/****************************************************************************
**
** Copyright (C) 2012 Nokia Corporation and/or its subsidiary(-ies).
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** This file is part of the QtDeclarative module of the Qt Toolkit.
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** rights. These rights are described in the Nokia Qt LGPL Exception
** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
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** Alternatively, this file may be used under the terms of the GNU General
** Public License version 3.0 as published by the Free Software Foundation
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** file. Please review the following information to ensure the GNU General
** Public License version 3.0 requirements will be met:
** http://www.gnu.org/copyleft/gpl.html.
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** Alternatively, this file may be used in accordance with the terms and
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** $QT_END_LICENSE$
**
****************************************************************************/

#ifndef QDECLARATIVEBINDING_P_H
#define QDECLARATIVEBINDING_P_H

//
//  W A R N I N G
//  -------------
//
// This file is not part of the Qt API.  It exists purely as an
// implementation detail.  This header file may change from version to
// version without notice, or even be removed.
//
// We mean it.
//

#include "qdeclarative.h"
#include "qdeclarativepropertyvaluesource.h"
#include "qdeclarativeexpression.h"
#include "qdeclarativeproperty.h"
#include "qdeclarativeproperty_p.h"

#include <QtCore/QObject>
#include <QtCore/QMetaProperty>

#include <private/qpointervaluepair_p.h>

QT_BEGIN_NAMESPACE

class Q_DECLARATIVE_PRIVATE_EXPORT QDeclarativeAbstractBinding
{
public:
    typedef QWeakPointer<QDeclarativeAbstractBinding> Pointer;

    QDeclarativeAbstractBinding();

    virtual void destroy();

    virtual QString expression() const;

    enum Type { PropertyBinding, ValueTypeProxy };
    virtual Type bindingType() const { return PropertyBinding; }

    // Should return the encoded property index for the binding.  Should return this value
    // even if the binding is not enabled or added to an object.
    // Encoding is:  coreIndex | (valueTypeIndex << 24)
    virtual int propertyIndex() const = 0;
    // Should return the object for the binding.  Should return this object even if the
    // binding is not enabled or added to the object.
    virtual QObject *object() const = 0;

    void setEnabled(bool e) { setEnabled(e, QDeclarativePropertyPrivate::DontRemoveBinding); }
    virtual void setEnabled(bool, QDeclarativePropertyPrivate::WriteFlags) = 0;

    void update() { update(QDeclarativePropertyPrivate::DontRemoveBinding); }
    virtual void update(QDeclarativePropertyPrivate::WriteFlags) = 0;

    void addToObject();
    void removeFromObject();

    static inline Pointer getPointer(QDeclarativeAbstractBinding *p);

protected:
    virtual ~QDeclarativeAbstractBinding();
    void clear();

    // Called by QDeclarativePropertyPrivate to "move" a binding to a different property.
    // This is only used for alias properties, and only used by QDeclarativeBinding not
    // V8 or V4 bindings.  The default implementation qFatal()'s to ensure that the
    // method is never called for V4 or V8 bindings.
    virtual void retargetBinding(QObject *, int);
private:
    Pointer weakPointer();

    friend class QDeclarativeData;
    friend class QDeclarativeComponentPrivate;
    friend class QDeclarativeValueTypeProxyBinding;
    friend class QDeclarativePropertyPrivate;
    friend class QDeclarativeVME;
    friend class QtSharedPointer::ExternalRefCount<QDeclarativeAbstractBinding>;

    typedef QSharedPointer<QDeclarativeAbstractBinding> SharedPointer;
    // To save memory, we also store the rarely used weakPointer() instance in here
    QPointerValuePair<QDeclarativeAbstractBinding*, SharedPointer> m_mePtr;

    QDeclarativeAbstractBinding **m_prevBinding;
    QDeclarativeAbstractBinding  *m_nextBinding;
};

class QDeclarativeValueTypeProxyBinding : public QDeclarativeAbstractBinding
{
public:
    QDeclarativeValueTypeProxyBinding(QObject *o, int coreIndex);

    virtual Type bindingType() const { return ValueTypeProxy; }

    virtual void setEnabled(bool, QDeclarativePropertyPrivate::WriteFlags);
    virtual void update(QDeclarativePropertyPrivate::WriteFlags);
    virtual int propertyIndex() const;
    virtual QObject *object() const;

    QDeclarativeAbstractBinding *binding(int propertyIndex);

    void removeBindings(quint32 mask);

protected:
    ~QDeclarativeValueTypeProxyBinding();

private:
    void recursiveEnable(QDeclarativeAbstractBinding *, QDeclarativePropertyPrivate::WriteFlags);
    void recursiveDisable(QDeclarativeAbstractBinding *);

    friend class QDeclarativeAbstractBinding;
    QObject *m_object;
    int m_index;
    QDeclarativeAbstractBinding *m_bindings;
};

class QDeclarativeContext;
class QDeclarativeBindingPrivate;
class Q_DECLARATIVE_PRIVATE_EXPORT QDeclarativeBinding : public QDeclarativeExpression,
                                                         public QDeclarativeAbstractBinding
{
Q_OBJECT
public:
    enum EvaluateFlag { None = 0x00, RequiresThisObject = 0x01 };
    Q_DECLARE_FLAGS(EvaluateFlags, EvaluateFlag)

    QDeclarativeBinding(const QString &, QObject *, QDeclarativeContext *, QObject *parent=0);
    QDeclarativeBinding(const QString &, QObject *, QDeclarativeContextData *, QObject *parent=0);
    QDeclarativeBinding(const QString &, bool isRewritten, QObject *, QDeclarativeContextData *, 
                        const QString &url, int lineNumber, int columnNumber = 0, QObject *parent=0);
    QDeclarativeBinding(void *, QObject *, QDeclarativeContextData *, QObject *parent=0);

    void setTarget(const QDeclarativeProperty &);
    void setTarget(QObject *, const QDeclarativePropertyData &, QDeclarativeContextData *);
    QDeclarativeProperty property() const;

    void setEvaluateFlags(EvaluateFlags flags);
    EvaluateFlags evaluateFlags() const;

    bool enabled() const;

    // Inherited from  QDeclarativeAbstractBinding
    virtual void setEnabled(bool, QDeclarativePropertyPrivate::WriteFlags flags);
    virtual void update(QDeclarativePropertyPrivate::WriteFlags flags);
    virtual QString expression() const;
    virtual int propertyIndex() const;
    virtual QObject *object() const;
    virtual void retargetBinding(QObject *, int);

    typedef int Identifier;
    static Identifier Invalid;
    static QDeclarativeBinding *createBinding(Identifier, QObject *, QDeclarativeContext *,
                                              const QString &, int, QObject *parent=0);


public Q_SLOTS:
    void update() { update(QDeclarativePropertyPrivate::DontRemoveBinding); }

protected:
    ~QDeclarativeBinding();

private:
    Q_DECLARE_PRIVATE(QDeclarativeBinding)
};

Q_DECLARE_OPERATORS_FOR_FLAGS(QDeclarativeBinding::EvaluateFlags)

QDeclarativeAbstractBinding::Pointer
QDeclarativeAbstractBinding::getPointer(QDeclarativeAbstractBinding *p)
{
    return p ? p->weakPointer() : Pointer();
}

QT_END_NAMESPACE

Q_DECLARE_METATYPE(QDeclarativeBinding*)

#endif // QDECLARATIVEBINDING_P_H