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#include "qpropertybinding_p.h"
#include "qproperty_p.h"

#include <QScopedValueRollback>

QT_BEGIN_NAMESPACE

using namespace QtPrivate;

QPropertyBindingPrivate::~QPropertyBindingPrivate()
{
    if (firstObserver)
        firstObserver.unlink();
}

void QPropertyBindingPrivate::unlinkAndDeref()
{
    propertyDataPtr = nullptr;
    if (!ref.deref())
        delete this;
}

void QPropertyBindingPrivate::markDirtyAndNotifyObservers()
{
    dirty = true;
    if (firstObserver)
        firstObserver.notify(this);
}

bool QPropertyBindingPrivate::evaluateIfDirtyAndReturnTrueIfValueChanged()
{
    if (!dirty)
        return false;

    if (updating) {
        error = QPropertyBindingError(QPropertyBindingError::BindingLoop);
        return false;
    }

    QScopedValueRollback<bool> updateGuard(updating, true);

    BindingEvaluationState evaluationFrame(this);
    bool changed = false;
    auto result = evaluationFunction(/*version*/1, propertyDataPtr);
    if (auto changedPtr = std::get_if<bool>(&result))
        changed = *changedPtr;
    else if (auto errorPtr = std::get_if<QPropertyBindingError>(&result))
        error = std::move(*errorPtr);
    dirty = false;
    return changed;
}

QUntypedPropertyBinding::QUntypedPropertyBinding(QUntypedPropertyBinding::BindingEvaluationFunction function,
                                                 const QPropertyBindingSourceLocation &location)
{
    d = new QPropertyBindingPrivate(std::move(function), std::move(location));
}

QUntypedPropertyBinding::QUntypedPropertyBinding(QUntypedPropertyBinding &&other)
    : d(std::move(other.d))
{
}

QUntypedPropertyBinding::QUntypedPropertyBinding(const QUntypedPropertyBinding &other)
    : d(other.d)
{
}

QUntypedPropertyBinding &QUntypedPropertyBinding::operator=(const QUntypedPropertyBinding &other)
{
    d = other.d;
    return *this;
}

QUntypedPropertyBinding &QUntypedPropertyBinding::operator=(QUntypedPropertyBinding &&other)
{
    d = std::move(other.d);
    return *this;
}

QUntypedPropertyBinding::QUntypedPropertyBinding(const QPropertyBindingPrivatePtr &priv)
    : d(priv)
{
}

QUntypedPropertyBinding::~QUntypedPropertyBinding()
{
}

bool QUntypedPropertyBinding::isNull() const
{
    return !d;
}

QPropertyBindingError QUntypedPropertyBinding::error() const
{
    if (!d)
        return QPropertyBindingError();
    return d->error;
}

QT_END_NAMESPACE