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1260 lines
36 KiB
1260 lines
36 KiB
/****************************************************************************
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**
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** QPtrList and QPtrListIterator class documentation
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**
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** Copyright (C) 1992-2008 Trolltech ASA. All rights reserved.
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**
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** This file is part of the TQt GUI Toolkit.
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**
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** This file may be used under the terms of the GNU General
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** Public License versions 2.0 or 3.0 as published by the Free
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** Software Foundation and appearing in the files LICENSE.GPL2
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** and LICENSE.GPL3 included in the packaging of this file.
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** Alternatively you may (at your option) use any later version
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** of the GNU General Public License if such license has been
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** publicly approved by Trolltech ASA (or its successors, if any)
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** and the KDE Free TQt Foundation.
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**
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** Please review the following information to ensure GNU General
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** Public Licensing requirements will be met:
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** http://trolltech.com/products/qt/licenses/licensing/opensource/.
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** If you are unsure which license is appropriate for your use, please
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** review the following information:
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** http://trolltech.com/products/qt/licenses/licensing/licensingoverview
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** or contact the sales department at sales@trolltech.com.
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**
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** This file may be used under the terms of the Q Public License as
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** defined by Trolltech ASA and appearing in the file LICENSE.QPL
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** included in the packaging of this file. Licensees holding valid Qt
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** Commercial licenses may use this file in accordance with the Qt
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** Commercial License Agreement provided with the Software.
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**
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** This file is provided "AS IS" with NO WARRANTY OF ANY KIND,
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** INCLUDING THE WARRANTIES OF DESIGN, MERCHANTABILITY AND FITNESS FOR
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** A PARTICULAR PURPOSE. Trolltech reserves all rights not granted
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** herein.
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**
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**********************************************************************/
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/*****************************************************************************
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QPtrList documentation
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*****************************************************************************/
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/*!
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\class QPtrList
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\brief The QPtrList class is a template class that provides a list.
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\ingroup collection
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\ingroup tools
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\important autoDelete setAutoDelete
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QValueList is an STL-compatible alternative to this class.
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Define a template instance QPtrList\<X\> to create a list that
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operates on pointers to X (X*).
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The list class is indexable and has a \link at() current
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index\endlink and a \link current() current item\endlink. The
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first item corresponds to index position 0. The current index is
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-1 if the current item is 0.
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Items are inserted with prepend(), insert() or append(). Items are
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removed with remove(), removeRef(), removeFirst() and
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removeLast(). You can search for an item using find(), findNext(),
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findRef() or findNextRef(). The list can be sorted with sort().
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You can count the number of occurrences of an item with contains()
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or containsRef(). You can get a pointer to the current item with
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current(), to an item at a particular index position in the list
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with at() or to the first or last item with getFirst() and
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getLast(). You can also iterate over the list with first(),
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last(), next() and prev() (which all update current()). The list's
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deletion property is set with setAutoDelete().
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\target example
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Example:
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\code
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class Employee
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{
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public:
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Employee() : sn( 0 ) { }
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Employee( const TQString& forename, const TQString& surname, int salary )
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: fn( forename ), sn( surname ), sal( salary )
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{ }
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void setSalary( int salary ) { sal = salary; }
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TQString forename() const { return fn; }
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TQString surname() const { return sn; }
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int salary() const { return sal; }
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private:
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TQString fn;
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TQString sn;
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int sal;
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};
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QPtrList<Employee> list;
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list.setAutoDelete( TRUE ); // the list owns the objects
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list.append( new Employee("John", "Doe", 50000) );
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list.append( new Employee("Jane", "Williams", 80000) );
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list.append( new Employee("Tom", "Jones", 60000) );
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Employee *employee;
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for ( employee = list.first(); employee; employee = list.next() )
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cout << employee->surname().latin1() << ", " <<
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employee->forename().latin1() << " earns " <<
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employee->salary() << endl;
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cout << endl;
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// very inefficient for big lists
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for ( uint i = 0; i < list.count(); ++i )
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if ( list.at(i) )
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cout << list.at( i )->surname().latin1() << endl;
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\endcode
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The output is
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\code
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Doe, John earns 50000
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Williams, Jane earns 80000
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Jones, Tom earns 60000
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Doe
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Williams
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Jones
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\endcode
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QPtrList has several member functions for traversing the list, but
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using a QPtrListIterator can be more practical. Multiple list
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iterators may traverse the same list, independently of each other
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and of the current list item.
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In the example above we make the call setAutoDelete(TRUE).
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Enabling auto-deletion tells the list to delete items that are
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removed. The default is to not delete items when they are removed
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but this would cause a memory leak in the example because there
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are no other references to the list items.
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When inserting an item into a list only the pointer is copied, not
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the item itself, i.e. a shallow copy. It is possible to make the
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list copy all of the item's data (deep copy) when an item is
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inserted. insert(), inSort() and append() call the virtual
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function QPtrCollection::newItem() for the item to be inserted.
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Inherit a list and reimplement newItem() to have deep copies.
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When removing an item from a list, the virtual function
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QPtrCollection::deleteItem() is called. QPtrList's default
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implementation is to delete the item if auto-deletion is enabled.
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The virtual function compareItems() can be reimplemented to
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compare two list items. This function is called from all list
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functions that need to compare list items, for instance
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remove(const type*). If you only want to deal with pointers, there
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are functions that compare pointers instead, for instance
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removeRef(const type*). These functions are somewhat faster than
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those that call compareItems().
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List items are stored as \c void* in an internal QLNode, which
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also holds pointers to the next and previous list items. The
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functions currentNode(), removeNode(), and takeNode() operate
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directly on the QLNode, but they should be used with care. The
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data component of the node is available through QLNode::getData().
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The QStrList class defined in \l ntqstrlist.h is a list of \c char*.
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It reimplements newItem(), deleteItem() and compareItems(). (But
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see QStringList for a list of Unicode QStrings.)
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\sa QPtrListIterator
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*/
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/*!
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\fn QPtrList::QPtrList()
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Constructs an empty list.
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*/
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/*!
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\fn QPtrList::QPtrList( const QPtrList<type> &list )
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Constructs a copy of \a list.
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Each item in \a list is \link append() appended\endlink to this
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list. Only the pointers are copied (shallow copy).
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*/
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/*!
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\fn QPtrList::~QPtrList()
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Removes all items from the list and destroys the list.
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All list iterators that access this list will be reset.
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\sa setAutoDelete()
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*/
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/*!
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\fn QPtrList<type> &QPtrList::operator=(const QPtrList<type> &list)
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Assigns \a list to this list and returns a reference to this list.
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This list is first cleared and then each item in \a list is \link
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append() appended\endlink to this list. Only the pointers are
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copied (shallow copy) unless newItem() has been reimplemented.
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*/
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/*!
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\fn bool QPtrList::operator==(const QPtrList<type> &list ) const
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Compares this list with \a list. Returns TRUE if the lists contain
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the same data; otherwise returns FALSE.
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*/
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/*!
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\fn uint QPtrList::count() const
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Returns the number of items in the list.
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\sa isEmpty()
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*/
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/*!
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\fn bool QPtrList::operator!=(const QPtrList<type> &list ) const
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Compares this list with \a list. Returns TRUE if the lists contain
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different data; otherwise returns FALSE.
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*/
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/*!
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\fn void QPtrList::sort()
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Sorts the list by the result of the virtual compareItems()
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function.
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The heap sort algorithm is used for sorting. It sorts n items with
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O(n*log n) comparisons. This is the asymptotic optimal solution of
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the sorting problem.
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If the items in your list support operator<() and operator==(),
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you might be better off with QSortedList because it implements the
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compareItems() function for you using these two operators.
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\sa inSort()
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*/
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/*!
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\fn bool QPtrList::isEmpty() const
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Returns TRUE if the list is empty; otherwise returns FALSE.
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\sa count()
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*/
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/*!
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\fn bool QPtrList::insert( uint index, const type *item )
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Inserts the \a item at position \a index in the list.
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Returns TRUE if successful, i.e. if \a index is in range;
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otherwise returns FALSE. The valid range is 0 to count()
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(inclusively). The item is appended if \a index == count().
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The inserted item becomes the current list item.
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\a item must not be 0.
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\sa append(), current(), replace()
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*/
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/*!
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\fn bool QPtrList::replace( uint index, const type *item )
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Replaces the item at position \a index with the new \a item.
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Returns TRUE if successful, i.e. \a index is in the range 0 to
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count()-1.
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\sa append(), current(), insert()
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*/
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/*!
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\fn void QPtrList::inSort( const type *item )
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Inserts the \a item at its sorted position in the list.
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The sort order depends on the virtual compareItems() function. All
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items must be inserted with inSort() to maintain the sorting
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order.
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The inserted item becomes the current list item.
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\a item must not be 0.
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\warning Using inSort() is slow. An alternative, especially if you
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have lots of items, is to simply append() or insert() them and
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then use sort(). inSort() takes up to O(n) compares. That means
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inserting n items in your list will need O(n^2) compares whereas
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sort() only needs O(n*log n) for the same task. So use inSort()
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only if you already have a presorted list and want to insert just
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a few additional items.
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\sa insert(), compareItems(), current(), sort()
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*/
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/*!
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\fn void QPtrList::append( const type *item )
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Inserts the \a item at the end of the list.
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The inserted item becomes the current list item. This is
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equivalent to \c{insert( count(), item )}.
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\a item must not be 0.
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\sa insert(), current(), prepend()
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*/
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/*!
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\fn void QPtrList::prepend( const type *item )
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Inserts the \a item at the start of the list.
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The inserted item becomes the current list item. This is
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equivalent to \c{insert( 0, item )}.
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\a item must not be 0.
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\sa append(), insert(), current()
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*/
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/*!
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\fn bool QPtrList::remove( uint index )
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Removes the item at position \a index in the list.
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Returns TRUE if successful, i.e. if \a index is in range;
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otherwise returns FALSE. The valid range is \c{0..(count() - 1)}
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inclusive.
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The removed item is deleted if \link setAutoDelete()
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auto-deletion\endlink is enabled.
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The item after the removed item becomes the new current list item
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if the removed item is not the last item in the list. If the last
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item is removed, the new last item becomes the current item.
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All list iterators that refer to the removed item will be set to
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point to the new current item.
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\sa take(), clear(), setAutoDelete(), current() removeRef()
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*/
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/*!
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\fn bool QPtrList::remove()
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\overload
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Removes the current list item.
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Returns TRUE if successful, i.e. if the current item isn't 0;
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otherwise returns FALSE.
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The removed item is deleted if \link setAutoDelete()
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auto-deletion\endlink is enabled.
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The item after the removed item becomes the new current list item
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if the removed item is not the last item in the list. If the last
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item is removed, the new last item becomes the current item. The
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current item is set to 0 if the list becomes empty.
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All list iterators that refer to the removed item will be set to
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point to the new current item.
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\sa take(), clear(), setAutoDelete(), current() removeRef()
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*/
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/*!
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\fn bool QPtrList::remove( const type *item )
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\overload
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Removes the first occurrence of \a item from the list.
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Returns TRUE if successful, i.e. if \a item is in the list;
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otherwise returns FALSE.
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The removed item is deleted if \link setAutoDelete()
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auto-deletion\endlink is enabled.
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The compareItems() function is called when searching for the item
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in the list. If compareItems() is not reimplemented, it is more
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efficient to call removeRef().
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If \a item is NULL then the current item is removed from the list.
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The item after the removed item becomes the new current list item
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if the removed item is not the last item in the list. If the last
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item is removed, the new last item becomes the current item. The
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current item is set to 0 if the list becomes empty.
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All list iterators that refer to the removed item will be set to
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point to the new current item.
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\sa removeRef(), take(), clear(), setAutoDelete(), compareItems(),
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current()
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*/
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/*!
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\fn bool QPtrList::removeRef( const type *item )
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Removes the first occurrence of \a item from the list.
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Returns TRUE if successful, i.e. if \a item is in the list;
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otherwise returns FALSE.
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The removed item is deleted if \link setAutoDelete()
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auto-deletion\endlink is enabled.
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Equivalent to:
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\code
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if ( list.findRef( item ) != -1 )
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list.remove();
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\endcode
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The item after the removed item becomes the new current list item
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if the removed item is not the last item in the list. If the last
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item is removed, the new last item becomes the current item. The
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current item is set to 0 if the list becomes empty.
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All list iterators that refer to the removed item will be set to
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point to the new current item.
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\sa remove(), clear(), setAutoDelete(), current()
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*/
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/*!
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\fn void QPtrList::removeNode( QLNode *node )
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Removes the \a node from the list.
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This node must exist in the list, otherwise the program may crash.
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The removed item is deleted if \link setAutoDelete()
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auto-deletion\endlink is enabled.
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The first item in the list will become the new current list item.
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The current item is set to 0 if the list becomes empty.
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All list iterators that refer to the removed item will be set to
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point to the item succeeding this item or to the preceding item if
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the removed item was the last item.
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\warning Do not call this function unless you are an expert.
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\sa takeNode(), currentNode() remove() removeRef()
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*/
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|
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/*!
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\fn bool QPtrList::removeFirst()
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Removes the first item from the list. Returns TRUE if successful,
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i.e. if the list isn't empty; otherwise returns FALSE.
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The removed item is deleted if \link setAutoDelete()
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auto-deletion\endlink is enabled.
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The first item in the list becomes the new current list item. The
|
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current item is set to 0 if the list becomes empty.
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All list iterators that refer to the removed item will be set to
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point to the new current item.
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\sa removeLast(), setAutoDelete(), current() remove()
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*/
|
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|
|
/*!
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\fn bool QPtrList::removeLast()
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Removes the last item from the list. Returns TRUE if successful,
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i.e. if the list isn't empty; otherwise returns FALSE.
|
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The removed item is deleted if \link setAutoDelete()
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auto-deletion\endlink is enabled.
|
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The last item in the list becomes the new current list item. The
|
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current item is set to 0 if the list becomes empty.
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|
|
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All list iterators that refer to the removed item will be set to
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point to the new current item.
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\sa removeFirst(), setAutoDelete(), current()
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|
*/
|
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|
|
/*!
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|
\fn type *QPtrList::take( uint index )
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Takes the item at position \a index out of the list without
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deleting it (even if \link setAutoDelete() auto-deletion\endlink
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is enabled).
|
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Returns a pointer to the item taken out of the list, or 0 if the
|
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index is out of range. The valid range is \c{0..(count() - 1)}
|
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inclusive.
|
|
|
|
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. The
|
|
current item is set to 0 if the list becomes empty.
|
|
|
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All list iterators that refer to the taken item will be set to
|
|
point to the new current item.
|
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\sa remove(), clear(), current()
|
|
*/
|
|
|
|
/*!
|
|
\fn type *QPtrList::take()
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\overload
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Takes the current item out of the list without deleting it (even
|
|
if \link setAutoDelete() auto-deletion\endlink is enabled).
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Returns a pointer to the item taken out of the list, or 0 if
|
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the current item is 0.
|
|
|
|
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. The
|
|
current item is set to 0 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 *QPtrList::takeNode( QLNode *node )
|
|
|
|
Takes the \a node out of the list without deleting its item (even
|
|
if \link 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 to 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 QPtrList::clear()
|
|
|
|
Removes all items from the list.
|
|
|
|
The removed items are deleted if \link setAutoDelete()
|
|
auto-deletion\endlink is enabled.
|
|
|
|
All list iterators that access this list will be reset.
|
|
|
|
\sa remove(), take(), setAutoDelete()
|
|
*/
|
|
|
|
/*!
|
|
\fn int QPtrList::find( const type *item )
|
|
|
|
Finds the first occurrence of \a 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 0, 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 QPtrList::findNext( const type *item )
|
|
|
|
Finds the next occurrence of \a 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 0, 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 QPtrList::findRef( const type *item )
|
|
|
|
Finds the first occurrence of \a 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 0, the current
|
|
index to -1, and returns -1.
|
|
|
|
Calling this function is much faster than find() because find()
|
|
compares \a item with each list item using compareItems(), whereas
|
|
this function only compares the pointers.
|
|
|
|
\sa findNextRef(), find(), current()
|
|
*/
|
|
|
|
/*!
|
|
\fn int QPtrList::findNextRef( const type *item )
|
|
|
|
Finds the next occurrence of \a 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 0, the current
|
|
index to -1, and returns -1.
|
|
|
|
Calling this function is much faster than findNext() because
|
|
findNext() compares \a item with each list item using
|
|
compareItems(), whereas this function only compares the pointers.
|
|
|
|
\sa findRef(), findNext(), current()
|
|
*/
|
|
|
|
/*!
|
|
\fn uint QPtrList::contains( const type *item ) const
|
|
|
|
Returns the number of occurrences of \a item in the list.
|
|
|
|
The compareItems() function is called when looking for the \a item
|
|
in the list. If compareItems() is not reimplemented, it is more
|
|
efficient to call containsRef().
|
|
|
|
This function does not affect the current list item.
|
|
|
|
\sa containsRef(), compareItems()
|
|
*/
|
|
|
|
/*!
|
|
\fn uint QPtrList::containsRef( const type *item ) const
|
|
|
|
Returns the number of occurrences of \a item in the list.
|
|
|
|
Calling this function is much faster than contains() because
|
|
contains() compares \a item with each list item using
|
|
compareItems(), whereas his function only compares the pointers.
|
|
|
|
This function does not affect the current list item.
|
|
|
|
\sa contains()
|
|
*/
|
|
|
|
/*!
|
|
\fn type *QPtrList::at( uint index )
|
|
|
|
Returns a pointer to the item at position \a index in the list, or
|
|
0 if the index is out of range.
|
|
|
|
Sets the current list item to this item if \a index is valid. The
|
|
valid range is \c{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 \a
|
|
index.
|
|
|
|
\sa current()
|
|
*/
|
|
|
|
/*!
|
|
\fn int QPtrList::at() const
|
|
|
|
\overload
|
|
|
|
Returns the index of the current list item. The returned value is
|
|
-1 if the current item is 0.
|
|
|
|
\sa current()
|
|
*/
|
|
|
|
/*!
|
|
\fn type *QPtrList::current() const
|
|
|
|
Returns a pointer to the current list item. The current item may
|
|
be 0 (implies that the current index is -1).
|
|
|
|
\sa at()
|
|
*/
|
|
|
|
/*!
|
|
\fn QLNode *QPtrList::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 *QPtrList::getFirst() const
|
|
|
|
Returns a pointer to the first item in the list, or 0 if the list
|
|
is empty.
|
|
|
|
This function does not affect the current list item.
|
|
|
|
\sa first(), getLast()
|
|
*/
|
|
|
|
/*!
|
|
\fn type *QPtrList::getLast() const
|
|
|
|
Returns a pointer to the last item in the list, or 0 if the list
|
|
is empty.
|
|
|
|
This function does not affect the current list item.
|
|
|
|
\sa last(), getFirst()
|
|
*/
|
|
|
|
/*!
|
|
\fn type *QPtrList::first()
|
|
|
|
Returns a pointer to the first item in the list and makes this the
|
|
current list item; returns 0 if the list is empty.
|
|
|
|
\sa getFirst(), last(), next(), prev(), current()
|
|
*/
|
|
|
|
/*!
|
|
\fn type *QPtrList::last()
|
|
|
|
Returns a pointer to the last item in the list and makes this the
|
|
current list item; returns 0 if the list is empty.
|
|
|
|
\sa getLast(), first(), next(), prev(), current()
|
|
*/
|
|
|
|
/*!
|
|
\fn type *QPtrList::next()
|
|
|
|
Returns a pointer to the item succeeding the current item. Returns
|
|
0 if the current item is 0 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
|
|
0. If the current item was 0, this function does nothing.
|
|
|
|
\sa first(), last(), prev(), current()
|
|
*/
|
|
|
|
/*!
|
|
\fn type *QPtrList::prev()
|
|
|
|
Returns a pointer to the item preceding the current item. Returns
|
|
0 if the current item is 0 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
|
|
0. If the current item was 0, this function does nothing.
|
|
|
|
\sa first(), last(), next(), current()
|
|
*/
|
|
|
|
/*!
|
|
\fn void QPtrList::toVector( QGVector *vec ) const
|
|
|
|
Stores all list items in the vector \a vec.
|
|
|
|
The vector must be of the same item type, otherwise the result
|
|
will be undefined.
|
|
*/
|
|
|
|
/*!
|
|
\enum QPtrList::iterator
|
|
|
|
\internal
|
|
*/
|
|
|
|
/*!
|
|
\enum QPtrList::Iterator
|
|
|
|
\internal
|
|
*/
|
|
|
|
/*!
|
|
\enum QPtrList::ConstIterator
|
|
|
|
\internal
|
|
*/
|
|
|
|
/*!
|
|
\enum QPtrList::const_iterator
|
|
|
|
\internal
|
|
*/
|
|
|
|
/*!
|
|
\fn QPtrList::constBegin() const
|
|
|
|
\internal
|
|
*/
|
|
|
|
/*!
|
|
\fn QPtrList::constEnd() const
|
|
|
|
\internal
|
|
*/
|
|
|
|
/*!
|
|
\fn QPtrList::erase(Iterator)
|
|
|
|
\internal
|
|
*/
|
|
|
|
|
|
/*****************************************************************************
|
|
QPtrListIterator documentation
|
|
*****************************************************************************/
|
|
|
|
/*!
|
|
\class QPtrListIterator
|
|
\brief The QPtrListIterator class provides an iterator for
|
|
QPtrList collections.
|
|
|
|
\ingroup collection
|
|
\ingroup tools
|
|
|
|
Define a template instance QPtrListIterator\<X\> to create a list
|
|
iterator that operates on QPtrList\<X\> (list of X*).
|
|
|
|
The following example is similar to the \link
|
|
ntqptrlist.html#example example in the QPtrList class documentation
|
|
\endlink, but it uses QPtrListIterator. The class Employee is
|
|
defined there.
|
|
|
|
\code
|
|
QPtrList<Employee> list;
|
|
|
|
list.append( new Employee("John", "Doe", 50000) );
|
|
list.append( new Employee("Jane", "Williams", 80000) );
|
|
list.append( new Employee("Tom", "Jones", 60000) );
|
|
|
|
QPtrListIterator<Employee> it( list );
|
|
Employee *employee;
|
|
while ( (employee = it.current()) != 0 ) {
|
|
++it;
|
|
cout << employee->surname().latin1() << ", " <<
|
|
employee->forename().latin1() << " earns " <<
|
|
employee->salary() << endl;
|
|
}
|
|
\endcode
|
|
|
|
The output is
|
|
\code
|
|
Doe, John earns 50000
|
|
Williams, Jane earns 80000
|
|
Jones, Tom earns 60000
|
|
\endcode
|
|
|
|
Using a list iterator is a more robust way of traversing the list
|
|
than using the QPtrList member functions \link QPtrList::first()
|
|
first\endlink(), \link QPtrList::next() next\endlink(), \link
|
|
QPtrList::current() current\endlink(), etc., as many iterators can
|
|
traverse the same list independently.
|
|
|
|
An iterator has its own current list item and can get the next and
|
|
previous list items. It doesn't modify the list in any way.
|
|
|
|
When an item is removed from the list, all iterators that point to
|
|
that item are updated to point to QPtrList::current() instead to
|
|
avoid dangling references.
|
|
|
|
\sa QPtrList
|
|
*/
|
|
|
|
/*!
|
|
\fn QPtrListIterator::QPtrListIterator( const QPtrList<type> &list )
|
|
|
|
Constructs an iterator for \a list. The current iterator item is
|
|
set to point on the first item in the \a list.
|
|
*/
|
|
|
|
/*!
|
|
\fn QPtrListIterator::~QPtrListIterator()
|
|
|
|
Destroys the iterator.
|
|
*/
|
|
|
|
/*!
|
|
\fn uint QPtrListIterator::count() const
|
|
|
|
Returns the number of items in the list this iterator operates on.
|
|
|
|
\sa isEmpty()
|
|
*/
|
|
|
|
/*!
|
|
\fn bool QPtrListIterator::isEmpty() const
|
|
|
|
Returns TRUE if the list is empty; otherwise returns FALSE.
|
|
|
|
\sa count()
|
|
*/
|
|
|
|
/*!
|
|
\fn bool QPtrListIterator::atFirst() const
|
|
|
|
Returns TRUE if the current iterator item is the first list item;
|
|
otherwise returns FALSE.
|
|
|
|
\sa toFirst(), atLast()
|
|
*/
|
|
|
|
/*!
|
|
\fn bool QPtrListIterator::atLast() const
|
|
|
|
Returns TRUE if the current iterator item is the last list item;
|
|
otherwise returns FALSE.
|
|
|
|
\sa toLast(), atFirst()
|
|
*/
|
|
|
|
/*!
|
|
\fn type *QPtrListIterator::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 0 and
|
|
returns 0 if the list is empty.
|
|
|
|
\sa toLast(), atFirst()
|
|
*/
|
|
|
|
/*!
|
|
\fn type *QPtrListIterator::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 0 and
|
|
returns 0 if the list is empty.
|
|
|
|
\sa toFirst(), atLast()
|
|
*/
|
|
|
|
/*!
|
|
\fn QPtrListIterator::operator type *() const
|
|
|
|
Cast operator. Returns a pointer to the current iterator item.
|
|
Same as current().
|
|
*/
|
|
|
|
/*!
|
|
\fn type *QPtrListIterator::operator*()
|
|
|
|
Asterisk operator. Returns a pointer to the current iterator item.
|
|
Same as current().
|
|
*/
|
|
|
|
/*!
|
|
\fn type *QPtrListIterator::current() const
|
|
|
|
Returns a pointer to the current iterator item. If the iterator is
|
|
positioned before the first item in the list or after the last
|
|
item in the list, 0 is returned.
|
|
*/
|
|
|
|
/*!
|
|
\fn type *QPtrListIterator::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 0, 0 is returned.
|
|
*/
|
|
|
|
/*!
|
|
\fn type *QPtrListIterator::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 0, 0 is returned.
|
|
*/
|
|
|
|
/*!
|
|
\fn type *QPtrListIterator::operator+=( uint jump )
|
|
|
|
Sets the current item to the item \a jump positions after the
|
|
current item and returns a pointer to that item.
|
|
|
|
If that item is beyond the last item or if the list is empty, it
|
|
sets the current item to 0 and returns 0
|
|
*/
|
|
|
|
/*!
|
|
\fn type *QPtrListIterator::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 0, 0 is returned.
|
|
*/
|
|
|
|
/*!
|
|
\fn type *QPtrListIterator::operator-=( uint jump )
|
|
|
|
Returns the item \a jump positions before the current item or 0
|
|
if it is beyond the first item. Makes this the current item.
|
|
*/
|
|
|
|
/*!
|
|
\fn QPtrListIterator<type>& QPtrListIterator::operator=( const QPtrListIterator<type> &it )
|
|
|
|
Assignment. Makes a copy of the iterator \a it and returns a
|
|
reference to this iterator.
|
|
*/
|
|
|
|
|
|
/*****************************************************************************
|
|
QStrList documentation
|
|
*****************************************************************************/
|
|
|
|
/*!
|
|
\class QStrList ntqstrlist.h
|
|
\brief The QStrList class provides a doubly-linked list of char*.
|
|
|
|
\ingroup collection
|
|
\ingroup tools
|
|
\ingroup text
|
|
|
|
If you want a string list of \l{TQString}s use QStringList.
|
|
|
|
This class is a QPtrList\<char\> instance (a list of char*).
|
|
|
|
QStrList can make deep or shallow copies of the strings that are
|
|
inserted.
|
|
|
|
A deep copy means that memory is allocated for the string and then
|
|
the string data is copied into that memory. A shallow copy is just
|
|
a copy of the pointer value and not of the string data itself.
|
|
|
|
The disadvantage of shallow copies is that because a pointer can
|
|
be deleted only 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 they 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 sorted order. In general it is fastest to insert
|
|
the strings as they come and sort() at the end; inSort() is useful
|
|
when you just have to add a few extra strings to an already sorted
|
|
list.
|
|
|
|
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 \a deepCopies is TRUE, or use shallow copies
|
|
if \a deepCopies is FALSE.
|
|
*/
|
|
|
|
/*!
|
|
\fn QStrList::QStrList( const QStrList &list )
|
|
|
|
Constructs a copy of \a list.
|
|
|
|
If \a 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 \a list to this list and returns a reference to this list.
|
|
|
|
If \a 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 ntqstrlist.h
|
|
\brief The QStrIList class provides a doubly-linked list of char*
|
|
with case-insensitive comparison.
|
|
|
|
\ingroup collection
|
|
\ingroup tools
|
|
|
|
This class is a QPtrList\<char\> instance (a list of char*).
|
|
|
|
QStrIList is identical to QStrList except that the virtual
|
|
compareItems() function is reimplemented to compare strings
|
|
case-insensitively. The inSort() function inserts strings in a
|
|
sorted order. In general it is fastest to insert the strings as
|
|
they come and sort() at the end; inSort() is useful when you just
|
|
have to add a few extra strings to an already sorted list.
|
|
|
|
The QStrListIterator class works for QStrIList.
|
|
|
|
\sa QStringList
|
|
*/
|
|
|
|
/*!
|
|
\fn QStrIList::QStrIList( bool deepCopies )
|
|
|
|
Constructs a list of strings. Will make deep copies of all
|
|
inserted strings if \a deepCopies is TRUE, or use shallow copies
|
|
if \a deepCopies is FALSE.
|
|
*/
|
|
|
|
/*!
|
|
\fn QStrIList::~QStrIList()
|
|
|
|
Destroys the list. All strings are removed.
|
|
*/
|
|
|
|
/*!
|
|
\fn int QPtrList::compareItems( QPtrCollection::Item item1,
|
|
QPtrCollection::Item item2 )
|
|
|
|
This virtual function compares two list items.
|
|
|
|
Returns:
|
|
\list
|
|
\i zero if \a item1 == \a item2
|
|
\i nonzero if \a item1 != \a item2
|
|
\endlist
|
|
|
|
This function returns \e int rather than \e bool so that
|
|
reimplementations can return three values and use it to sort by:
|
|
|
|
\list
|
|
\i 0 if \a item1 == \a item2
|
|
\i \> 0 (positive integer) if \a item1 \> \a item2
|
|
\i \< 0 (negative integer) if \a item1 \< \a item2
|
|
\endlist
|
|
|
|
inSort() requires that compareItems() is implemented as described
|
|
here.
|
|
|
|
This function should not modify the list because some const
|
|
functions call compareItems().
|
|
|
|
The default implementation compares the pointers.
|
|
*/
|
|
|
|
/*!
|
|
\fn QDataStream& QPtrList::read( QDataStream& s,
|
|
QPtrCollection::Item& item )
|
|
|
|
Reads a list item from the stream \a s and returns a reference to
|
|
the stream.
|
|
|
|
The default implementation sets \a item to 0.
|
|
|
|
\sa write()
|
|
*/
|
|
|
|
/*!
|
|
\fn QDataStream& QPtrList::write( QDataStream& s,
|
|
QPtrCollection::Item item ) const
|
|
|
|
Writes a list item, \a item to the stream \a s and returns a
|
|
reference to the stream.
|
|
|
|
The default implementation does nothing.
|
|
|
|
\sa read()
|
|
*/
|
|
|
|
/*! \fn iterator QPtrList::begin()
|
|
\internal
|
|
*/
|
|
/*! \fn const_iterator QPtrList::begin() const
|
|
\internal
|
|
*/
|
|
/*! \fn iterator QPtrList::end()
|
|
\internal
|
|
*/
|
|
/*! \fn const_iterator QPtrList::end() const
|
|
\internal
|
|
*/
|
|
|
|
/*****************************************************************************
|
|
QStrListIterator documentation
|
|
*****************************************************************************/
|
|
|
|
/*!
|
|
\class QStrListIterator ntqstrlist.h
|
|
\brief The QStrListIterator class is an iterator for the QStrList
|
|
and QStrIList classes.
|
|
|
|
\ingroup tools
|
|
|
|
This class is a QPtrListIterator\<char\> instance. It can traverse
|
|
the strings in the QStrList and QStrIList classes.
|
|
*/
|
|
|
|
|
|
/*****************************************************************************
|
|
QPtrListAutoDelete documentation
|
|
*****************************************************************************/
|
|
/*
|
|
\class QPtrListAutoDelete
|
|
\brief The QPtrListAutoDelete class is a template class that provides a list that auto-deletes its data.
|
|
|
|
\ingroup collection
|
|
\ingroup tools
|
|
|
|
A QPtrListAutoDelete is identical to a QPtrList with
|
|
setAutoDelete(TRUE).
|
|
*/
|