/**************************************************************************** ** ** ** QList and QListIterator class documentation ** ** Copyright (C) 1992-2000 Trolltech AS. All rights reserved. ** ** This file is part 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. ** ** See http://www.trolltech.com/pricing.html or email sales@trolltech.com for ** 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. ** ** Contact info@trolltech.com if any conditions of this licensing are ** not clear to you. ** **********************************************************************/ /***************************************************************************** QList documentation *****************************************************************************/ /*! \class QList qlist.h \brief The QList class is a template class that provides doubly linked lists. \ingroup collection \ingroup tools In Qt 2.0 QList is only implemented as a template class. Define a template instance QList\ to create a list that operates on pointers to X, or X*. Example: \code #include #include #include class Employee { public: Employee( const QString& name, int salary ) { n=name; s=salary; } QString name() const { return n; } int salary() const { return s; } private: QString n; int s; }; void main() { QList list; // list of pointers to Employee list.setAutoDelete( TRUE ); // delete items when they are removed list.append( new Employee("Bill", 50000) ); list.append( new Employee("Steve",80000) ); list.append( new Employee("Ron", 60000) ); Employee *emp; for ( emp=list.first(); emp != 0; emp=list.next() ) printf( "%s earns %d\n", emp->name().latin1(), emp->salary() ); } \endcode Program output: \code Bill earns 50000 Steve earns 80000 Ron earns 60000 \endcode The list class is indexable and has a \link at() current index\endlink and a \link current() current item\endlink. The first item corresponds to index 0. The current index is -1 if the current item is null. QList has several member functions for traversing the list, but using a QListIterator can be more practical. Multiple list iterators may traverse the same list, independent of each other and independent of the current list item. In the example above, we make the call setAutoDelete(TRUE). Enabling auto-deletion tells the list to delete items that are removed from the list. The default is to not delete items when they are removed, but that would cause a memory leak in our example since we have no other references to the list items. List items are stored as \c void* in an internal QLNode, which also holds pointers to the next and previous list items. The functions currentNode(), removeNode() and takeNode() operate directly on the QLNode, but they should be used with care. When inserting an item into a list, only the pointer is copied, not the item itself. This is called a shallow copy. It is possible to make the list copy all of the item's data (known as a deep copy) when an item is inserted. insert(), inSort() and append() call the virtual function QCollection::newItem() for the item to be inserted. Inherit a list and reimplement it if you want deep copies. When removing an item from a list, the virtual function QCollection::deleteItem() is called. QList's default implementation is to delete the item if auto-deletion is enabled. The virtual function QGList::compareItems() can be reimplemented to compare two list items. This function is called from all list functions that need to compare list items, for instance remove(const type*). If you only want to deal with pointers, there are functions that compare pointers instead, for instance removeRef(const type*). These functions are somewhat faster than those that call compareItems(). The QStrList class in qstrlist.h is a list of \c char*. QStrList is a good example of a list that reimplements newItem(), deleteItem() and compareItems() \sa QListIterator, \link collection.html Collection Classes\endlink */ /*! \fn QList::QList() Constructs an empty list. */ /*! \fn QList::QList( const QList &list ) Constructs a copy of \e list. Each item in \e list is \link append() appended\endlink to this list. Only the pointers are copied (shallow copy). */ /*! \fn QList::~QList() Removes all items from the list and destroys the list. All list iterators that access this list will be reset. \sa setAutoDelete() */ /*! \fn QList &QList::operator=(const QList &list) Assigns \e list to this list and returns a reference to this list. This list is first cleared, then each item in \e list is \link append() appended\endlink to this list. Only the pointers are copied (shallow copy), unless newItem() has been reimplemented(). */ /*! \fn bool QList::operator==(const QList &list ) const Compares this list with \a list. Returns TRUE if the lists contain the same data, else FALSE. */ /*! \fn uint QList::count() const Returns the number of items in the list. \sa isEmpty() */ /*! \fn void QList::sort() 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. If the items in your list support operator< and operator== then you might be better off with QSortedList since it implements the compareItems() function for you using these two operators. \sa inSort() */ /*! \fn bool QList::isEmpty() const Returns TRUE if the list is empty, i.e. count() == 0. Returns FALSE otherwise. \sa count() */ /*! \fn bool QList::insert( uint index, const type *item ) Inserts the \e item at the position \e index in the list. Returns TRUE if successful, or FALSE if \e index is out of range. The valid range is 0 .. count() inclusive. The item is appended if \e index == count(). The inserted item becomes the current list item. The \e item must not be a null pointer. \sa append(), current() */ /*! \fn void QList::inSort( const type *item ) Inserts the \e item at its sorted position in the list. The sort order depends on the virtual QGList::compareItems() function. All items must be inserted with inSort() to maintain the sorting order. The inserted item becomes the current list item. The \e item must not be a null pointer. Please note that inSort is slow. If you want to insert lots of items in a list and sort after inserting then you should use sort(). inSort() takes up to O(n) compares. That means inserting n items in your list will need O(n^2) compares while sort() only needs O(n*logn) for the same task. So you inSort() only if you already have a pre-sorted list and want to insert only few additional items. \sa insert(), QGList::compareItems(), current(), sort() */ /*! \fn void QList::append( const type *item ) Inserts the \e item at the end of the list. The inserted item becomes the current list item. This is equivalent to \c insert(count(),item). The \e item must not be a null pointer. \sa insert(), current(), prepend() */ /*! \fn void QList::prepend( const type *item ) Inserts the \e item at the start of the list. The inserted item becomes the current list item. This is equivalent to \c insert(0,item). The \e item must not be a null pointer. \sa append(), insert(), current() */ /*! \fn bool QList::remove( uint index ) Removes the item at position \e index in the list. Returns TRUE if successful, or FALSE if \e index is out of range. The valid range is 0 .. (count() - 1) inclusive. The removed item is deleted if \link QCollection::setAutoDelete() auto-deletion\endlink is enabled. The item after the removed item becomes the new current list item if the removed item is not the last item in the list. If the last item is removed, the new last item becomes the current item in Qt 2.x. In 3.0, the current item will be set to null. The current item is set to null if the list becomes empty. All list iterators that refer to the removed item will be set to point to the new current item. \sa take(), clear(), setAutoDelete(), current() removeRef() */ /*! \fn bool QList::remove() Removes the current list item. Returns TRUE if successful, or FALSE if the current item is null. The removed item is deleted if \link QCollection::setAutoDelete() auto-deletion\endlink is enabled. The item after the removed item becomes the new current list item if the removed item is not the last item in the list. If the last item is removed, the new last item becomes the current item in Qt 2.x. In 3.0, the current item will be set to null. The current item is set to null if the list becomes empty. All list iterators that refer to the removed item will be set to point to the new current item. \sa take(), clear(), setAutoDelete(), current() removeRef() */ /*! \fn bool QList::remove( const type *item ) Removes the first occurrence of \e item from the list. Returns TRUE if successful, or FALSE if the item could not be found in the list. The removed item is deleted if \link QCollection::setAutoDelete() auto-deletion\endlink is enabled. The compareItems() function is called when searching for the item in the list. If compareItems() is not reimplemented, it is more efficient to call removeRef(). The item after the removed item becomes the new current list item if the removed item is not the last item in the list. If the last item is removed, the new last item becomes the current item in Qt 2.x. In 3.0, the current item will be set to null. The current item is set to null if the list becomes empty. All list iterators that refer to the removed item will be set to point to the new current item. \sa removeRef(), take(), clear(), setAutoDelete(), compareItems(), current() */ /*! \fn bool QList::removeRef( const type *item ) Removes the first occurrence of \e item from the list. Returns TRUE if successful, or FALSE if the item cannot be found in the list. The removed item is deleted if \link QCollection::setAutoDelete() auto-deletion\endlink is enabled. The list is scanned until the pointer \e item is found. It is removed if it is found. Equivalent to: \code if ( list.findRef(item) != -1 ) list.remove(); \endcode The item after the removed item becomes the new current list item if the removed item is not the last item in the list. If the last item is removed, the new last item becomes the current item in Qt 2.x. In 3.0, the current item will be set to null. The current item is set to null if the list becomes empty. All list iterators that refer to the removed item will be set to point to the new current item. \sa remove(), clear(), setAutoDelete(), current() */ /*! \fn void QList::removeNode( QLNode *node ) Removes the \e node from the list. This node must exist in the list, otherwise the program may crash. The removed item is deleted if \link QCollection::setAutoDelete() auto-deletion\endlink is enabled. The first item in the list will become the new current list item. The current item is set to null if the list becomes empty. All list iterators that refer to the removed item will be set to point to the item succeeding this item, or the preceding item if the removed item was the last item. \warning Do not call this function unless you are an expert. \sa takeNode(), currentNode() remove() removeRef() */ /*! \fn bool QList::removeFirst() Removes the first item from the list. Returns TRUE if successful, or FALSE if the list is empty. The removed item is deleted if \link QCollection::setAutoDelete() auto-deletion\endlink is enabled. The first item in the list becomes the new current list item. The current item is set to null if the list becomes empty. All list iterators that refer to the removed item will be set to point to the new current item. \sa removeLast(), setAutoDelete(), current() remove() */ /*! \fn bool QList::removeLast() Removes the last item from the list. Returns TRUE if successful, or FALSE if the list is empty. The removed item is deleted if \link QCollection::setAutoDelete() auto-deletion\endlink is enabled. The last item in the list becomes the new current list item. The current item is set to null if the list becomes empty. All list iterators that refer to the removed item will be set to point to the new current item. \sa removeFirst(), setAutoDelete(), current() */ /*! \fn type *QList::take( uint index ) Takes the item at position \e index out of the list without deleting it (even if \link QCollection::setAutoDelete() auto-deletion\endlink is enabled). Returns a pointer to the item taken out of the list, or null if the index is out of range. The valid range is 0 .. (count() - 1) inclusive. The item after the taken item becomes the new current list item if the taken item is not the last item in the list. If the last item is taken, the new last item becomes the current item in Qt 2.x. In 3.0, the current item will be set to null. The current item is set to null if the list becomes empty. All list iterators that refer to the taken item will be set to point to the new current item. \sa remove(), clear(), current() */ /*! \fn type *QList::take() Takes the current item out of the list without deleting it (even if \link QCollection::setAutoDelete() auto-deletion\endlink is enabled). Returns a pointer to the item taken out of the list, or null if the current item is null. The item after the taken item becomes the new current list item if the taken item is not the last item in the list. If the last item is taken, the new last item becomes the current item in Qt 2.x. In 3.0, the current item will be set to null. The current item is set to null if the list becomes empty. All list iterators that refer to the taken item will be set to point to the new current item. \sa remove(), clear(), current() */ /*! \fn type *QList::takeNode( QLNode *node ) Takes the \e node out of the list without deleting its item (even if \link QCollection::setAutoDelete() auto-deletion\endlink is enabled). Returns a pointer to the item taken out of the list. This node must exist in the list, otherwise the program may crash. The first item in the list becomes the new current list item. All list iterators that refer to the taken item will be set to point to the item succeeding this item, or the preceding item if the taken item was the last item. \warning Do not call this function unless you are an expert. \sa removeNode(), currentNode() */ /*! \fn void QList::clear() Removes all items from the list. The removed items are deleted if \link QCollection::setAutoDelete() auto-deletion\endlink is enabled. All list iterators that access this list will be reset. \sa remove(), take(), setAutoDelete() */ /*! \fn int QList::find( const type *item ) Finds the first occurrence of \e item in the list. If the item is found, the list sets the current item to point to the found item and returns the index of this item. If the item is not found, the list sets the current item to null, the current index to -1 and returns -1. The compareItems() function is called when searching for the item in the list. If compareItems() is not reimplemented, it is more efficient to call findRef(). \sa findNext(), findRef(), compareItems(), current() */ /*! \fn int QList::findNext( const type *item ) Finds the next occurrence of \e item in the list, starting from the current list item. If the item is found, the list sets the current item to point to the found item and returns the index of this item. If the item is not found, the list sets the current item to null, the current index to -1 and returns -1. The compareItems() function is called when searching for the item in the list. If compareItems() is not reimplemented, it is more efficient to call findNextRef(). \sa find(), findNextRef(), compareItems(), current() */ /*! \fn int QList::findRef( const type *item ) Finds the first occurrence of \e item in the list. If the item is found, the list sets the current item to point to the found item and returns the index of this item. If the item is not found, the list sets the current item to null, the current index to -1 and returns -1. Calling this function is must faster than find(), because find() compares \e item with each list item using compareItems(). This function only compares the pointers. \sa findNextRef(), find(), current() */ /*! \fn int QList::findNextRef( const type *item ) Finds the next occurrence of \e item in the list, starting from the current list item. If the item is found, the list sets the current item to point to the found item and returns the index of this item. If the item is not found, the list sets the current item to null, the current index to -1 and returns -1. Calling this function is must faster than findNext(), because findNext() compares \e item with each list item using compareItems(). This function only compares the pointers. \sa findRef(), findNext(), current() */ /*! \fn uint QList::contains( const type *item ) const Counts and returns the number of occurrences of \e item in the list. The compareItems() function is called when looking for the \e item in the list. If compareItems() is not reimplemented, it is more efficient to call containsRef(). Does not affect the current list item. \sa containsRef(), compareItems() */ /*! \fn uint QList::containsRef( const type *item ) const Counts and returns the number of occurrences of \e item in the list. Calling this function is must faster than contains(), because contains() compares \e item with each list item using compareItems(). This function only compares the pointers. Does not affect the current list item. \sa contains() */ /*! \fn type *QList::at( uint index ) Returns a pointer to the item at position \e index in the list, or null if the index is out of range. Sets the current list item to this item if \e index is valid. The valid range is 0 .. (count() - 1) inclusive. This function is very efficient. It starts scanning from the first item, last item or current item, whichever is closest to \e index. \sa current() */ /*! \fn int QList::at() const Returns the index of the current list item. The returned value is -1 if the current item is null. \sa current() */ /*! \fn type *QList::current() const Returns a pointer to the current list item. The current item may be null (implies that the current index is -1). \sa at() */ /*! \fn QLNode *QList::currentNode() const Returns a pointer to the current list node. The node can be kept and removed later using removeNode(). The advantage is that the item can be removed directly without searching the list. \warning Do not call this function unless you are an expert. \sa removeNode(), takeNode(), current() */ /*! \fn type *QList::getFirst() const Returns a pointer to the first item in the list, or null if the list is empty. Does not affect the current list item. \sa first(), getLast() */ /*! \fn type *QList::getLast() const Returns a pointer to the last item in the list, or null if the list is empty. Does not affect the current list item. \sa last(), getFirst() */ /*! \fn type *QList::first() Returns a pointer to the first item in the list and makes this the current list item, or null if the list is empty. \sa getFirst(), last(), next(), prev(), current() */ /*! \fn type *QList::last() Returns a pointer to the last item in the list and makes this the current list item, or null if the list is empty. \sa getLast(), first(), next(), prev(), current() */ /*! \fn type *QList::next() Returns a pointer to the item succeeding the current item. Returns null if the current item is null or equal to the last item. Makes the succeeding item current. If the current item before this function call was the last item, the current item will be set to null. If the current item was null, this function does nothing. \sa first(), last(), prev(), current() */ /*! \fn type *QList::prev() Returns a pointer to the item preceding the current item. Returns null if the current item is null or equal to the first item. Makes the preceding item current. If the current item before this function call was the first item, the current item will be set to null. If the current item was null, this function does nothing. \sa first(), last(), next(), current() */ /***************************************************************************** QListIterator documentation *****************************************************************************/ /*! \class QListIterator qlist.h \brief The QListIterator class provides an iterator for QList collections. \ingroup collection \ingroup tools Define a template instance QListIterator\ to create a list iterator that operates on QList\ (list of X*). Example: \code #include #include #include class Employee { public: Employee( const char *name, int salary ) { n=name; s=salary; } const char *name() const { return n; } int salary() const { return s; } private: QString n; int s; }; void main() { QList list; // list of pointers to Employee list.setAutoDelete( TRUE ); // delete items when they are removed list.append( new Employee("Bill", 50000) ); list.append( new Employee("Steve",80000) ); list.append( new Employee("Ron", 60000) ); QListIterator it(list); // iterator for employee list for ( ; it.current(); ++it ) { Employee *emp = it.current(); printf( "%s earns %d\n", emp->name().latin1(), emp->salary() ); } } \endcode Program output: \code Bill earns 50000 Steve earns 80000 Ron earns 60000 \endcode Although QList has member functions to traverse the doubly linked list structure, using a list iterator is a much more robust way of traversing the list, because multiple list iterators can operate on the same list, independent of each other and independent of the QList's current item. An iterator has its own current list item and can get the next and previous list items. It can only traverse the list, never modify it. A QList knows about all list iterators that are operating on the list. When an item is removed from the list, the list update all iterators that are pointing the removed item to point to the new current list item. Example: \code #include #include #include class Employee { ... // same as above }; void main() { QList list; // list of pointers to Employee list.setAutoDelete( TRUE ); // delete items when they are removed list.append( new Employee("Bill", 50000) ); list.append( new Employee("Steve",80000) ); list.append( new Employee("Ron", 60000) ); QListIterator it(list); list.at( 1 ); // current list item: "Steve" it.toLast(); // it: "Ron" --it; // it: "Steve" // Now, both the list and the iterator are referring the same item list.remove(); printf( "%s\n", it.current()->name().latin1() ); } \endcode Program output: \code Ron \endcode \sa QList, \link collection.html collection classes\endlink */ /*! \fn QListIterator::QListIterator( const QList &list ) Constructs an iterator for \e list. The current iterator item is set to point on the first item in the \e list. */ /*! \fn QListIterator::~QListIterator() Destroys the iterator. */ /*! \fn uint QListIterator::count() const Returns the number of items in the list this iterator operates on. \sa isEmpty() */ /*! \fn bool QListIterator::isEmpty() const Returns TRUE if the list is empty, i.e. count() == 0, otherwise FALSE. \sa count() */ /*! \fn bool QListIterator::atFirst() const Returns TRUE if the current iterator item is the first list item, otherwise FALSE. \sa toFirst(), atLast() */ /*! \fn bool QListIterator::atLast() const Returns TRUE if the current iterator item is the last list item, otherwise FALSE. \sa toLast(), atFirst() */ /*! \fn type *QListIterator::toFirst() Sets the current iterator item to point to the first list item and returns a pointer to the item. Sets the current item to null and returns null if the list is empty. \sa toLast(), atFirst() */ /*! \fn type *QListIterator::toLast() Sets the current iterator item to point to the last list item and returns a pointer to the item. Sets the current item to null and returns null if the list is empty. \sa toFirst(), atLast() */ /*! \fn QListIterator::operator type *() const Cast operator. Returns a pointer to the current iterator item. Same as current(). */ /*! \fn type *QListIterator::operator*() Asterisk operator. Returns a pointer to the current iterator item. Same as current(). */ /*! \fn type *QListIterator::current() const Returns a pointer to the current iterator item. */ /*! \fn type *QListIterator::operator()() Makes the succeeding item current and returns the original current item. If the current iterator item was the last item in the list or if it was null, null is returned. */ /*! \fn char *QStrListIterator::operator()() Makes the succeeding item current and returns the original current item. If the current iterator item was the last item in the list or if it was null, null is returned. */ /*! \fn type *QListIterator::operator++() Prefix ++ makes the succeeding item current and returns the new current item. If the current iterator item was the last item in the list or if it was null, null is returned. */ /*! \fn type *QListIterator::operator+=( uint jump ) Sets the current item to the item \e jump positions after the current item, and returns a pointer to that item. If that item is beyond the last item or if the dictionary is empty, it sets the current item to null and returns null */ /*! \fn type *QListIterator::operator--() Prefix -- makes the preceding item current and returns the new current item. If the current iterator item was the first item in the list or if it was null, null is returned. */ /*! \fn type *QListIterator::operator-=( uint jump ) Returns the item \e jump positions before the current item, or null if it is beyond the first item. Makes this the current item. */ /*! \fn QListIterator& QListIterator::operator=( const QListIterator &it ) Assignment. Makes a copy of the iterator \a it and returns a reference to this iterator. */ /***************************************************************************** QStrList documentation *****************************************************************************/ //typedef QList QStrList /*! \class QStrList qstrlist.h \brief The QStrList class provides a doubly linked list of \c char*. \ingroup collection \ingroup tools This class is a QList\ instance (a list of char*). QStrList can make deep or shallow copies of the strings that are inserted. A deep copy means to allocate space for the string and then copy the string data into it. A shallow copy is just a copy of the pointer value and not the string data. The disadvantage with shallow copies is that since a pointer can only be deleted once, the program must put all strings in a central place and know when it is safe to delete them (i.e. when the strings are no longer referenced by other parts of the program). This can make the program more complex. The advantage of shallow copies is that shallow copies consume far less memory than deep copies. It is also much faster to copy a pointer (typically 4 or 8 bytes) than to copy string data. A QStrList that operates on deep copies will by default turn on auto-deletion (see setAutoDelete()). Thus, by default, QStrList will deallocate any string copies it allocates. The virtual compareItems() function is reimplemented and does a case sensitive string comparison. The inSort() function will insert strings in a sorted order. The QStrListIterator class is an iterator for QStrList. */ /*! \fn QStrList::QStrList( bool deepCopies ) Constructs an empty list of strings. Will make deep copies of all inserted strings if \e deepCopies is TRUE, or uses shallow copies if \e deepCopies is FALSE. */ /*! \fn QStrList::QStrList( const QStrList &list ) Constructs a copy of \e list. If \e list has deep copies, this list will also get deep copies. Only the pointers are copied (shallow copy) if the other list does not use deep copies. */ /*! \fn QStrList::~QStrList() Destroys the list. All strings are removed. */ /*! \fn QStrList& QStrList::operator=( const QStrList& list ) Assigns \e list to this list and returns a reference to this list. If \e list has deep copies, this list will also get deep copies. Only the pointers are copied (shallow copy) if the other list does not use deep copies. */ /***************************************************************************** QStrIList documentation *****************************************************************************/ /*! \class QStrIList qstrlist.h \brief The QStrIList class provides a doubly linked list of \c char* with case insensitive compare. \ingroup collection \ingroup tools This class is a QList\ instance (a list of char*). QStrIList is similar to QStrList except that it is case insensitive. The virtual compareItems() function is reimplemented and does a case insensitive string comparison. The inSort() function will insert strings in a sorted order. The QStrListIterator class is an iterator for QStrList. */ /*! \fn QStrIList::QStrIList( bool deepCopies ) Constructs a list of strings. Will make deep copies of all inserted strings if \e deepCopies is TRUE, or uses shallow copies if \e deepCopies is FALSE. */ /*! \fn QStrIList::~QStrIList() Destroys the list. All strings are removed. */ /***************************************************************************** QStrListIterator documentation *****************************************************************************/ /*! \class QStrListIterator qstrlist.h \brief The QStrListIterator class is an iterator for the QStrList and QStrIList classes. \ingroup tools This class is a QListIterator\ instance. It can traverse the strings in the QStrList and QStrIList classes. */