/****************************************************************************
** $Id$
**
** Implementation 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.
**
** This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
** WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
**
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** information about Qt Commercial License Agreements.
** See http://www.trolltech.com/qpl/ for QPL licensing information.
** See http://www.trolltech.com/gpl/ for GPL licensing information.
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**********************************************************************/
#include "qglist.h"
#include "qgvector.h"
#include "qdatastream.h"
#include "qvaluelist.h"
/*!
\class QLNode qglist.h
\reentrant
\ingroup collection
\brief The QLNode class is an internal class for the QPtrList template collection.
\internal
QLNode is a doubly-linked list node. It has three pointers:
\list 1
\i Pointer to the previous node.
\i Pointer to the next node.
\i Pointer to the actual data.
\endlist
It might sometimes be practical to have direct access to the list nodes
in a QPtrList, but it is seldom required.
Be very careful if you want to access the list nodes. The heap can
easily get corrupted if you make a mistake.
\sa QPtrList::currentNode(), QPtrList::removeNode(), QPtrList::takeNode()
*/
/*!
\fn QPtrCollection::Item QLNode::getData()
Returns a pointer (\c void*) to the actual data in the list node.
*/
/*!
\class QGList qglist.h
\reentrant
\ingroup collection
\brief The QGList class is an internal class for implementing Qt collection classes.
\internal
QGList is a strictly internal class that acts as a base class for
several collection classes; QPtrList, QPtrQueue and QPtrStack.
QGList has some virtual functions that can be reimplemented to
customize the subclasses, namely compareItems(), read() and
write. Normally, you do not have to reimplement any of these
functions. If you still want to reimplement them, see the QStrList
class (qstrlist.h) for an example.
*/
/* Internal helper class for QGList. Contains some optimization for
the typically case where only one iterators is activre on the list.
*/
class QGListIteratorList
{
public:
QGListIteratorList()
: list(0), iterator(0) {
}
~QGListIteratorList() {
notifyClear( TRUE );
delete list;
}
void add( QGListIterator* i ) {
if ( !iterator ) {
iterator = i;
} else if ( list ) {
list->push_front( i );
} else {
list = new QValueList<QGListIterator*>;
list->push_front( i );
}
}
void remove( QGListIterator* i ) {
if ( iterator == i ) {
iterator = 0;
} else if ( list ) {
list->remove( i );
if ( list->isEmpty() ) {
delete list;
list = 0;
}
}
}
void notifyClear( bool zeroList ) {
if ( iterator ) {
if ( zeroList )
iterator->list = 0;
iterator->curNode = 0;
}
if ( list ) {
for ( QValueList<QGListIterator*>::Iterator i = list->begin(); i != list->end(); ++i ) {
if ( zeroList )
(*i)->list = 0;
(*i)->curNode = 0;
}
}
}
void notifyRemove( QLNode* n, QLNode* curNode ) {
if ( iterator ) {
if ( iterator->curNode == n )
iterator->curNode = curNode;
}
if ( list ) {
for ( QValueList<QGListIterator*>::Iterator i = list->begin(); i != list->end(); ++i ) {
if ( (*i)->curNode == n )
(*i)->curNode = curNode;
}
}
}
private:
QValueList<QGListIterator*>* list;
QGListIterator* iterator;
};
/*****************************************************************************
Default implementation of virtual functions
*****************************************************************************/
/*!
Documented as QPtrList::compareItems().
Compares \a item1 with \a item2.
*/
int QGList::compareItems( QPtrCollection::Item item1, QPtrCollection::Item item2 )
{
return item1 != item2; // compare pointers
}
#ifndef QT_NO_DATASTREAM
/*!
\overload
Reads a collection/list item from the stream \a s and returns a reference
to the stream.
The default implementation sets \a item to 0.
\sa write()
*/
QDataStream &QGList::read( QDataStream &s, QPtrCollection::Item &item )
{
item = 0;
return s;
}
/*!
\overload
Writes a collection/list item to the stream \a s and
returns a reference to the stream.
The default implementation does nothing.
\sa read()
*/
QDataStream &QGList::write( QDataStream &s, QPtrCollection::Item ) const
{
return s;
}
#endif // QT_NO_DATASTREAM
/*****************************************************************************
QGList member functions
*****************************************************************************/
/*!
Constructs an empty list.
*/
QGList::QGList()
{
firstNode = lastNode = curNode = 0; // initialize list
numNodes = 0;
curIndex = -1;
iterators = 0; // initialize iterator list
}
/*!
Constructs a copy of \a list.
*/
QGList::QGList( const QGList & list )
: QPtrCollection( list )
{
firstNode = lastNode = curNode = 0; // initialize list
numNodes = 0;
curIndex = -1;
iterators = 0; // initialize iterator list
QLNode *n = list.firstNode;
while ( n ) { // copy all items from list
append( n->data );
n = n->next;
}
}
/*!
Removes all items from the list and destroys the list.
*/
QGList::~QGList()
{
clear();
delete iterators;
// Workaround for GCC 2.7.* bug. Compiler constructs 'static' QGList
// instances twice on the same address and therefore tries to destruct
// twice on the same address! This is insane but let's try not to crash
// here.
iterators = 0;
}
/*!
Assigns \a list to this list.
*/
QGList& QGList::operator=( const QGList &list )
{
if ( &list == this )
return *this;
clear();
if ( list.count() > 0 ) {
QLNode *n = list.firstNode;
while ( n ) { // copy all items from list
append( n->data );
n = n->next;
}
curNode = firstNode;
curIndex = 0;
}
return *this;
}
/*!
Compares this list with \a list. Returns TRUE if the lists
contain the same data, otherwise FALSE.
*/
bool QGList::operator==( const QGList &list ) const
{
if ( count() != list.count() )
return FALSE;
if ( count() == 0 )
return TRUE;
QLNode *n1 = firstNode;
QLNode *n2 = list.firstNode;
while ( n1 && n2 ) {
// should be mutable
if ( ( (QGList*)this )->compareItems( n1->data, n2->data ) != 0 )
return FALSE;
n1 = n1->next;
n2 = n2->next;
}
return TRUE;
}
/*!
\fn uint QGList::count() const
Returns the number of items in the list.
*/
/*!
Returns the node at position \a index. Sets this node to current.
*/
QLNode *QGList::locate( uint index )
{
if ( index == (uint)curIndex ) // current node ?
return curNode;
if ( !curNode && firstNode ) { // set current node
curNode = firstNode;
curIndex = 0;
}
register QLNode *node;
int distance = index - curIndex; // node distance to cur node
bool forward; // direction to traverse
if ( index >= numNodes )
return 0;
if ( distance < 0 )
distance = -distance;
if ( (uint)distance < index && (uint)distance < numNodes - index ) {
node = curNode; // start from current node
forward = index > (uint)curIndex;
} else if ( index < numNodes - index ) { // start from first node
node = firstNode;
distance = index;
forward = TRUE;
} else { // start from last node
node = lastNode;
distance = numNodes - index - 1;
if ( distance < 0 )
distance = 0;
forward = FALSE;
}
if ( forward ) { // now run through nodes
while ( distance-- )
node = node->next;
} else {
while ( distance-- )
node = node->prev;
}
curIndex = index; // must update index
return curNode = node;
}
/*!
Inserts item \a d at its sorted position in the list.
*/
void QGList::inSort( QPtrCollection::Item d )
{
int index = 0;
register QLNode *n = firstNode;
while ( n && compareItems(n->data,d) < 0 ){ // find position in list
n = n->next;
index++;
}
insertAt( index, d );
}
/*!
Inserts item \a d at the start of the list.
*/
void QGList::prepend( QPtrCollection::Item d )
{
register QLNode *n = new QLNode( newItem(d) );
Q_CHECK_PTR( n );
n->prev = 0;
if ( (n->next = firstNode) ) // list is not empty
firstNode->prev = n;
else // initialize list
lastNode = n;
firstNode = curNode = n; // curNode affected
numNodes++;
curIndex = 0;
}
/*!
Inserts item \a d at the end of the list.
*/
void QGList::append( QPtrCollection::Item d )
{
register QLNode *n = new QLNode( newItem(d) );
Q_CHECK_PTR( n );
n->next = 0;
if ( (n->prev = lastNode) ) // list is not empty
lastNode->next = n;
else // initialize list
firstNode = n;
lastNode = curNode = n; // curNode affected
curIndex = numNodes;
numNodes++;
}
/*!
Inserts item \a d at position \a index in the list.
*/
bool QGList::insertAt( uint index, QPtrCollection::Item d )
{
if ( index == 0 ) {
prepend( d );
return TRUE;
} else if ( index == numNodes ) {
append( d );
return TRUE;
}
QLNode *nextNode = locate( index );
if ( !nextNode )
return FALSE;
QLNode *prevNode = nextNode->prev;
register QLNode *n = new QLNode( newItem(d) );
Q_CHECK_PTR( n );
nextNode->prev = n;
prevNode->next = n;
n->prev = prevNode; // link new node into list
n->next = nextNode;
curNode = n; // curIndex set by locate()
numNodes++;
return TRUE;
}
/*!
Relinks node \a n and makes it the first node in the list.
*/
void QGList::relinkNode( QLNode *n )
{
if ( n == firstNode ) // already first
return;
curNode = n;
unlink();
n->prev = 0;
if ( (n->next = firstNode) ) // list is not empty
firstNode->prev = n;
else // initialize list
lastNode = n;
firstNode = curNode = n; // curNode affected
numNodes++;
curIndex = 0;
}
/*!
Unlinks the current list node and returns a pointer to this node.
*/
QLNode *QGList::unlink()
{
if ( curNode == 0 ) // null current node
return 0;
register QLNode *n = curNode; // unlink this node
if ( n == firstNode ) { // removing first node ?
if ( (firstNode = n->next) ) {
firstNode->prev = 0;
} else {
lastNode = curNode = 0; // list becomes empty
curIndex = -1;
}
} else {
if ( n == lastNode ) { // removing last node ?
lastNode = n->prev;
lastNode->next = 0;
} else { // neither last nor first node
n->prev->next = n->next;
n->next->prev = n->prev;
}
}
if ( n->next ) { // change current node
curNode = n->next;
} else if ( n->prev ) {
curNode = n->prev;
curIndex--;
}
if ( iterators )
iterators->notifyRemove( n, curNode );
numNodes--;
return n;
}
/*!
Removes the node \a n from the list.
*/
bool QGList::removeNode( QLNode *n )
{
#if defined(QT_CHECK_NULL)
if ( n == 0 || (n->prev && n->prev->next != n) ||
(n->next && n->next->prev != n) ) {
qWarning( "QGList::removeNode: Corrupted node" );
return FALSE;
}
#endif
curNode = n;
unlink(); // unlink node
deleteItem( n->data ); // deallocate this node
delete n;
curNode = firstNode;
curIndex = curNode ? 0 : -1;
return TRUE;
}
/*!
Removes the item \a d from the list. Uses compareItems() to find the item.
If \a d is 0, removes the current item.
*/
bool QGList::remove( QPtrCollection::Item d )
{
if ( d && find(d) == -1 )
return FALSE;
QLNode *n = unlink();
if ( !n )
return FALSE;
deleteItem( n->data );
delete n;
return TRUE;
}
/*!
Removes the item \a d from the list.
*/
bool QGList::removeRef( QPtrCollection::Item d )
{
if ( findRef(d) == -1 )
return FALSE;
QLNode *n = unlink();
if ( !n )
return FALSE;
deleteItem( n->data );
delete n;
return TRUE;
}
/*!
\fn bool QGList::removeFirst()
Removes the first item in the list.
*/
/*!
\fn bool QGList::removeLast()
Removes the last item in the list.
*/
/*!
Removes the item at position \a index from the list.
*/
bool QGList::removeAt( uint index )
{
if ( !locate(index) )
return FALSE;
QLNode *n = unlink();
if ( !n )
return FALSE;
deleteItem( n->data );
delete n;
return TRUE;
}
/*!
Replaces the item at index \a index with \a d.
*/
bool QGList::replaceAt( uint index, QPtrCollection::Item d )
{
QLNode *n = locate( index );
if ( !n )
return FALSE;
if ( n->data != d ) {
deleteItem( n->data );
n->data = newItem( d );
}
return TRUE;
}
/*!
Takes the node \a n out of the list.
*/
QPtrCollection::Item QGList::takeNode( QLNode *n )
{
#if defined(QT_CHECK_NULL)
if ( n == 0 || (n->prev && n->prev->next != n) ||
(n->next && n->next->prev != n) ) {
qWarning( "QGList::takeNode: Corrupted node" );
return 0;
}
#endif
curNode = n;
unlink(); // unlink node
Item d = n->data;
delete n; // delete the node, not data
curNode = firstNode;
curIndex = curNode ? 0 : -1;
return d;
}
/*!
Takes the current item out of the list.
*/
QPtrCollection::Item QGList::take()
{
QLNode *n = unlink(); // unlink node
Item d = n ? n->data : 0;
delete n; // delete node, keep contents
return d;
}
/*!
Takes the item at position \a index out of the list.
*/
QPtrCollection::Item QGList::takeAt( uint index )
{
if ( !locate(index) )
return 0;
QLNode *n = unlink(); // unlink node
Item d = n ? n->data : 0;
delete n; // delete node, keep contents
return d;
}
/*!
Takes the first item out of the list.
*/
QPtrCollection::Item QGList::takeFirst()
{
first();
QLNode *n = unlink(); // unlink node
Item d = n ? n->data : 0;
delete n;
return d;
}
/*!
Takes the last item out of the list.
*/
QPtrCollection::Item QGList::takeLast()
{
last();
QLNode *n = unlink(); // unlink node
Item d = n ? n->data : 0;
delete n;
return d;
}
/*!
Removes all items from the list.
*/
void QGList::clear()
{
register QLNode *n = firstNode;
firstNode = lastNode = curNode = 0; // initialize list
numNodes = 0;
curIndex = -1;
if ( iterators )
iterators->notifyClear( FALSE );
QLNode *prevNode;
while ( n ) { // for all nodes ...
deleteItem( n->data ); // deallocate data
prevNode = n;
n = n->next;
delete prevNode; // deallocate node
}
}
/*!
Finds item \a d in the list. If \a fromStart is TRUE the search
begins at the first node; otherwise it begins at the current node.
*/
int QGList::findRef( QPtrCollection::Item d, bool fromStart )
{
register QLNode *n;
int index;
if ( fromStart ) { // start from first node
n = firstNode;
index = 0;
} else { // start from current node
n = curNode;
index = curIndex;
}
while ( n && n->data != d ) { // find exact match
n = n->next;
index++;
}
curNode = n;
curIndex = n ? index : -1;
return curIndex; // return position of item
}
/*!
Finds item \a d in the list using compareItems(). If \a fromStart is
TRUE the search begins at the first node; otherwise it begins at the
current node.
*/
int QGList::find( QPtrCollection::Item d, bool fromStart )
{
register QLNode *n;
int index;
if ( fromStart ) { // start from first node
n = firstNode;
index = 0;
} else { // start from current node
n = curNode;
index = curIndex;
}
while ( n && compareItems(n->data,d) ){ // find equal match
n = n->next;
index++;
}
curNode = n;
curIndex = n ? index : -1;
return curIndex; // return position of item
}
/*!
Counts the number item \a d occurs in the list.
*/
uint QGList::containsRef( QPtrCollection::Item d ) const
{
register QLNode *n = firstNode;
uint count = 0;
while ( n ) { // for all nodes...
if ( n->data == d ) // count # exact matches
count++;
n = n->next;
}
return count;
}
/*!
Counts the number of times item \a d occurs in the list. Uses
compareItems().
*/
uint QGList::contains( QPtrCollection::Item d ) const
{
register QLNode *n = firstNode;
uint count = 0;
QGList *that = (QGList*)this; // mutable for compareItems()
while ( n ) { // for all nodes...
if ( !that->compareItems(n->data,d) ) // count # equal matches
count++;
n = n->next;
}
return count;
}
/*!
\overload QPtrCollection::Item QGList::at( uint index )
Sets the item at position \a index to the current item.
*/
/*!
\fn int QGList::at() const
Returns the current index.
*/
/*!
\fn QLNode *QGList::currentNode() const
Returns the current node.
*/
/*!
\fn QPtrCollection::Item QGList::get() const
Returns the current item.
*/
/*!
\fn QPtrCollection::Item QGList::cfirst() const
Returns the first item in the list.
*/
/*!
\fn QPtrCollection::Item QGList::clast() const
Returns the last item in the list.
*/
/*!
Returns the first list item. Sets this to current.
*/
QPtrCollection::Item QGList::first()
{
if ( firstNode ) {
curIndex = 0;
return (curNode=firstNode)->data;
}
return 0;
}
/*!
Returns the last list item. Sets this to current.
*/
QPtrCollection::Item QGList::last()
{
if ( lastNode ) {
curIndex = numNodes-1;
return (curNode=lastNode)->data;
}
return 0;
}
/*!
Returns the next list item (after current). Sets this to current.
*/
QPtrCollection::Item QGList::next()
{
if ( curNode ) {
if ( curNode->next ) {
curIndex++;
curNode = curNode->next;
return curNode->data;
}
curIndex = -1;
curNode = 0;
}
return 0;
}
/*!
Returns the previous list item (before current). Sets this to current.
*/
QPtrCollection::Item QGList::prev()
{
if ( curNode ) {
if ( curNode->prev ) {
curIndex--;
curNode = curNode->prev;
return curNode->data;
}
curIndex = -1;
curNode = 0;
}
return 0;
}
/*!
Converts the list to a vector, \a vector.
*/
void QGList::toVector( QGVector *vector ) const
{
vector->clear();
if ( !vector->resize( count() ) )
return;
register QLNode *n = firstNode;
uint i = 0;
while ( n ) {
vector->insert( i, n->data );
n = n->next;
i++;
}
}
void QGList::heapSortPushDown( QPtrCollection::Item* heap, int first, int last )
{
int r = first;
while( r <= last/2 ) {
// Node r has only one child ?
if ( last == 2*r ) {
// Need for swapping ?
if ( compareItems( heap[r], heap[ 2*r ] ) > 0 ) {
QPtrCollection::Item tmp = heap[r];
heap[ r ] = heap[ 2*r ];
heap[ 2*r ] = tmp;
}
// That's it ...
r = last;
} else {
// Node has two children
if ( compareItems( heap[r], heap[ 2*r ] ) > 0 &&
compareItems( heap[ 2*r ], heap[ 2*r+1 ] ) <= 0 ) {
// Swap with left child
QPtrCollection::Item tmp = heap[r];
heap[ r ] = heap[ 2*r ];
heap[ 2*r ] = tmp;
r *= 2;
} else if ( compareItems( heap[r], heap[ 2*r+1 ] ) > 0 &&
compareItems( heap[ 2*r+1 ], heap[ 2*r ] ) < 0 ) {
// Swap with right child
QPtrCollection::Item tmp = heap[r];
heap[ r ] = heap[ 2*r+1 ];
heap[ 2*r+1 ] = tmp;
r = 2*r+1;
} else {
// We are done
r = last;
}
}
}
}
/*! Sorts the list by the result of the virtual compareItems() function.
The Heap-Sort algorithm is used for sorting. It sorts n items with
O(n*log n) compares. This is the asymptotic optimal solution of the
sorting problem.
*/
void QGList::sort()
{
uint n = count();
if ( n < 2 )
return;
// Create the heap
QPtrCollection::Item* realheap = new QPtrCollection::Item[ n ];
// Wow, what a fake. But I want the heap to be indexed as 1...n
QPtrCollection::Item* heap = realheap - 1;
int size = 0;
QLNode* insert = firstNode;
for( ; insert != 0; insert = insert->next ) {
heap[++size] = insert->data;
int i = size;
while( i > 1 && compareItems( heap[i], heap[ i / 2 ] ) < 0 ) {
QPtrCollection::Item tmp = heap[ i ];
heap[ i ] = heap[ i/2 ];
heap[ i/2 ] = tmp;
i /= 2;
}
}
insert = firstNode;
// Now do the sorting
for ( int i = n; i > 0; i-- ) {
insert->data = heap[1];
insert = insert->next;
if ( i > 1 ) {
heap[1] = heap[i];
heapSortPushDown( heap, 1, i - 1 );
}
}
delete [] realheap;
}
/*****************************************************************************
QGList stream functions
*****************************************************************************/
#ifndef QT_NO_DATASTREAM
QDataStream &operator>>( QDataStream &s, QGList &list )
{ // read list
return list.read( s );
}
QDataStream &operator<<( QDataStream &s, const QGList &list )
{ // write list
return list.write( s );
}
/*!
Reads a list from the stream \a s.
*/
QDataStream &QGList::read( QDataStream &s )
{
uint num;
s >> num; // read number of items
clear(); // clear list
while ( num-- ) { // read all items
Item d;
read( s, d );
Q_CHECK_PTR( d );
if ( !d ) // no memory
break;
QLNode *n = new QLNode( d );
Q_CHECK_PTR( n );
if ( !n ) // no memory
break;
n->next = 0;
if ( (n->prev = lastNode) ) // list is not empty
lastNode->next = n;
else // initialize list
firstNode = n;
lastNode = n;
numNodes++;
}
curNode = firstNode;
curIndex = curNode ? 0 : -1;
return s;
}
/*!
Writes the list to the stream \a s.
*/
QDataStream &QGList::write( QDataStream &s ) const
{
s << count(); // write number of items
QLNode *n = firstNode;
while ( n ) { // write all items
write( s, n->data );
n = n->next;
}
return s;
}
#endif // QT_NO_DATASTREAM
/*****************************************************************************
QGListIterator member functions
*****************************************************************************/
/*!
\class QGListIterator qglist.h
\reentrant
\ingroup collection
\brief The QGListIterator class is an internal class for implementing QPtrListIterator.
\internal
QGListIterator is a strictly internal class that does the heavy work for
QPtrListIterator.
*/
/*!
\internal
Constructs an iterator that operates on the list \a l.
*/
QGListIterator::QGListIterator( const QGList &l )
{
list = (QGList *)&l; // get reference to list
curNode = list->firstNode; // set to first node
if ( !list->iterators ) {
list->iterators = new QGListIteratorList; // create iterator list
Q_CHECK_PTR( list->iterators );
}
list->iterators->add( this ); // attach iterator to list
}
/*!
\internal
Constructs a copy of the iterator \a it.
*/
QGListIterator::QGListIterator( const QGListIterator &it )
{
list = it.list;
curNode = it.curNode;
if ( list )
list->iterators->add( this ); // attach iterator to list
}
/*!
\internal
Assigns a copy of the iterator \a it and returns a reference to this
iterator.
*/
QGListIterator &QGListIterator::operator=( const QGListIterator &it )
{
if ( list ) // detach from old list
list->iterators->remove( this );
list = it.list;
curNode = it.curNode;
if ( list )
list->iterators->add( this ); // attach to new list
return *this;
}
/*!
\internal
Destroys the iterator.
*/
QGListIterator::~QGListIterator()
{
if ( list ) // detach iterator from list
list->iterators->remove(this);
}
/*!
\fn bool QGListIterator::atFirst() const
\internal
Returns TRUE if the iterator points to the first item, otherwise FALSE.
*/
/*!
\fn bool QGListIterator::atLast() const
\internal
Returns TRUE if the iterator points to the last item, otherwise FALSE.
*/
/*!
\internal
Sets the list iterator to point to the first item in the list.
*/
QPtrCollection::Item QGListIterator::toFirst()
{
if ( !list ) {
#if defined(QT_CHECK_NULL)
qWarning( "QGListIterator::toFirst: List has been deleted" );
#endif
return 0;
}
return list->firstNode ? (curNode = list->firstNode)->getData() : 0;
}
/*!
\internal
Sets the list iterator to point to the last item in the list.
*/
QPtrCollection::Item QGListIterator::toLast()
{
if ( !list ) {
#if defined(QT_CHECK_NULL)
qWarning( "QGListIterator::toLast: List has been deleted" );
#endif
return 0;
}
return list->lastNode ? (curNode = list->lastNode)->getData() : 0;
}
/*!
\fn QPtrCollection::Item QGListIterator::get() const
\internal
Returns the iterator item.
*/
/*!
\internal
Moves to the next item (postfix).
*/
QPtrCollection::Item QGListIterator::operator()()
{
if ( !curNode )
return 0;
QPtrCollection::Item d = curNode->getData();
curNode = curNode->next;
return d;
}
/*!
\internal
Moves to the next item (prefix).
*/
QPtrCollection::Item QGListIterator::operator++()
{
if ( !curNode )
return 0;
curNode = curNode->next;
return curNode ? curNode->getData() : 0;
}
/*!
\internal
Moves \a jumps positions forward.
*/
QPtrCollection::Item QGListIterator::operator+=( uint jumps )
{
while ( curNode && jumps-- )
curNode = curNode->next;
return curNode ? curNode->getData() : 0;
}
/*!
\internal
Moves to the previous item (prefix).
*/
QPtrCollection::Item QGListIterator::operator--()
{
if ( !curNode )
return 0;
curNode = curNode->prev;
return curNode ? curNode->getData() : 0;
}
/*!
\internal
Moves \a jumps positions backward.
*/
QPtrCollection::Item QGListIterator::operator-=( uint jumps )
{
while ( curNode && jumps-- )
curNode = curNode->prev;
return curNode ? curNode->getData() : 0;
}