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Diffstat (limited to 'src/corelib/kernel/qsequentialiterable.cpp')
| -rw-r--r-- | src/corelib/kernel/qsequentialiterable.cpp | 215 |
1 files changed, 215 insertions, 0 deletions
diff --git a/src/corelib/kernel/qsequentialiterable.cpp b/src/corelib/kernel/qsequentialiterable.cpp new file mode 100644 index 0000000000..c331f1de63 --- /dev/null +++ b/src/corelib/kernel/qsequentialiterable.cpp @@ -0,0 +1,215 @@ +// 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/qsequentialiterable.h> +#include <QtCore/qvariant.h> + +#include <QtCore/private/qiterable_p.h> + +QT_BEGIN_NAMESPACE + +/*! + \class QSequentialIterable + \since 5.2 + \inmodule QtCore + \brief The QSequentialIterable class is an iterable interface for a container in a QVariant. + + This class allows several methods of accessing the values of a container held within + a QVariant. An instance of QSequentialIterable can be extracted from a QVariant if it can + be converted to a QVariantList. + + \snippet code/src_corelib_kernel_qvariant.cpp 9 + + The container itself is not copied before iterating over it. + + \sa QVariant +*/ + +/*! + \typedef QSequentialIterable::RandomAccessIterator + Exposes an iterator using std::random_access_iterator_tag. +*/ + +/*! + \typedef QSequentialIterable::BidirectionalIterator + Exposes an iterator using std::bidirectional_iterator_tag. +*/ + +/*! + \typedef QSequentialIterable::ForwardIterator + Exposes an iterator using std::forward_iterator_tag. +*/ + +/*! + \typedef QSequentialIterable::InputIterator + Exposes an iterator using std::input_iterator_tag. +*/ + +/*! + \typedef QSequentialIterable::RandomAccessConstIterator + Exposes a const_iterator using std::random_access_iterator_tag. +*/ + +/*! + \typedef QSequentialIterable::BidirectionalConstIterator + Exposes a const_iterator using std::bidirectional_iterator_tag. +*/ + +/*! + \typedef QSequentialIterable::ForwardConstIterator + Exposes a const_iterator using std::forward_iterator_tag. +*/ + +/*! + \typedef QSequentialIterable::InputConstIterator + Exposes a const_iterator using std::input_iterator_tag. +*/ + +/*! + Adds \a value to the container, at \a position, if possible. + */ +void QSequentialIterable::addValue(const QVariant &value, Position position) +{ + QtPrivate::QVariantTypeCoercer coercer; + const void *valuePtr = coercer.coerce(value, metaContainer().valueMetaType()); + + switch (position) { + case AtBegin: + if (metaContainer().canAddValueAtBegin()) + metaContainer().addValueAtBegin(mutableIterable(), valuePtr); + break; + case AtEnd: + if (metaContainer().canAddValueAtEnd()) + metaContainer().addValueAtEnd(mutableIterable(), valuePtr); + break; + case Unspecified: + if (metaContainer().canAddValue()) + metaContainer().addValue(mutableIterable(), valuePtr); + break; + } +} + +/*! + Removes a value from the container, at \a position, if possible. + */ +void QSequentialIterable::removeValue(Position position) +{ + switch (position) { + case AtBegin: + if (metaContainer().canRemoveValueAtBegin()) + metaContainer().removeValueAtBegin(mutableIterable()); + break; + case AtEnd: + if (metaContainer().canRemoveValueAtEnd()) + metaContainer().removeValueAtEnd(mutableIterable()); + break; + case Unspecified: + if (metaContainer().canRemoveValue()) + metaContainer().removeValue(mutableIterable()); + break; + } +} + +QMetaType QSequentialIterable::valueMetaType() const +{ + return QMetaType(metaContainer().valueMetaType()); +} + +/*! + Returns the value at position \a idx in the container. +*/ +QVariant QSequentialIterable::at(qsizetype idx) const +{ + QVariant v(valueMetaType()); + void *dataPtr; + if (valueMetaType() == QMetaType::fromType<QVariant>()) + dataPtr = &v; + else + dataPtr = v.data(); + + const QMetaSequence meta = metaContainer(); + if (meta.canGetValueAtIndex()) { + meta.valueAtIndex(m_iterable.constPointer(), idx, dataPtr); + } else if (meta.canGetValueAtConstIterator()) { + void *iterator = meta.constBegin(m_iterable.constPointer()); + meta.advanceConstIterator(iterator, idx); + meta.valueAtConstIterator(iterator, dataPtr); + meta.destroyConstIterator(iterator); + } + + return v; +} + +/*! + Sets the element at position \a idx in the container to \a value. +*/ +void QSequentialIterable::set(qsizetype idx, const QVariant &value) +{ + QtPrivate::QVariantTypeCoercer coercer; + const void *dataPtr = coercer.coerce(value, metaContainer().valueMetaType()); + + const QMetaSequence meta = metaContainer(); + if (meta.canSetValueAtIndex()) { + meta.setValueAtIndex(m_iterable.mutablePointer(), idx, dataPtr); + } else if (meta.canSetValueAtIterator()) { + void *iterator = meta.begin(m_iterable.mutablePointer()); + meta.advanceIterator(iterator, idx); + meta.setValueAtIterator(iterator, dataPtr); + meta.destroyIterator(iterator); + } +} + +/*! + \typealias QSequentialIterable::const_iterator + \brief The QSequentialIterable::const_iterator allows iteration over a container in a QVariant. + + A QSequentialIterable::const_iterator can only be created by a QSequentialIterable instance, + and can be used in a way similar to other stl-style iterators. + + \snippet code/src_corelib_kernel_qvariant.cpp 9 +*/ + +/*! + \typealias QSequentialIterable::iterator + \since 6.0 + \brief The QSequentialIterable::iterator allows iteration over a container in a QVariant. + + A QSequentialIterable::iterator can only be created by a QSequentialIterable instance, + and can be used in a way similar to other stl-style iterators. +*/ + +/*! + Returns the current item, converted to a QVariantRef. +*/ +QVariantRef<QSequentialIterator> QSequentialIterator::operator*() const +{ + return QVariantRef<QSequentialIterator>(this); +} + +/*! + Returns the current item, converted to a QVariantPointer. +*/ +QVariantPointer<QSequentialIterator> QSequentialIterator::operator->() const +{ + return QVariantPointer<QSequentialIterator>(this); +} + +/*! + Returns the current item, converted to a QVariant. +*/ +QVariant QSequentialConstIterator::operator*() const +{ + return QIterablePrivate::retrieveElement(metaContainer().valueMetaType(), [this](void *dataPtr) { + metaContainer().valueAtConstIterator(constIterator(), dataPtr); + }); +} + +/*! + Returns the current item, converted to a QVariantConstPointer. +*/ +QVariantConstPointer QSequentialConstIterator::operator->() const +{ + return QVariantConstPointer(operator*()); +} + +QT_END_NAMESPACE |