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QPtrDictIterator Class Reference
The QPtrDictIterator class provides an iterator for QPtrDict collections. More...
#include <qptrdict.h>
Public Members
- QPtrDictIterator ( const QPtrDict<type> & dict )
- uint count () const
- bool isEmpty () const
- type * toFirst ()
- operator type * () const
- type * current () const
- void * currentKey () const
- type * operator() ()
- type * operator++ ()
- type * operator+= ( uint jump )
Detailed Description
The QPtrDictIterator class provides an iterator for QPtrDict collections.
QPtrDictIterator is implemented as a template class. Define a template instance QPtrDictIterator<X> to create a dictionary iterator that operates on QPtrDict<X> (dictionary of X*).
Example:
QPtrDict<char> extra; QLineEdit *le1 = new QLineEdit( this ); le1->setText( "Simpson" ); QLineEdit *le2 = new QLineEdit( this ); le2->setText( "Homer" ); QLineEdit *le3 = new QLineEdit( this ); le3->setText( "45" ); extra.insert( le1, "Surname" ); extra.insert( le2, "Forename" ); extra.insert( le3, "Age" ); QPtrDictIterator<char> it( extra ); for( ; it.current(); ++it ) { QLineEdit *le = (QLineEdit)it.currentKey(); cout << it.current() << ": " << le->text() << endl; } cout << endl; // Output (random order): // Forename: Homer // Age: 45 // Surname: SimpsonIn the example we insert some line edits into a dictionary, then iterate over the dictionary printing the strings associated with those line edits.
Multiple iterators may independently traverse the same dictionary. A QPtrDict knows about all iterators that are operating on the dictionary. When an item is removed from the dictionary, QPtrDict updates all iterators that refer the removed item to point to the next item in the traversing order.
See also QPtrDict, Collection Classes and Non-GUI Classes.
Member Function Documentation
QPtrDictIterator::QPtrDictIterator ( const QPtrDict<type> & dict )
Constructs an iterator for dict. The current iterator item is set to point on the first item in the dict.QPtrDictIterator::~QPtrDictIterator ()
Destroys the iterator.uint QPtrDictIterator::count () const
Returns the number of items in the dictionary this iterator operates on.See also isEmpty().
type * QPtrDictIterator::current () const
Returns a pointer to the current iterator item.void * QPtrDictIterator::currentKey () const
Returns the key for the current iterator item.bool QPtrDictIterator::isEmpty () const
Returns TRUE if the dictionary is empty; otherwise returns FALSE.See also count().
QPtrDictIterator::operator type * () const
Cast operator. Returns a pointer to the current iterator item. Same as current().type * QPtrDictIterator::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 null, null is returned.
type * QPtrDictIterator::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 null, null is returned.
type * QPtrDictIterator::operator+= ( uint jump )
Sets the current item to the item 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.
type * QPtrDictIterator::toFirst ()
Sets the current iterator item to point to the first item in the dictionary and returns a pointer to the item. If the dictionary is empty, it sets the current item to null and returns null.This file is part of the Qt toolkit. Copyright © 1995-2002 Trolltech. All Rights Reserved.
Copyright © 2002 Trolltech | Trademarks | Qt version 3.0.5
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