEmpty())
            error.setDescription(QLatin1String("Exception occurred during function evaluation"));
        if (error.line() == -1)
            error.setLine(line);
        if (error.url().isEmpty())
            error.setUrl(QUrl::fromLocalFile(filename));
        error.setObject(scopeObject);
        ep->warning(error);
        return QV4::Encode::undefined();
    }
    if (qmlscope)
        *qmlscope = qmlScopeObject;
    return result.asReturnedValue();
}

QV4::ReturnedValue QQmlJavaScriptExpression::qmlBinding(QQmlContextData *ctxt, QObject *qmlScope,
                                                       const QString &code, const QString &filename, quint16 line,
                                                       QV4::PersistentValue *qmlscope)
{
    QQmlEngine *engine = ctxt->engine;
    QQmlEnginePrivate *ep = QQmlEnginePrivate::get(engine);

    QV4::ExecutionEngine *v4 = QV8Engine::getV4(ep->v8engine());
    QV4::ExecutionContext *ctx = v4->current;
    QV4::Scope scope(v4);

    QV4::ScopedObject qmlScopeObject(scope, QV4::QmlContextWrapper::qmlScope(ep->v8engine(), ctxt, qmlScope));
    QV4::Script script(v4, qmlScopeObject, code, filename, line);
    QV4::ScopedValue result(scope);
    try {
        script.parse();
        result = script.qmlBinding();
    } catch (...) {
        QQmlError error = QV4::ExecutionEngine::convertJavaScriptException(ctx);
        if (error.description().isEmpty())
            error.setDescription(QLatin1String("Exception occurred during function evaluation"));
        if (error.line() == -1)
            error.setLine(line);
        if (error.url().isEmpty())
            error.setUrl(QUrl::fromLocalFile(filename));
        error.setObject(qmlScope);
        ep->warning(error);
        return QV4::Encode::undefined();
    }
    if (qmlscope)
        *qmlscope = qmlScopeObject;
    return result.asReturnedValue();
}


void QQmlJavaScriptExpression::clearGuards()
{
    while (Guard *g = activeGuards.takeFirst())
        g->Delete();
}

void QQmlJavaScriptExpressionGuard_callback(QQmlNotifierEndpoint *e, void **)
{
    QQmlJavaScriptExpression *expression =
        static_cast<QQmlJavaScriptExpressionGuard *>(e)->expression;

    expression->m_vtable->expressionChanged(expression);
}

QT_END_NAMESPACE