qdeclarativebinding_p.h

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#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 "private/qdeclarativeproperty_p.h"

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

QT_BEGIN_NAMESPACE

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

    QDeclarativeAbstractBinding();

    enum DestroyMode {
        // The binding should disconnect itself upon destroy
        DisconnectBinding,

        // The binding doesn't need to disconnect itself, but it can if it wants to.
        //
        // This is used in QDeclarativeData::destroyed() - at the point at which the bindings are
        // destroyed, the notifiers are already disconnected, so no need to disconnect each
        // binding again.
        //
        // Bindings can use this flag to speed up destruction, especially for compiled bindings
        // disconnecting a single binding might be slow.
        KeepBindingConnected
    };

    virtual void destroy(DestroyMode mode = DisconnectBinding);

    virtual QString expression() const;

    enum DisconnectMode {

        // Just this single binding is getting disconnected, other bindings remain connected and
        // should not be changed.
        DisconnectOne,

        // All bindings of the same object are getting disconnected. As an optimization, it is
        // therefore valid to disconnect all bindings in one go.
        DisconnectAll
    };

    // disconnectMode can be ignored, it is just a hint for potential optimization
    virtual void disconnect(DisconnectMode disconnectMode) = 0;

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

    QObject *object() const;
    int propertyIndex() const;

    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(QObject *, int);
    void removeFromObject();

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

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

private:
    Pointer weakPointer();

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

    QObject *m_object;
    int m_propertyIndex;
    QDeclarativeAbstractBinding **m_mePtr;
    QDeclarativeAbstractBinding **m_prevBinding;
    QDeclarativeAbstractBinding  *m_nextBinding;
    QSharedPointer<QDeclarativeAbstractBinding> m_selfPointer;
};

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 void disconnect(DisconnectMode disconnectMode);

    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 { RequiresThisObject = 0x01 };
    Q_DECLARE_FLAGS(EvaluateFlags, EvaluateFlag)

    QDeclarativeBinding(const QString &, QObject *, QDeclarativeContext *, QObject *parent=0);
    QDeclarativeBinding(const QString &, QObject *, QDeclarativeContextData *, QObject *parent=0);
    QDeclarativeBinding(void *, QDeclarativeRefCount *, QObject *, QDeclarativeContextData *, 
                        const QString &, int, QObject *parent);
    QDeclarativeBinding(const QScriptValue &, QObject *, QDeclarativeContextData *, QObject *parent=0);

    void setTarget(const QDeclarativeProperty &);
    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 void disconnect(DisconnectMode disconnectMode);

    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();
    void emitValueChanged();

private:
    Q_DECLARE_PRIVATE(QDeclarativeBinding)
};

Q_DECLARE_OPERATORS_FOR_FLAGS(QDeclarativeBinding::EvaluateFlags)

QT_END_NAMESPACE

Q_DECLARE_METATYPE(QDeclarativeBinding*)

#endif // QDECLARATIVEBINDING_P_H