Detailed Description
The QCacheIterator class provides an iterator for QCache collections.
Note that the traversal order is arbitrary; you are not guaranteed
any particular order. If new objects are inserted into the cache
while the iterator is active, the iterator may or may not see
them.
Multiple iterators are completely independent, even when they
operate on the same QCache. QCache updates all iterators that
refer an item when that item is removed.
QCacheIterator provides an operator++(), and an operator+=() to
traverse the cache. The current() and currentKey() functions are
used to access the current cache item and its key. The atFirst()
and atLast() return TRUE if the iterator points to the first or
last item in the cache respectively. The isEmpty() function
returns TRUE if the cache is empty, and count() returns the number
of items in the cache.
Note that atFirst() and atLast() refer to the iterator's arbitrary
ordering, not to the cache's internal least recently used list.
See also QCache, Collection Classes and Non-GUI Classes.
Member Function Documentation
QCacheIterator::QCacheIterator ( const QCache<type> & cache )
Constructs an iterator for cache. The current iterator item is
set to point to the first item in the cache.
QCacheIterator::QCacheIterator ( const QCacheIterator<type> & ci )
Constructs an iterator for the same cache as ci. The new
iterator starts at the same item as ci.current(), but moves
independently from there on.
bool QCacheIterator::atFirst () const
Returns TRUE if the iterator points to the first item in the
cache; otherwise returns FALSE. Note that this refers to the
iterator's arbitrary ordering, not to the cache's internal least
recently used list.
See also toFirst() and atLast().
bool QCacheIterator::atLast () const
Returns TRUE if the iterator points to the last item in the cache;
otherwise returns FALSE. Note that this refers to the iterator's
arbitrary ordering, not to the cache's internal least recently
used list.
See also toLast() and atFirst().
uint QCacheIterator::count () const
Returns the number of items in the cache on which this iterator
operates.
See also isEmpty().
type * QCacheIterator::current () const
Returns a pointer to the current iterator item.
QString QCacheIterator::currentKey () const
Returns the key for the current iterator item.
bool QCacheIterator::isEmpty () const
Returns TRUE if the cache is empty, i.e. count() == 0; otherwise
it returns FALSE.
See also count().
QCacheIterator::operator type * () const
Cast operator. Returns a pointer to the current iterator item.
Same as current().
type * QCacheIterator::operator() ()
Makes the succeeding item current and returns the original current
item.
If the current iterator item was the last item in the cache or if
it was 0, 0 is returned.
type * QCacheIterator::operator++ ()
Prefix++ makes the iterator point to the item just after current()
and makes that the new current item for the iterator. If current()
was the last item, operator++() returns 0.
type * QCacheIterator::operator+= ( uint jump )
Returns the item jump positions after the current item, or 0 if
it is beyond the last item. Makes this the current item.
type * QCacheIterator::operator-- ()
Prefix-- makes the iterator point to the item just before
current() and makes that the new current item for the iterator. If
current() was the first item, operator--() returns 0.
type * QCacheIterator::operator-= ( uint jump )
Returns the item jump positions before the current item, or 0
if it is before the first item. Makes this the current item.
Makes this an iterator for the same cache as ci. The new
iterator starts at the same item as ci.current(), but moves
independently thereafter.
type * QCacheIterator::toFirst ()
Sets the iterator to point to the first item in the cache and
returns a pointer to the item.
Sets the iterator to 0 and returns 0 if the cache is empty.
See also toLast() and isEmpty().
type * QCacheIterator::toLast ()
Sets the iterator to point to the last item in the cache and
returns a pointer to the item.
Sets the iterator to 0 and returns 0 if the cache is empty.
See also toFirst() and isEmpty().
This file is part of the Qt toolkit.
Copyright © 1995-2002
Trolltech. All Rights Reserved.
