qglist.h

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/****************************************************************************
** 
**
** Definition of QGList and QGListIterator classes
**
** Created : 920624
**
** Copyright (C) 1992-2000 Trolltech AS.  All rights reserved.
**
** This file is part of the tools module of the Qt GUI Toolkit.
**
** This file may be distributed under the terms of the Q Public License
** as defined by Trolltech AS of Norway and appearing in the file
** LICENSE.QPL included in the packaging of this file.
**
** This file may be distributed and/or modified under the terms of the
** GNU General Public License version 2 as published by the Free Software
** Foundation and appearing in the file LICENSE.GPL included in the
** packaging of this file.
**
** Licensees holding valid Qt Enterprise Edition or Qt Professional Edition
** licenses may use this file in accordance with the Qt Commercial License
** Agreement provided with the Software.
**
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**********************************************************************/

#ifndef QGLIST_H
#define QGLIST_H

#ifndef QT_H
#include "qcollection.h"
#endif // QT_H


/*****************************************************************************
  QLNode class (internal doubly linked list node)
 *****************************************************************************/

class Q_EXPORT QLNode
{
friend class QGList;
friend class QGListIterator;
public:
    QCollection::Item getData() { return data; }
private:
    QCollection::Item data;
    QLNode *prev;
    QLNode *next;
    QLNode( QCollection::Item d ) { data = d; }
};


/*****************************************************************************
  QGList class
 *****************************************************************************/

class Q_EXPORT QGList : public QCollection      // doubly linked generic list
{
friend class QGListIterator;
friend class QGVector;                          // needed by QGVector::toList
public:
    uint  count() const;                        // return number of nodes

#ifndef QT_NO_DATASTREAM
    QDataStream &read( QDataStream & );         // read list from stream
    QDataStream &write( QDataStream & ) const;  // write list to stream
#endif
protected:
    QGList();                                   // create empty list
    QGList( const QGList & );                   // make copy of other list
    virtual ~QGList();

    QGList &operator=( const QGList & );        // assign from other list
    bool operator==( const QGList& ) const;

    void inSort( QCollection::Item );           // add item sorted in list
    void append( QCollection::Item );           // add item at end of list
    bool insertAt( uint index, QCollection::Item ); // add item at i'th position
    void relinkNode( QLNode * );                // relink as first item
    bool removeNode( QLNode * );                // remove node
    bool remove( QCollection::Item = 0 );       // remove item (0=current)
    bool removeRef( QCollection::Item = 0 );    // remove item (0=current)
    bool removeFirst();                         // remove first item
    bool removeLast();                          // remove last item
    bool removeAt( uint index );                // remove item at i'th position
    QCollection::Item takeNode( QLNode * );     // take out node
    QCollection::Item take();                   // take out current item
    QCollection::Item takeAt( uint index );     // take out item at i'th pos
    QCollection::Item takeFirst();              // take out first item
    QCollection::Item takeLast();               // take out last item

    void sort();                        // sort all items;
    void clear();                       // remove all items

    int  findRef( QCollection::Item, bool = TRUE ); // find exact item in list
    int  find( QCollection::Item, bool = TRUE ); // find equal item in list

    uint containsRef( QCollection::Item ) const; // get number of exact matches
    uint contains( QCollection::Item )  const;  // get number of equal matches

    QCollection::Item at( uint index );         // access item at i'th pos
    int   at() const;                           // get current index
    QLNode *currentNode() const;                // get current node

    QCollection::Item get() const;              // get current item

    QCollection::Item cfirst() const;   // get ptr to first list item
    QCollection::Item clast()  const;   // get ptr to last list item
    QCollection::Item first();          // set first item in list curr
    QCollection::Item last();           // set last item in list curr
    QCollection::Item next();           // set next item in list curr
    QCollection::Item prev();           // set prev item in list curr

    void  toVector( QGVector * ) const;         // put items in vector

    virtual int compareItems( QCollection::Item, QCollection::Item );

#ifndef QT_NO_DATASTREAM
    virtual QDataStream &read( QDataStream &, QCollection::Item & );
    virtual QDataStream &write( QDataStream &, QCollection::Item ) const;
#endif
private:
    void  prepend( QCollection::Item ); // add item at start of list

    void heapSortPushDown( QCollection::Item* heap, int first, int last );

    QLNode *firstNode;                          // first node
    QLNode *lastNode;                           // last node
    QLNode *curNode;                            // current node
    int     curIndex;                           // current index
    uint    numNodes;                           // number of nodes
    QGList *iterators;                          // list of iterators

    QLNode *locate( uint );                     // get node at i'th pos
    QLNode *unlink();                           // unlink node
};


inline uint QGList::count() const
{
    return numNodes;
}

inline bool QGList::removeFirst()
{
    first();
    return remove();
}

inline bool QGList::removeLast()
{
    last();
    return remove();
}

inline int QGList::at() const
{
    return curIndex;
}

inline QCollection::Item QGList::at( uint index )
{
    QLNode *n = locate( index );
    return n ? n->data : 0;
}

inline QLNode *QGList::currentNode() const
{
    return curNode;
}

inline QCollection::Item QGList::get() const
{
    return curNode ? curNode->data : 0;
}

inline QCollection::Item QGList::cfirst() const
{
    return firstNode ? firstNode->data : 0;
}

inline QCollection::Item QGList::clast() const
{
    return lastNode ? lastNode->data : 0;
}


/*****************************************************************************
  QGList stream functions
 *****************************************************************************/

#ifndef QT_NO_DATASTREAM
Q_EXPORT QDataStream &operator>>( QDataStream &, QGList & );
Q_EXPORT QDataStream &operator<<( QDataStream &, const QGList & );
#endif

/*****************************************************************************
  QGListIterator class
 *****************************************************************************/

class Q_EXPORT QGListIterator                   // QGList iterator
{
friend class QGList;
protected:
    QGListIterator( const QGList & );
    QGListIterator( const QGListIterator & );
    QGListIterator &operator=( const QGListIterator & );
   ~QGListIterator();

    bool  atFirst() const;                      // test if at first item
    bool  atLast()  const;                      // test if at last item
    QCollection::Item     toFirst();                            // move to first item
    QCollection::Item     toLast();                             // move to last item

    QCollection::Item     get() const;                          // get current item
    QCollection::Item     operator()();                         // get current and move to next
    QCollection::Item     operator++();                         // move to next item (prefix)
    QCollection::Item     operator+=(uint);                     // move n positions forward
    QCollection::Item     operator--();                         // move to prev item (prefix)
    QCollection::Item     operator-=(uint);                     // move n positions backward

protected:
    QGList *list;                               // reference to list

private:
    QLNode  *curNode;                           // current node in list
};


inline bool QGListIterator::atFirst() const
{
    return curNode == list->firstNode;
}

inline bool QGListIterator::atLast() const
{
    return curNode == list->lastNode;
}

inline QCollection::Item QGListIterator::get() const
{
    return curNode ? curNode->data : 0;
}


#endif  // QGLIST_H