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Diffstat (limited to 'src/corelib/kernel/qassociativeiterable.cpp')
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diff --git a/src/corelib/kernel/qassociativeiterable.cpp b/src/corelib/kernel/qassociativeiterable.cpp new file mode 100644 index 0000000000..780ae35a42 --- /dev/null +++ b/src/corelib/kernel/qassociativeiterable.cpp @@ -0,0 +1,253 @@ +/**************************************************************************** +** +** Copyright (C) 2020 The Qt Company Ltd. +** Contact: https://www.qt.io/licensing/ +** +** This file is part of the QtCore module of the Qt Toolkit. +** +** $QT_BEGIN_LICENSE:LGPL$ +** Commercial License Usage +** Licensees holding valid commercial Qt licenses may use this file in +** accordance with the commercial license agreement provided with the +** Software or, alternatively, in accordance with the terms contained in +** a written agreement between you and The Qt Company. For licensing terms +** and conditions see https://www.qt.io/terms-conditions. For further +** information use the contact form at https://www.qt.io/contact-us. +** +** GNU Lesser General Public License Usage +** Alternatively, this file may be used under the terms of the GNU Lesser +** General Public License version 3 as published by the Free Software +** Foundation and appearing in the file LICENSE.LGPL3 included in the +** packaging of this file. Please review the following information to +** ensure the GNU Lesser General Public License version 3 requirements +** will be met: https://www.gnu.org/licenses/lgpl-3.0.html. +** +** GNU General Public License Usage +** Alternatively, this file may be used under the terms of the GNU +** General Public License version 2.0 or (at your option) the GNU General +** Public license version 3 or any later version approved by the KDE Free +** Qt Foundation. The licenses are as published by the Free Software +** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3 +** included in the packaging of this file. Please review the following +** information to ensure the GNU General Public License requirements will +** be met: https://www.gnu.org/licenses/gpl-2.0.html and +** https://www.gnu.org/licenses/gpl-3.0.html. +** +** $QT_END_LICENSE$ +** +****************************************************************************/ + +#include <QtCore/qassociativeiterable.h> +#include <QtCore/qvariant.h> + +#include <QtCore/private/qiterable_p.h> + +QT_BEGIN_NAMESPACE + +/*! + Returns the key this iterator points to. +*/ +QVariant QAssociativeIterator::key() const +{ + return QIterablePrivate::retrieveElement( + metaContainer().keyMetaType(), [this](void *dataPtr) { + metaContainer().keyAtIterator(constIterator(), dataPtr); + }); +} + +/*! + Returns the mapped value this iterator points to. If the container does not + provide a mapped value (for example a set), returns an invalid QVariantRef. +*/ +QVariantRef<QAssociativeIterator> QAssociativeIterator::value() const +{ + const QMetaType mappedMetaType(metaContainer().mappedMetaType()); + return QVariantRef<QAssociativeIterator>(mappedMetaType.isValid() ? this : nullptr); +} + +/*! + Returns the current item, converted to a QVariantRef. The resulting + QVariantRef resolves to the mapped value if there is one, or to the key + value if not. +*/ +QVariantRef<QAssociativeIterator> QAssociativeIterator::operator*() const +{ + return QVariantRef<QAssociativeIterator>(this); +} + +/*! + Returns the current item, converted to a QVariantPointer. The resulting + QVariantPointer resolves to the mapped value if there is one, or to the key + value if not. +*/ +QVariantPointer<QAssociativeIterator> QAssociativeIterator::operator->() const +{ + return QVariantPointer<QAssociativeIterator>(this); +} + +/*! + Returns the key this iterator points to. +*/ +QVariant QAssociativeConstIterator::key() const +{ + return QIterablePrivate::retrieveElement( + metaContainer().keyMetaType(), [this](void *dataPtr) { + metaContainer().keyAtConstIterator(constIterator(), dataPtr); + }); +} + +/*! + Returns the mapped value this iterator points to, or an invalid QVariant if + there is no mapped value. +*/ +QVariant QAssociativeConstIterator::value() const +{ + return QIterablePrivate::retrieveElement( + metaContainer().mappedMetaType(), [this](void *dataPtr) { + metaContainer().mappedAtConstIterator(constIterator(), dataPtr); + }); +} + +/*! + Returns the current item, converted to a QVariant. The returned value is the + mapped value at the current iterator if there is one, or otherwise the key. +*/ +QVariant QAssociativeConstIterator::operator*() const +{ + const QMetaType mappedMetaType(metaContainer().mappedMetaType()); + return mappedMetaType.isValid() ? value() : key(); +} + +/*! + Returns the current item, converted to a QVariantConstPointer. The + QVariantConstPointer will resolve to the mapped value at the current + iterator if there is one, or otherwise the key. +*/ +QVariantConstPointer QAssociativeConstIterator::operator->() const +{ + return QVariantConstPointer(operator*()); +} + +/*! + \class QAssociativeIterable + \since 5.2 + \inmodule QtCore + \brief The QAssociativeIterable class is an iterable interface for an associative container in a QVariant. + + This class allows several methods of accessing the elements of an associative container held within + a QVariant. An instance of QAssociativeIterable can be extracted from a QVariant if it can + be converted to a QVariantHash or QVariantMap or if a custom mutable view has been registered. + + \snippet code/src_corelib_kernel_qvariant.cpp 10 + + The container itself is not copied before iterating over it. + + \sa QVariant +*/ + +/*! + \typedef QAssociativeIterable::RandomAccessIterator + Exposes an iterator using std::random_access_iterator_tag. +*/ + +/*! + \typedef QAssociativeIterable::BidirectionalIterator + Exposes an iterator using std::bidirectional_iterator_tag. +*/ + +/*! + \typedef QAssociativeIterable::ForwardIterator + Exposes an iterator using std::forward_iterator_tag. +*/ + +/*! + \typedef QAssociativeIterable::InputIterator + Exposes an iterator using std::input_iterator_tag. +*/ + +/*! + \typedef QAssociativeIterable::RandomAccessConstIterator + Exposes a const_iterator using std::random_access_iterator_tag. +*/ + +/*! + \typedef QAssociativeIterable::BidirectionalConstIterator + Exposes a const_iterator using std::bidirectional_iterator_tag. +*/ + +/*! + \typedef QAssociativeIterable::ForwardConstIterator + Exposes a const_iterator using std::forward_iterator_tag. +*/ + +/*! + \typedef QAssociativeIterable::InputConstIterator + Exposes a const_iterator using std::input_iterator_tag. +*/ + +/*! + Retrieves a const_iterator pointing to the element at the given \a key, or + the end of the container if that key does not exist. + */ +QAssociativeIterable::const_iterator QAssociativeIterable::find(const QVariant &key) const +{ + const QMetaAssociation meta = metaContainer(); + QVariant converted = key; + const void *keyData = QIterablePrivate::coerceType(converted, meta.keyMetaType()); + return const_iterator(QConstIterator( + this, meta.createConstIteratorAtKey(constIterable(), keyData))); +} + +/*! + Retrieves an iterator pointing to the element at the given \a key, or + the end of the container if that key does not exist. + */ +QAssociativeIterable::iterator QAssociativeIterable::mutableFind(const QVariant &key) +{ + const QMetaAssociation meta = metaContainer(); + QVariant converted = key; + const void *keyData = QIterablePrivate::coerceType(converted, meta.keyMetaType()); + return iterator(QIterator(this, meta.createIteratorAtKey(mutableIterable(), keyData))); +} + +/*! + Retrieves the mapped value at the given \a key, or an invalid QVariant + if the key does not exist. + */ +QVariant QAssociativeIterable::value(const QVariant &key) const +{ + const QMetaAssociation meta = metaContainer(); + QVariant converted = key; + const void *keyData = QIterablePrivate::coerceType(converted, meta.keyMetaType()); + QVariant result(QMetaType(meta.mappedMetaType())); + meta.mappedAtKey(constIterable(), keyData, result.data()); + return result; +} + +/*! + \class QAssociativeIterable::const_iterator + \since 5.2 + \inmodule QtCore + \brief The QAssociativeIterable::const_iterator allows iteration over a container in a QVariant. + + A QAssociativeIterable::const_iterator can only be created by a QAssociativeIterable instance, + and can be used in a way similar to other stl-style iterators. + + \snippet code/src_corelib_kernel_qvariant.cpp 10 + + \sa QAssociativeIterable +*/ + +/*! + \class QAssociativeIterable::iterator + \since 6.0 + \inmodule QtCore + \brief The QAssociativeIterable::iterator allows iteration over a container in a QVariant. + + A QAssociativeIterable::iterator can only be created by a QAssociativeIterable instance, + and can be used in a way similar to other stl-style iterators. + + \sa QAssociativeIterable +*/ + +QT_END_NAMESPACE |