/****************************************************************************

**

** Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies).

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** Contact: Nokia Corporation (qt-info@nokia.com)

**

** This file is part of the QtDeclarative module of the Qt Toolkit.

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** No Commercial Usage

** This file contains pre-release code and may not be distributed.

** You may use this file in accordance with the terms and conditions

** contained in the Technology Preview License Agreement accompanying

** this package.

**

** GNU Lesser General Public License Usage

** Alternatively, this file may be used under the terms of the GNU Lesser

** General Public License version 2.1 as published by the Free Software

** Foundation and appearing in the file LICENSE.LGPL included in the

** packaging of this file.  Please review the following information to

** ensure the GNU Lesser General Public License version 2.1 requirements

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**

** In addition, as a special exception, Nokia gives you certain additional

** rights.  These rights are described in the Nokia Qt LGPL Exception

** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.

**

** If you have questions regarding the use of this file, please contact

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** $QT_END_LICENSE$

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****************************************************************************/

#ifndef QDECLARATIVESTATE_H

#define QDECLARATIVESTATE_H

#include <qdeclarative.h>

#include <qdeclarativeproperty.h>

#include <QtCore/qobject.h>

QT_BEGIN_HEADER

QT_BEGIN_NAMESPACE

QT_MODULE(Declarative)

class QDeclarativeActionEvent;

class QDeclarativeAbstractBinding;

class QDeclarativeBinding;

class QDeclarativeExpression;

class Q_DECLARATIVE_EXPORT QDeclarativeAction

{

public:

    QDeclarativeAction();

    QDeclarativeAction(QObject *, const QString &, const QVariant &);

    QDeclarativeAction(QObject *, const QString &,

                       QDeclarativeContext *, const QVariant &);

    bool restore:1;

    bool actionDone:1;

    bool reverseEvent:1;

    bool deletableToBinding:1;

    QDeclarativeProperty property;

    QVariant fromValue;

    QVariant toValue;

    QDeclarativeAbstractBinding *fromBinding;

    QDeclarativeAbstractBinding *toBinding;

    QDeclarativeActionEvent *event;

    //strictly for matching

    QObject *specifiedObject;

    QString specifiedProperty;

    void deleteFromBinding();

};

class QDeclarativeActionEvent

{

public:

    virtual ~QDeclarativeActionEvent();

    virtual QString typeName() const;

    enum Reason { ActualChange, FastForward };

    virtual void execute(Reason reason = ActualChange);

    virtual bool isReversable();

    virtual void reverse(Reason reason = ActualChange);

    virtual void saveOriginals() {}

    virtual bool needsCopy() { return false; }

    virtual void copyOriginals(QDeclarativeActionEvent *) {}

    virtual bool isRewindable() { return isReversable(); }

    virtual void rewind() {}

    virtual void saveCurrentValues() {}

    virtual void saveTargetValues() {}

    virtual bool changesBindings();

    virtual void clearBindings();

    virtual bool override(QDeclarativeActionEvent*other);

};

//### rename to QDeclarativeStateChange?

class QDeclarativeStateGroup;

class Q_DECLARATIVE_EXPORT QDeclarativeStateOperation : public QObject

{

    Q_OBJECT

public:

    QDeclarativeStateOperation(QObject *parent = 0)

        : QObject(parent) {}

    typedef QList<QDeclarativeAction> ActionList;

    virtual ActionList actions();

protected:

    QDeclarativeStateOperation(QObjectPrivate &dd, QObject *parent = 0);

};

typedef QDeclarativeStateOperation::ActionList QDeclarativeStateActions;

class QDeclarativeTransition;

class QDeclarativeStatePrivate;

class Q_DECLARATIVE_EXPORT QDeclarativeState : public QObject

{

    Q_OBJECT

    Q_PROPERTY(QString name READ name WRITE setName)

    Q_PROPERTY(QDeclarativeBinding *when READ when WRITE setWhen)

    Q_PROPERTY(QString extend READ extends WRITE setExtends)

    Q_PROPERTY(QDeclarativeListProperty<QDeclarativeStateOperation> changes READ changes)

    Q_CLASSINFO("DefaultProperty", "changes")

    Q_CLASSINFO("DeferredPropertyNames", "changes")

public:

    QDeclarativeState(QObject *parent=0);

    virtual ~QDeclarativeState();

    QString name() const;

    void setName(const QString &);

    /*'when' is a QDeclarativeBinding to limit state changes oscillation

     due to the unpredictable order of evaluation of bound expressions*/

    bool isWhenKnown() const;

    QDeclarativeBinding *when() const;

    void setWhen(QDeclarativeBinding *);

    QString extends() const;

    void setExtends(const QString &);

    QDeclarativeListProperty<QDeclarativeStateOperation> changes();

    int operationCount() const;

    QDeclarativeStateOperation *operationAt(int) const;

    QDeclarativeState &operator<<(QDeclarativeStateOperation *);

    void apply(QDeclarativeStateGroup *, QDeclarativeTransition *, QDeclarativeState *revert);

    void cancel();

    QDeclarativeStateGroup *stateGroup() const;

    void setStateGroup(QDeclarativeStateGroup *);

Q_SIGNALS:

    void completed();

private:

    Q_DECLARE_PRIVATE(QDeclarativeState)

    Q_DISABLE_COPY(QDeclarativeState)

};

QT_END_NAMESPACE

QML_DECLARE_TYPE(QDeclarativeStateOperation)

QML_DECLARE_TYPE(QDeclarativeState)

QT_END_HEADER

#endif // QDECLARATIVESTATE_H