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tqt3/doc/qintdict.doc

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/****************************************************************************
**
** QIntDict and QIntDictIterator class documentation
**
** Copyright (C) 1992-2008 Trolltech ASA. All rights reserved.
**
** This file is part of the Qt GUI Toolkit.
**
** This file may be used under the terms of the GNU General
** Public License versions 2.0 or 3.0 as published by the Free
** Software Foundation and appearing in the files LICENSE.GPL2
** and LICENSE.GPL3 included in the packaging of this file.
** Alternatively you may (at your option) use any later version
** of the GNU General Public License if such license has been
** publicly approved by Trolltech ASA (or its successors, if any)
** and the KDE Free Qt Foundation.
**
** Please review the following information to ensure GNU General
** Public Licensing requirements will be met:
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** If you are unsure which license is appropriate for your use, please
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**
** This file may be used under the terms of the Q Public License as
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** Commercial 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 WARRANTIES OF DESIGN, MERCHANTABILITY AND FITNESS FOR
** A PARTICULAR PURPOSE. Trolltech reserves all rights not granted
** herein.
**
**********************************************************************/
/*****************************************************************************
QIntDict documentation
*****************************************************************************/
/*!
\class QIntDict ntqintdict.h
\brief The QIntDict class is a template class that provides a dictionary based on long keys.
\ingroup collection
\ingroup tools
\important autoDelete setAutoDelete
QMap is an STL-compatible alternative to this class.
QIntDict is implemented as a template class. Define a template
instance QIntDict\<X\> to create a dictionary that operates on
pointers to X (X*).
A dictionary is a collection of key-value pairs. The key is an \c
long used for insertion, removal and lookup. The value is a
pointer. Dictionaries provide very fast insertion and lookup.
Example:
\code
QIntDict<QLineEdit> fields; // long int keys, QLineEdit* values
for ( int i = 0; i < 3; i++ )
fields.insert( i, new QLineEdit( this ) );
fields[0]->setText( "Homer" );
fields[1]->setText( "Simpson" );
fields[2]->setText( "45" );
QIntDictIterator<QLineEdit> it( fields );
for ( ; it.current(); ++it )
cout << it.currentKey() << ": " << it.current()->text() << endl;
for ( int i = 0; i < 3; i++ )
cout << fields[i]->text() << " "; // Prints "Homer Simpson 45"
cout << endl;
fields.remove( 1 ); // Does not delete the line edit
for ( int i = 0; i < 3; i++ )
if ( fields[i] )
cout << fields[i]->text() << " "; // Prints "Homer 45"
\endcode
See QDict for full details, including the choice of dictionary
size, and how deletions are handled.
\sa QIntDictIterator, QDict, QAsciiDict, QPtrDict,
\link collection.html Collection Classes\endlink
*/
/*!
\fn QIntDict::QIntDict( int size )
Constructs a dictionary using an internal hash array of size \a
size.
Setting \a size to a suitably large prime number (equal to or
greater than the expected number of entries) makes the hash
distribution better which leads to faster lookup.
*/
/*!
\fn QIntDict::QIntDict( const QIntDict<type> &dict )
Constructs a copy of \a dict.
Each item in \a dict is inserted into this dictionary. Only the
pointers are copied (shallow copy).
*/
/*!
\fn QIntDict::~QIntDict()
Removes all items from the dictionary and destroys it.
All iterators that access this dictionary will be reset.
\sa setAutoDelete()
*/
/*!
\fn QIntDict<type> &QIntDict::operator=(const QIntDict<type> &dict)
Assigns \a dict to this dictionary and returns a reference to this
dictionary.
This dictionary is first cleared and then each item in \a dict is
inserted into this dictionary. Only the pointers are copied
(shallow copy), unless newItem() has been reimplemented.
*/
/*!
\fn uint QIntDict::count() const
Returns the number of items in the dictionary.
\sa isEmpty()
*/
/*!
\fn uint QIntDict::size() const
Returns the size of the internal hash array (as specified in the
constructor).
\sa count()
*/
/*!
\fn void QIntDict::resize( uint newsize )
Changes the size of the hashtable to \a newsize. The contents of
the dictionary are preserved, but all iterators on the dictionary
become invalid.
*/
/*!
\fn bool QIntDict::isEmpty() const
Returns TRUE if the dictionary is empty; otherwise returns FALSE.
\sa count()
*/
/*!
\fn void QIntDict::insert( long key, const type *item )
Insert item \a item into the dictionary using key \a key.
Multiple items can have the same key, in which case only the last
item will be accessible using \l operator[]().
\a item may not be 0.
\sa replace()
*/
/*!
\fn void QIntDict::replace( long key, const type *item )
If the dictionary has key \a key, this key's item is replaced with
\a item. If the dictionary doesn't contain key \a key, \a item is
inserted into the dictionary using key \a key.
\a item may not be 0.
Equivalent to:
\code
QIntDict<char> dict;
// ...
if ( dict.find(key) )
dict.remove( key );
dict.insert( key, item );
\endcode
If there are two or more items with equal keys, then the most
recently inserted item will be replaced.
\sa insert()
*/
/*!
\fn bool QIntDict::remove( long key )
Removes the item associated with \a key from the dictionary.
Returns TRUE if successful, i.e. if the \a key is in the
dictionary; otherwise returns FALSE.
If there are two or more items with equal keys, then the most
recently inserted item will be removed.
The removed item is deleted if \link
QPtrCollection::setAutoDelete() auto-deletion\endlink is enabled.
All dictionary iterators that refer to the removed item will be
set to point to the next item in the dictionary's traversal
order.
\sa take(), clear(), setAutoDelete()
*/
/*!
\fn type *QIntDict::take( long key )
Takes the item associated with \a key out of the dictionary
without deleting it (even if \link QPtrCollection::setAutoDelete()
auto-deletion\endlink is enabled).
If there are two or more items with equal keys, then the most
recently inserted item will be taken.
Returns a pointer to the item taken out, or 0 if the key does not
exist in the dictionary.
All dictionary iterators that refer to the taken item will be set
to point to the next item in the dictionary's traversing order.
\sa remove(), clear(), setAutoDelete()
*/
/*!
\fn void QIntDict::clear()
Removes all items from the dictionary.
The removed items are deleted if \link
QPtrCollection::setAutoDelete() auto-deletion\endlink is enabled.
All dictionary iterators that access this dictionary will be reset.
\sa remove(), take(), setAutoDelete()
*/
/*!
\fn type *QIntDict::find( long key ) const
Returns the item associated with \a key, or 0 if the key does not
exist in the dictionary.
If there are two or more items with equal keys, then the most
recently inserted item will be found.
Equivalent to operator[].
\sa operator[]()
*/
/*!
\fn type *QIntDict::operator[]( long key ) const
Returns the item associated with \a key, or 0 if the key does not
exist in the dictionary.
If there are two or more items with equal keys, then the most
recently inserted item will be found.
Equivalent to the find() function.
\sa find()
*/
/*!
\fn void QIntDict::statistics() const
Debugging-only function that prints out the dictionary
distribution using qDebug().
*/
/*!
\fn QDataStream& QIntDict::read( QDataStream &s, QPtrCollection::Item &item )
Reads a dictionary 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& QIntDict::write( QDataStream &s, QPtrCollection::Item ) const
Writes a dictionary item to the stream \a s and returns a
reference to the stream.
\sa read()
*/
/*****************************************************************************
QIntDictIterator documentation
*****************************************************************************/
/*!
\class QIntDictIterator ntqintdict.h
\brief The QIntDictIterator class provides an iterator for QIntDict collections.
\ingroup collection
\ingroup tools
QIntDictIterator is implemented as a template class. Define a
template instance QIntDictIterator\<X\> to create a dictionary
iterator that operates on QIntDict\<X\> (dictionary of X*).
Example:
\code
QIntDict<QLineEdit> fields;
for ( int i = 0; i < 3; i++ )
fields.insert( i, new QLineEdit( this ) );
fields[0]->setText( "Homer" );
fields[1]->setText( "Simpson" );
fields[2]->setText( "45" );
QIntDictIterator<QLineEdit> it( fields );
for ( ; it.current(); ++it )
cout << it.currentKey() << ": " << it.current()->text() << endl;
// Output (random order):
// 0: Homer
// 1: Simpson
// 2: 45
\endcode
Note that the traversal order is arbitrary; you are not guaranteed the
order shown above.
Multiple iterators may independently traverse the same dictionary.
A QIntDict knows about all the iterators that are operating on the
dictionary. When an item is removed from the dictionary, QIntDict
updates all iterators that refer the removed item to point to the
next item in the traversal order.
\sa QIntDict
*/
/*!
\fn QIntDictIterator::QIntDictIterator( const QIntDict<type> &dict )
Constructs an iterator for \a dict. The current iterator item is
set to point to the 'first' item in the \a dict. The first item
refers to the first item in the dictionary's arbitrary internal
ordering.
*/
/*!
\fn QIntDictIterator::~QIntDictIterator()
Destroys the iterator.
*/
/*!
\fn uint QIntDictIterator::count() const
Returns the number of items in the dictionary this iterator
operates over.
\sa isEmpty()
*/
/*!
\fn bool QIntDictIterator::isEmpty() const
Returns TRUE if the dictionary is empty; otherwise eturns FALSE.
\sa count()
*/
/*!
\fn type *QIntDictIterator::toFirst()
Sets the current iterator item to point to the first item in the
dictionary and returns a pointer to the item. The first item
refers to the first item in the dictionary's arbitrary internal
ordering. If the dictionary is empty it sets the current item to
0 and returns 0.
*/
/*!
\fn QIntDictIterator::operator type *() const
Cast operator. Returns a pointer to the current iterator item.
Same as current().
*/
/*!
\fn type *QIntDictIterator::current() const
Returns a pointer to the current iterator item.
*/
/*!
\fn long QIntDictIterator::currentKey() const
Returns the key for the current iterator item.
*/
/*!
\fn type *QIntDictIterator::operator()()
Makes the succeeding item current and returns the original current
item.
If the current iterator item was the last item in the dictionary
or if it was 0, 0 is returned.
*/
/*!
\fn type *QIntDictIterator::operator++()
Prefix ++ makes the succeeding item current and returns the new
current item.
If the current iterator item was the last item in the dictionary
or if it was 0, 0 is returned.
*/
/*!
\fn type *QIntDictIterator::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 dictionary is
empty, it sets the current item to 0 and returns 0.
*/