text: /****************************************************************************
  **
  ** Copyright (C) 2016 The Qt Company Ltd.
  ** Contact: https://www.qt.io/licensing/
  **
  ** This file is part of the QtQml module of the Qt Toolkit.
  **
  ** $QT_BEGIN_LICENSE:LGPL$
  ** Commercial License Usage
  ** Licensees holding valid commercial Qt licenses may use this file in
  ** accordance with the commercial license agreement provided with the
  ** Software or, alternatively, in accordance with the terms contained in
  ** a written agreement between you and The Qt Company. For licensing terms
  ** and conditions see https://www.qt.io/terms-conditions. For further
  ** information use the contact form at https://www.qt.io/contact-us.
  **
  ** GNU Lesser General Public License Usage
  ** Alternatively, this file may be used under the terms of the GNU Lesser
  ** General Public License version 3 as published by the Free Software
  ** Foundation and appearing in the file LICENSE.LGPL3 included in the
  ** packaging of this file. Please review the following information to
  ** ensure the GNU Lesser General Public License version 3 requirements
  ** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
  **
  ** GNU General Public License Usage
  ** Alternatively, this file may be used under the terms of the GNU
  ** General Public License version 2.0 or (at your option) the GNU General
  ** Public license version 3 or any later version approved by the KDE Free
  ** Qt Foundation. The licenses are as published by the Free Software
  ** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
  ** included in the packaging of this file. Please review the following
  ** information to ensure the GNU General Public License requirements will
  ** be met: https://www.gnu.org/licenses/gpl-2.0.html and
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  **
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  **
  ****************************************************************************/
  
  #ifndef QQMLBINDING_P_H
  #define QQMLBINDING_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 "qqml.h"
  #include "qqmlpropertyvaluesource.h"
  #include "qqmlexpression.h"
  #include "qqmlproperty.h"
  #include "qqmlscriptstring.h"
  #include "qqmlproperty_p.h"
  
  #include <QtCore/QObject>
  #include <QtCore/QMetaProperty>
  
  #include <private/qqmlabstractbinding_p.h>
  #include <private/qqmljavascriptexpression_p.h>
  
  QT_BEGIN_NAMESPACE
  
  class QQmlContext;
  class Q_QML_PRIVATE_EXPORT QQmlBinding : public QQmlJavaScriptExpression,
                                           public QQmlAbstractBinding
  {
      friend class QQmlAbstractBinding;
  public:
      static QQmlBinding *create(const QQmlPropertyData *, const QQmlScriptString &, QObject *, QQmlContext *);
      static QQmlBinding *create(const QQmlPropertyData *, const QString &, QObject *, QQmlContextData *,
                                 const QString &url = QString(), quint16 lineNumber = 0);
      static QQmlBinding *create(const QQmlPropertyData *property, QV4::Function *function,
                                 QObject *obj, QQmlContextData *ctxt, QV4::ExecutionContext *scope);
      ~QQmlBinding();
  
      void setTarget(const QQmlProperty &);
      void setTarget(QObject *, const QQmlPropertyData &, const QQmlPropertyData *valueType);
  
      void setNotifyOnValueChanged(bool);
  
      void refresh() Q_DECL_OVERRIDE;
  
      void setEnabled(bool, QQmlPropertyData::WriteFlags flags = QQmlPropertyData::DontRemoveBinding) Q_DECL_OVERRIDE;
      QString expression() const Q_DECL_OVERRIDE;
      void update(QQmlPropertyData::WriteFlags flags = QQmlPropertyData::DontRemoveBinding);
  
      typedef int Identifier;
      enum {
          Invalid = -1
      };
  
      QVariant evaluate();
  
      QString expressionIdentifier() const override;
      void expressionChanged() override;
  
  protected:
      virtual void doUpdate(const DeleteWatcher &watcher,
                            QQmlPropertyData::WriteFlags flags, QV4::Scope &scope) = 0;
  
      void getPropertyData(QQmlPropertyData **propertyData, QQmlPropertyData *valueTypeData) const;
      int getPropertyType() const;
  
      bool slowWrite(const QQmlPropertyData &core, const QQmlPropertyData &valueTypeData,
                     const QV4::Value &result, bool isUndefined, QQmlPropertyData::WriteFlags flags);
  
  private:
      inline bool updatingFlag() const;
      inline void setUpdatingFlag(bool);
      inline bool enabledFlag() const;
      inline void setEnabledFlag(bool);
  
      static QQmlBinding *newBinding(QQmlEnginePrivate *engine, const QQmlPropertyData *property);
  };
  
  bool QQmlBinding::updatingFlag() const
  {
      return m_target.flag();
  }
  
  void QQmlBinding::setUpdatingFlag(bool v)
  {
      m_target.setFlagValue(v);
  }
  
  bool QQmlBinding::enabledFlag() const
  {
      return m_target.flag2();
  }
  
  void QQmlBinding::setEnabledFlag(bool v)
  {
      m_target.setFlag2Value(v);
  }
  
  QT_END_NAMESPACE
  
  Q_DECLARE_METATYPE(QQmlBinding*)
  
  #endif // QQMLBINDING_P_H
  