QMapIterator Class

QMap<int, QWidget *> map;
...
QMapIterator<int, QWidget *> i(map);
while (i.hasNext()) {
    i.next();
    qDebug() << i.key() << ": " << i.value();
}

QMapIterator<int, QWidget *> i(map);
i.toBack();
while (i.hasPrevious()) {
    i.previous();
    qDebug() << i.key() << ": " << i.value();
}

QMapIterator<int, QWidget *> i(map);
while (i.findNext(widget)) {
    qDebug() << "Found widget " << widget << " under key "
             << i.key();
}

Member Function Documentation

QMapIterator::QMapIterator(const QMap<Key, T> &map)

Constructs an iterator for traversing map. The iterator is set to be at the front of the map (before the first item).

See also operator=().

QMapIterator<Key, T> &QMapIterator::operator=(const QMap<Key, T> &container)

Makes the iterator operate on map. The iterator is set to be at the front of the map (before the first item).

See also toFront() and toBack().

void QMapIterator::toFront()

Moves the iterator to the front of the container (before the first item).

See also toBack() and next().

void QMapIterator::toBack()

Moves the iterator to the back of the container (after the last item).

See also toFront() and previous().

bool QMapIterator::hasNext() const

Returns true if there is at least one item ahead of the iterator, i.e. the iterator is not at the back of the container; otherwise returns false.

See also hasPrevious() and next().

QMapIterator::Item QMapIterator::next()

Returns the next item and advances the iterator by one position.

Call key() on the return value to obtain the item's key, and value() to obtain the value.

Calling this function on an iterator located at the back of the container leads to undefined results.

See also hasNext(), peekNext(), and previous().

QMapIterator::Item QMapIterator::peekNext() const

Returns the next item without moving the iterator.

Call key() on the return value to obtain the item's key, and value() to obtain the value.

Calling this function on an iterator located at the back of the container leads to undefined results.

See also hasNext(), next(), and peekPrevious().

bool QMapIterator::hasPrevious() const

Returns true if there is at least one item behind the iterator, i.e. the iterator is not at the front of the container; otherwise returns false.

See also hasNext() and previous().

QMapIterator::Item QMapIterator::previous()

Returns the previous item and moves the iterator back by one position.

Call key() on the return value to obtain the item's key, and value() to obtain the value.

Calling this function on an iterator located at the front of the container leads to undefined results.

See also hasPrevious(), peekPrevious(), and next().

QMapIterator::Item QMapIterator::peekPrevious() const

Returns the previous item without moving the iterator.

Call key() on the return value to obtain the item's key, and value() to obtain the value.

Calling this function on an iterator located at the front of the container leads to undefined results.

See also hasPrevious(), previous(), and peekNext().

const T &QMapIterator::value() const

Returns the value of the last item that was jumped over using one of the traversal functions (next(), previous(), findNext(), findPrevious()).

After a call to next() or findNext(), value() is equivalent to peekPrevious().value(). After a call to previous() or findPrevious(), value() is equivalent to peekNext().value().

See also key().

const Key &QMapIterator::key() const

Returns the key of the last item that was jumped over using one of the traversal functions (next(), previous(), findNext(), findPrevious()).

After a call to next() or findNext(), key() is equivalent to peekPrevious().key(). After a call to previous() or findPrevious(), key() is equivalent to peekNext().key().

See also value().

bool QMapIterator::findNext(const T &value)

Searches for value starting from the current iterator position forward. Returns true if a (key, value) pair with value value is found; otherwise returns false.

After the call, if value was found, the iterator is positioned just after the matching item; otherwise, the iterator is positioned at the back of the container.

See also findPrevious().

bool QMapIterator::findPrevious(const T &value)

Searches for value starting from the current iterator position backward. Returns true if a (key, value) pair with value value is found; otherwise returns false.

After the call, if value was found, the iterator is positioned just before the matching item; otherwise, the iterator is positioned at the front of the container.

See also findNext().