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
  ** https://www.gnu.org/licenses/gpl-3.0.html.
  **
  ** $QT_END_LICENSE$
  **
  ****************************************************************************/
  
  #ifndef QQMLCHANGESET_P_H
  #define QQMLCHANGESET_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 <QtCore/qdebug.h>
  #include <QtCore/qvector.h>
  #include <QtQml/private/qtqmlglobal_p.h>
  
  QT_BEGIN_NAMESPACE
  
  class Q_QML_PRIVATE_EXPORT QQmlChangeSet
  {
  public:
      struct MoveKey
      {
          MoveKey() : moveId(-1), offset(0) {}
          MoveKey(int moveId, int offset) : moveId(moveId), offset(offset) {}
          int moveId;
          int offset;
      };
  
      struct Change
      {
          Change() : index(0), count(0), moveId(-1) {}
          Change(int index, int count, int moveId = -1, int offset = 0)
              : index(index), count(count), moveId(moveId), offset(offset) {}
  
          int index;
          int count;
          int moveId;
          int offset;
  
          bool isMove() const { return moveId >= 0; }
  
          MoveKey moveKey(int index) const {
              return MoveKey(moveId, index - Change::index + offset); }
  
          int start() const { return index; }
          int end() const { return index + count; }
      };
  
      QQmlChangeSet();
      QQmlChangeSet(const QQmlChangeSet &changeSet);
      ~QQmlChangeSet();
  
      QQmlChangeSet &operator =(const QQmlChangeSet &changeSet);
  
      const QVector<Change> &removes() const { return m_removes; }
      const QVector<Change> &inserts() const { return m_inserts; }
      const QVector<Change> &changes() const { return m_changes; }
  
      void insert(int index, int count);
      void remove(int index, int count);
      void move(int from, int to, int count, int moveId);
      void change(int index, int count);
  
      void insert(const QVector<Change> &inserts);
      void remove(const QVector<Change> &removes, QVector<Change> *inserts = 0);
      void move(const QVector<Change> &removes, const QVector<Change> &inserts);
      void change(const QVector<Change> &changes);
      void apply(const QQmlChangeSet &changeSet);
  
      bool isEmpty() const { return m_removes.empty() && m_inserts.empty() && m_changes.isEmpty(); }
  
      void clear()
      {
          m_removes.clear();
          m_inserts.clear();
          m_changes.clear();
          m_difference = 0;
      }
  
      int difference() const { return m_difference; }
  
  private:
      void remove(QVector<Change> *removes, QVector<Change> *inserts);
      void change(QVector<Change> *changes);
  
      QVector<Change> m_removes;
      QVector<Change> m_inserts;
      QVector<Change> m_changes;
      int m_difference;
  };
  
  Q_DECLARE_TYPEINFO(QQmlChangeSet::Change, Q_PRIMITIVE_TYPE);
  Q_DECLARE_TYPEINFO(QQmlChangeSet::MoveKey, Q_PRIMITIVE_TYPE);
  
  inline uint qHash(const QQmlChangeSet::MoveKey &key) { return qHash(qMakePair(key.moveId, key.offset)); }
  inline bool operator ==(const QQmlChangeSet::MoveKey &l, const QQmlChangeSet::MoveKey &r) {
      return l.moveId == r.moveId && l.offset == r.offset; }
  
  Q_QML_PRIVATE_EXPORT QDebug operator <<(QDebug debug, const QQmlChangeSet::Change &change);
  Q_QML_PRIVATE_EXPORT QDebug operator <<(QDebug debug, const QQmlChangeSet &change);
  
  QT_END_NAMESPACE
  
  #endif
  