QAsciiDictIterator Class

Qt 3.0.5

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QAsciiDictIterator Class Reference

The QAsciiDictIterator class provides an iterator for QAsciiDict collections. More...

#include <qasciidict.h>

List of all member functions.

Public Members

QAsciiDictIterator ( const QAsciiDict<type> & dict )
~QAsciiDictIterator ()
uint count () const
bool isEmpty () const
type * toFirst ()
operator type * () const
type * current () const
const char * currentKey () const
type * operator() ()
type * operator++ ()
type * operator+= ( uint jump )

Detailed Description

The QAsciiDictIterator class provides an iterator for QAsciiDict collections.

QAsciiDictIterator is implemented as a template class. Define a template instance QAsciiDictIterator<X> to create a dictionary iterator that operates on QAsciiDict<X> (dictionary of X*).

Example:

    QAsciiDict<QLineEdit> fields;
    fields.insert( "forename", new QLineEdit( this ) );
    fields.insert( "surname", new QLineEdit( this ) );
    fields.insert( "age", new QLineEdit( this ) );

    fields["forename"]->setText( "Homer" );
    fields["surname"]->setText( "Simpson" );
    fields["age"]->setText( "45" );

    QAsciiDictIterator<QLineEdit> it( fields );
    for( ; it.current(); ++it )
        cout << it.currentKey() << ": " << it.current()->text() << endl;
    cout << endl;

    // Output (random order):
    //  age: 45
    //  surname: Simpson
    //  forename: Homer

In the example we insert some line edits into a dictionary, then iterate over the dictionary printing the strings associated with those line edits.

Note that the traversal order is arbitrary; you are not guaranteed any particular order.

Multiple iterators may independently traverse the same dictionary. A QAsciiDict knows about all the iterators that are operating on the dictionary. When an item is removed from the dictionary, QAsciiDict updates all the iterators that are referring the removed item to point to the next item in the (arbitrary) traversal order.

Member Function Documentation

QAsciiDictIterator::QAsciiDictIterator ( const QAsciiDict<type> & dict )

Constructs an iterator for dict. The current iterator item is set to point on the first item in the dict.

QAsciiDictIterator::~QAsciiDictIterator ()

Destroys the iterator.

uint QAsciiDictIterator::count () const

Returns the number of items in the dictionary this iterator operates over.

type * QAsciiDictIterator::current () const

Returns a pointer to the current iterator item.

const char * QAsciiDictIterator::currentKey () const

Returns a pointer to the key for the current iterator item.

bool QAsciiDictIterator::isEmpty () const

Returns TRUE if the dictionary is empty, i.e. count() == 0, otherwise returns FALSE.

QAsciiDictIterator::operator type * () const

Cast operator. Returns a pointer to the current iterator item. Same as current().

type * QAsciiDictIterator::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 * QAsciiDictIterator::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 * QAsciiDictIterator::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 * QAsciiDictIterator::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.

Trademarks

Qt version 3.0.5

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