path: root/src/corelib/kernel/qsequentialiterable.cpp

// 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. */voidQSequentialIterable::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. */voidQSequentialIterable::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{returnQMetaType(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.*/voidQSequentialIterable::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{returnQIterablePrivate::retrieveElement(metaContainer().valueMetaType(), [this](void*dataPtr) {metaContainer().valueAtConstIterator(constIterator(), dataPtr);});}/*! Returns the current item, converted to a QVariantConstPointer.*/ QVariantConstPointer QSequentialConstIterator::operator->()const{returnQVariantConstPointer(operator*());} QT_END_NAMESPACE