QIntDict(3qt)QIntDict(3qt)NAME
QIntDict - Template class that provides a dictionary based on long keys
SYNOPSIS
#include <qintdict.h>
Inherits QPtrCollection.
Public Members
QIntDict ( int size = 17 )
QIntDict ( const QIntDict<type> & dict )
~QIntDict ()
QIntDict<type> & operator= ( const QIntDict<type> & dict )
virtual uint count () const
uint size () const
bool isEmpty () const
void insert ( long key, const type * item )
void replace ( long key, const type * item )
bool remove ( long key )
type * take ( long key )
type * find ( long key ) const
type * operator[] ( long key ) const
virtual void clear ()
void resize ( uint newsize )
void statistics () const
Important Inherited Members
bool autoDelete () const
void setAutoDelete ( bool enable )
Protected Members
virtual QDataStream & read ( QDataStream & s, QPtrCollection::Item &
item )
virtual QDataStream & write ( QDataStream & s, QPtrCollection::Item )
const
DESCRIPTION
The QIntDict class is a template class that provides a dictionary based
on long keys.
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 long
used for insertion, removal and lookup. The value is a pointer.
Dictionaries provide very fast insertion and lookup.
Example:
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"
See QDict for full details, including the choice of dictionary size,
and how deletions are handled.
See also QIntDictIterator, QDict, QAsciiDict, QPtrDict, Collection
Classes, Collection Classes, and Non-GUI Classes.
MEMBER FUNCTION DOCUMENTATIONQIntDict::QIntDict ( int size = 17 )
Constructs a dictionary using an internal hash array of size size.
Setting 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.
QIntDict::QIntDict ( const QIntDict<;type> & dict )
Constructs a copy of dict.
Each item in dict is inserted into this dictionary. Only the pointers
are copied (shallow copy).
QIntDict::~QIntDict ()
Removes all items from the dictionary and destroys it.
All iterators that access this dictionary will be reset.
See also setAutoDelete().
bool QPtrCollection::autoDelete () const
Returns the setting of the auto-delete option. The default is FALSE.
See also setAutoDelete().
void QIntDict::clear () [virtual]
Removes all items from the dictionary.
The removed items are deleted if auto-deletion is enabled.
All dictionary iterators that access this dictionary will be reset.
See also remove(), take(), and setAutoDelete().
Reimplemented from QPtrCollection.
uint QIntDict::count () const [virtual]
Returns the number of items in the dictionary.
See also isEmpty().
Reimplemented from QPtrCollection.
type * QIntDict::find ( long key ) const
Returns the item associated with 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[].
See also operator[]().
Example: table/bigtable/main.cpp.
void QIntDict::insert ( long key, const type * item )
Insert item item into the dictionary using key key.
Multiple items can have the same key, in which case only the last item
will be accessible using operator[]().
item may not be 0.
See also replace().
Example: scribble/scribble.cpp.
bool QIntDict::isEmpty () const
Returns TRUE if the dictionary is empty; otherwise returns FALSE.
See also count().
QIntDict<;type> & QIntDict::operator= ( const QIntDict<type> & dict )
Assigns dict to this dictionary and returns a reference to this
dictionary.
This dictionary is first cleared and then each item in dict is inserted
into this dictionary. Only the pointers are copied (shallow copy),
unless newItem() has been reimplemented.
type * QIntDict::operator[] ( long key ) const
Returns the item associated with 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.
See also find().
QDataStream & QIntDict::read ( QDataStream & s, QPtrCollection::Item & item )
[virtual protected]
Reads a dictionary item from the stream s and returns a reference to
the stream.
The default implementation sets item to 0.
See also write().
bool QIntDict::remove ( long key )
Removes the item associated with key from the dictionary. Returns TRUE
if successful, i.e. if the 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 auto-deletion 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.
See also take(), clear(), and setAutoDelete().
Example: table/bigtable/main.cpp.
void QIntDict::replace ( long key, const type * item )
If the dictionary has key key, this key's item is replaced with item.
If the dictionary doesn't contain key key, item is inserted into the
dictionary using key key.
item may not be 0.
Equivalent to:
QIntDict<char> dict;
// ...
if ( dict.find(key) )
dict.remove( key );
dict.insert( key, item );
If there are two or more items with equal keys, then the most recently
inserted item will be replaced.
See also insert().
Example: table/bigtable/main.cpp.
void QIntDict::resize ( uint newsize )
Changes the size of the hashtable to newsize. The contents of the
dictionary are preserved, but all iterators on the dictionary become
invalid.
void QPtrCollection::setAutoDelete ( bool enable )
Sets the collection to auto-delete its contents if enable is TRUE and
to never delete them if enable is FALSE.
If auto-deleting is turned on, all the items in a collection are
deleted when the collection itself is deleted. This is convenient if
the collection has the only pointer to the items.
The default setting is FALSE, for safety. If you turn it on, be careful
about copying the collection - you might find yourself with two
collections deleting the same items.
Note that the auto-delete setting may also affect other functions in
subclasses. For example, a subclass that has a remove() function will
remove the item from its data structure, and if auto-delete is enabled,
will also delete the item.
See also autoDelete().
Examples:
uint QIntDict::size () const
Returns the size of the internal hash array (as specified in the
constructor).
See also count().
void QIntDict::statistics () const
Debugging-only function that prints out the dictionary distribution
using qDebug().
type * QIntDict::take ( long key )
Takes the item associated with key out of the dictionary without
deleting it (even if auto-deletion 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.
See also remove(), clear(), and setAutoDelete().
Example: table/bigtable/main.cpp.
QDataStream & QIntDict::write ( QDataStream & s, QPtrCollection::Item ) const
[virtual protected]
Writes a dictionary item to the stream s and returns a reference to the
stream.
See also read().
SEE ALSO
http://doc.trolltech.com/qintdict.html
http://www.trolltech.com/faq/tech.html
COPYRIGHT
Copyright 1992-2007 Trolltech ASA, http://www.trolltech.com. See the
license file included in the distribution for a complete license
statement.
AUTHOR
Generated automatically from the source code.
BUGS
If you find a bug in Qt, please report it as described in
http://doc.trolltech.com/bughowto.html. Good bug reports help us to
help you. Thank you.
The definitive Qt documentation is provided in HTML format; it is
located at $QTDIR/doc/html and can be read using Qt Assistant or with a
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who prefer man pages, although this format is not officially supported
by Trolltech.
If you find errors in this manual page, please report them to qt-
bugs@trolltech.com. Please include the name of the manual page
(qintdict.3qt) and the Qt version (3.3.8).
Trolltech AS 2 February 2007 QIntDict(3qt)
