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#ifndef QPROPERTYBINDING_P_H
#define QPROPERTYBINDING_P_H

//
//  W A R N I N G
//  -------------
//
// This file is not part of the Qt API.  It exists for the convenience
// of qapplication_*.cpp, qwidget*.cpp and qfiledialog.cpp.  This header
// file may change from version to version without notice, or even be removed.
//
// We mean it.
//

#include <QtCore/qglobal.h>
#include <QtCore/qshareddata.h>
#include <QtCore/qscopedpointer.h>
#include <vector>
#include <functional>

#include "qproperty_p.h"

QT_BEGIN_NAMESPACE

class Q_CORE_EXPORT QPropertyBindingPrivate : public QSharedData
{
private:
    friend struct QPropertyBasePointer;

    QUntypedPropertyBinding::BindingEvaluationFunction evaluationFunction;

    QPropertyObserverPointer firstObserver;
    std::array<QPropertyObserver, 4> inlineDependencyObservers;
    QScopedPointer<std::vector<QPropertyObserver>> heapObservers;
    // ### merge with inline dependency observer storage
    void *staticObserver = nullptr;
    void (*staticObserverCallback)(void*) = nullptr;

    void *propertyDataPtr = nullptr;

    QPropertyBindingSourceLocation location;
    QPropertyBindingError error;

    QMetaType metaType;

    bool dirty = false;
    bool updating = false;

public:
    // public because the auto-tests access it, too.
    size_t dependencyObserverCount = 0;

    QPropertyBindingPrivate(const QMetaType &metaType, QUntypedPropertyBinding::BindingEvaluationFunction evaluationFunction,
                            const QPropertyBindingSourceLocation &location)
        : evaluationFunction(std::move(evaluationFunction))
        , location(location)
        , metaType(metaType)
    {}
    virtual ~QPropertyBindingPrivate();

    void setDirty(bool d) { dirty = d; }
    void setProperty(void *propertyPtr) { propertyDataPtr = propertyPtr; }
    void setStaticObserver(void *observer, void (*callback)(void*)) { staticObserver = observer; staticObserverCallback = callback; }
    void prependObserver(QPropertyObserverPointer observer) {
        observer.ptr->prev = const_cast<QPropertyObserver **>(&firstObserver.ptr);
        firstObserver = observer;
    }

    QPropertyObserverPointer takeObservers()
    {
        auto observers = firstObserver;
        firstObserver.ptr = nullptr;
        return observers;
    }

    void clearDependencyObservers() {
        for (size_t i = 0; i < inlineDependencyObservers.size(); ++i) {
            QPropertyObserver empty;
            qSwap(inlineDependencyObservers[i], empty);
        }
        if (heapObservers)
            heapObservers->clear();
        dependencyObserverCount = 0;
    }
    QPropertyObserverPointer allocateDependencyObserver() {
        if (dependencyObserverCount < inlineDependencyObservers.size()) {
            ++dependencyObserverCount;
            return {&inlineDependencyObservers[dependencyObserverCount - 1]};
        }
        ++dependencyObserverCount;
        if (!heapObservers)
            heapObservers.reset(new std::vector<QPropertyObserver>());
        return {&heapObservers->emplace_back()};
    }

    QPropertyBindingSourceLocation sourceLocation() const { return location; }
    QPropertyBindingError bindingError() const { return error; }
    QMetaType valueMetaType() const { return metaType; }

    void unlinkAndDeref();

    void markDirtyAndNotifyObservers();
    bool evaluateIfDirtyAndReturnTrueIfValueChanged();

    static QPropertyBindingPrivate *get(const QUntypedPropertyBinding &binding)
    { return binding.d.data(); }
};

QT_END_NAMESPACE

#endif // QPROPERTYBINDING_P_H