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Diffstat (limited to 'src/corelib/kernel/qassociativeiterable.cpp')
| -rw-r--r-- | src/corelib/kernel/qassociativeiterable.cpp | 287 |
1 files changed, 287 insertions, 0 deletions
diff --git a/src/corelib/kernel/qassociativeiterable.cpp b/src/corelib/kernel/qassociativeiterable.cpp new file mode 100644 index 0000000000..db17c392a2 --- /dev/null +++ b/src/corelib/kernel/qassociativeiterable.cpp @@ -0,0 +1,287 @@ +// Copyright (C) 2020 The Qt Company Ltd. +// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only + +#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. If the \a key isn't + convertible to the expected type, the end of the container is returned. + */ +QAssociativeIterable::const_iterator QAssociativeIterable::find(const QVariant &key) const +{ + const QMetaAssociation meta = metaContainer(); + QtPrivate::QVariantTypeCoercer coercer; + if (const void *keyData = coercer.convert(key, meta.keyMetaType())) { + return const_iterator(QConstIterator(this, meta.createConstIteratorAtKey( + constIterable(), keyData))); + } + return constEnd(); +} + +/*! + Retrieves an iterator pointing to the element at the given \a key, or + the end of the container if that key does not exist. If the \a key isn't + convertible to the expected type, the end of the container is returned. + */ +QAssociativeIterable::iterator QAssociativeIterable::mutableFind(const QVariant &key) +{ + const QMetaAssociation meta = metaContainer(); + QtPrivate::QVariantTypeCoercer coercer; + if (const void *keyData = coercer.convert(key, meta.keyMetaType())) + return iterator(QIterator(this, meta.createIteratorAtKey(mutableIterable(), keyData))); + return mutableEnd(); +} + +/*! + Returns \c true if the container has an entry with the given \a key, or + \c false otherwise. If the \a key isn't convertible to the expected type, + \c false is returned. + */ +bool QAssociativeIterable::containsKey(const QVariant &key) +{ + QtPrivate::QVariantTypeCoercer keyCoercer; + QMetaAssociation meta = metaContainer(); + if (const void *keyData = keyCoercer.convert(key, meta.keyMetaType())) + return meta.containsKey(constIterable(), keyData); + return false; +} + +/*! + Inserts a new entry with the given \a key, or resets the mapped value of + any existing entry with the given \a key to the default constructed + mapped value. The \a key is coerced to the expected type: If it isn't + convertible, a default value is inserted. + */ +void QAssociativeIterable::insertKey(const QVariant &key) +{ + QMetaAssociation meta = metaContainer(); + QtPrivate::QVariantTypeCoercer keyCoercer; + meta.insertKey(mutableIterable(), keyCoercer.coerce(key, meta.keyMetaType())); +} + +/*! + Removes the entry with the given \a key from the container. The \a key is + coerced to the expected type: If it isn't convertible, the default value + is removed. + */ +void QAssociativeIterable::removeKey(const QVariant &key) +{ + QMetaAssociation meta = metaContainer(); + QtPrivate::QVariantTypeCoercer keyCoercer; + meta.removeKey(mutableIterable(), keyCoercer.coerce(key, meta.keyMetaType())); +} + + +/*! + Retrieves the mapped value at the given \a key, or a default-constructed + QVariant of the mapped type, if the key does not exist. If the \a key is not + convertible to the key type, the mapped value associated with the + default-constructed key is returned. + */ +QVariant QAssociativeIterable::value(const QVariant &key) const +{ + const QMetaAssociation meta = metaContainer(); + const QMetaType mappedMetaType = meta.mappedMetaType(); + + QtPrivate::QVariantTypeCoercer coercer; + const void *keyData = coercer.coerce(key, meta.keyMetaType()); + + if (mappedMetaType == QMetaType::fromType<QVariant>()) { + QVariant result; + meta.mappedAtKey(constIterable(), keyData, &result); + return result; + } + + QVariant result(mappedMetaType); + meta.mappedAtKey(constIterable(), keyData, result.data()); + return result; +} + +/*! + Sets the mapped value associated with \a key to \a mapped, if possible. + Inserts a new entry if none exists yet, for the given \a key. If the \a key + is not convertible to the key type, the value for the default-constructed + key type is overwritten. + */ +void QAssociativeIterable::setValue(const QVariant &key, const QVariant &mapped) +{ + QtPrivate::QVariantTypeCoercer keyCoercer; + QtPrivate::QVariantTypeCoercer mappedCoercer; + QMetaAssociation meta = metaContainer(); + meta.setMappedAtKey(mutableIterable(), keyCoercer.coerce(key, meta.keyMetaType()), + mappedCoercer.coerce(mapped, meta.mappedMetaType())); +} + +/*! + \typealias QAssociativeIterable::const_iterator + \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 +*/ + +/*! + \typealias 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 |