qsortfilterproxymodel.cpp

Go to the documentation of this file.

// Copyright (C) 2016 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 "qsortfilterproxymodel.h"
#include "qitemselectionmodel.h"
#include <qsize.h>
#include <qdebug.h>
#include <qdatetime.h>
#include <qstringlist.h>
#include <private/qabstractitemmodel_p.h>
#include <private/qabstractproxymodel_p.h>
#include <private/qproperty_p.h>
 
#include <algorithm>
 
QT_BEGIN_NAMESPACE
 
using QModelIndexPairList = QList<std::pair<QModelIndex, QPersistentModelIndex>>;
 
struct QSortFilterProxyModelDataChanged
{
    QSortFilterProxyModelDataChanged(const QModelIndex &tl, const QModelIndex &br)
        : topLeft(tl), bottomRight(br) { }
 
    QModelIndex topLeft;
    QModelIndex bottomRight;
};
 
static inline QSet<int> qListToSet(const QList<int> &vector)
{
    return {vector.begin(), vector.end()};
}
 
class QSortFilterProxyModelLessThan
{
public:
    inline QSortFilterProxyModelLessThan(int column, const QModelIndex &parent,
                                       const QAbstractItemModel *source,
                                       const QSortFilterProxyModel *proxy)
        : sort_column(column), source_parent(parent), source_model(source), proxy_model(proxy) {}
 
    inline bool operator()(int r1, int r2) const
    {
        QModelIndex i1 = source_model->index(r1, sort_column, source_parent);
        QModelIndex i2 = source_model->index(r2, sort_column, source_parent);
        return proxy_model->lessThan(i1, i2);
    }
 
private:
    int sort_column;
    QModelIndex source_parent;
    const QAbstractItemModel *source_model;
    const QSortFilterProxyModel *proxy_model;
};
 
class QSortFilterProxyModelGreaterThan
{
public:
    inline QSortFilterProxyModelGreaterThan(int column, const QModelIndex &parent,
                                          const QAbstractItemModel *source,
                                          const QSortFilterProxyModel *proxy)
        : sort_column(column), source_parent(parent),
          source_model(source), proxy_model(proxy) {}
 
    inline bool operator()(int r1, int r2) const
    {
        QModelIndex i1 = source_model->index(r1, sort_column, source_parent);
        QModelIndex i2 = source_model->index(r2, sort_column, source_parent);
        return proxy_model->lessThan(i2, i1);
    }
 
private:
    int sort_column;
    QModelIndex source_parent;
    const QAbstractItemModel *source_model;
    const QSortFilterProxyModel *proxy_model;
};
 
 
//this struct is used to store what are the rows that are removed
//between a call to rowsAboutToBeRemoved and rowsRemoved
//it avoids readding rows to the mapping that are currently being removed
struct QRowsRemoval
{
    QRowsRemoval(const QModelIndex &parent_source, int start, int end) : parent_source(parent_source), start(start), end(end)
    {
    }
 
    QRowsRemoval() : start(-1), end(-1)
    {
    }
 
    bool contains(QModelIndex parent, int row) const
    {
        do {
            if (parent == parent_source)
                return row >= start && row <= end;
            row = parent.row();
            parent = parent.parent();
        } while (row >= 0);
        return false;
    }
private:
    QModelIndex parent_source;
    int start;
    int end;
};
 
class QSortFilterProxyModelPrivate : public QAbstractProxyModelPrivate
{
public:
    Q_DECLARE_PUBLIC(QSortFilterProxyModel)
 
    enum class Direction {
        Rows = 1,
        Columns = 2,
        All = Rows | Columns
    };
 
    struct Mapping {
        QList<int> source_rows;
        QList<int> source_columns;
        QList<int> proxy_rows;
        QList<int> proxy_columns;
        QList<QModelIndex> mapped_children;
        QModelIndex source_parent;
    };
 
    mutable QHash<QModelIndex, Mapping*> source_index_mapping;
 
    void setSortCaseSensitivityForwarder(Qt::CaseSensitivity cs)
    {
        q_func()->setSortCaseSensitivity(cs);
    }
    void sortCaseSensitivityChangedForwarder(Qt::CaseSensitivity cs)
    {
        emit q_func()->sortCaseSensitivityChanged(cs);
    }
 
    void setSortRoleForwarder(int role) { q_func()->setSortRole(role); }
    void sortRoleChangedForwarder(int role) { emit q_func()->sortRoleChanged(role); }
 
    void setSortLocaleAwareForwarder(bool on) { q_func()->setSortLocaleAware(on); }
    void sortLocaleAwareChangedForwarder(bool on) { emit q_func()->sortLocaleAwareChanged(on); }
 
    void setFilterKeyColumnForwarder(int column) { q_func()->setFilterKeyColumn(column); }
 
    void setFilterRoleForwarder(int role) { q_func()->setFilterRole(role); }
    void filterRoleChangedForwarder(int role) { emit q_func()->filterRoleChanged(role); }
 
    void setRecursiveFilteringEnabledForwarder(bool recursive)
    {
        q_func()->setRecursiveFilteringEnabled(recursive);
    }
    void recursiveFilteringEnabledChangedForwarder(bool recursive)
    {
        emit q_func()->recursiveFilteringEnabledChanged(recursive);
    }
 
    void setAutoAcceptChildRowsForwarder(bool accept) { q_func()->setAutoAcceptChildRows(accept); }
    void autoAcceptChildRowsChangedForwarder(bool accept)
    {
        emit q_func()->autoAcceptChildRowsChanged(accept);
    }
 
    void setDynamicSortFilterForwarder(bool enable) { q_func()->setDynamicSortFilter(enable); }
 
    void setFilterCaseSensitivityForwarder(Qt::CaseSensitivity cs)
    {
        q_func()->setFilterCaseSensitivity(cs);
    }
    void filterCaseSensitivityChangedForwarder(Qt::CaseSensitivity cs)
    {
        emit q_func()->filterCaseSensitivityChanged(cs);
    }
 
    void setFilterRegularExpressionForwarder(const QRegularExpression &re)
    {
        q_func()->setFilterRegularExpression(re);
    }
 
    int source_sort_column = -1;
    int proxy_sort_column = -1;
    Qt::SortOrder sort_order = Qt::AscendingOrder;
    bool complete_insert = false;
 
    Q_OBJECT_COMPAT_PROPERTY_WITH_ARGS(
            QSortFilterProxyModelPrivate, Qt::CaseSensitivity, sort_casesensitivity,
            &QSortFilterProxyModelPrivate::setSortCaseSensitivityForwarder,
            &QSortFilterProxyModelPrivate::sortCaseSensitivityChangedForwarder, Qt::CaseSensitive)
 
    Q_OBJECT_COMPAT_PROPERTY_WITH_ARGS(QSortFilterProxyModelPrivate, int, sort_role,
                                       &QSortFilterProxyModelPrivate::setSortRoleForwarder,
                                       &QSortFilterProxyModelPrivate::sortRoleChangedForwarder,
                                       Qt::DisplayRole)
 
    Q_OBJECT_COMPAT_PROPERTY_WITH_ARGS(QSortFilterProxyModelPrivate, int, filter_column,
                                       &QSortFilterProxyModelPrivate::setFilterKeyColumnForwarder,
                                       0)
 
    Q_OBJECT_COMPAT_PROPERTY_WITH_ARGS(QSortFilterProxyModelPrivate, int, filter_role,
                                       &QSortFilterProxyModelPrivate::setFilterRoleForwarder,
                                       &QSortFilterProxyModelPrivate::filterRoleChangedForwarder,
                                       Qt::DisplayRole)
 
    Q_OBJECT_COMPAT_PROPERTY_WITH_ARGS(
            QSortFilterProxyModelPrivate, bool, sort_localeaware,
            &QSortFilterProxyModelPrivate::setSortLocaleAwareForwarder,
            &QSortFilterProxyModelPrivate::sortLocaleAwareChangedForwarder, false)
 
    Q_OBJECT_COMPAT_PROPERTY_WITH_ARGS(
            QSortFilterProxyModelPrivate, bool, filter_recursive,
            &QSortFilterProxyModelPrivate::setRecursiveFilteringEnabledForwarder,
            &QSortFilterProxyModelPrivate::recursiveFilteringEnabledChangedForwarder, false)
 
    Q_OBJECT_COMPAT_PROPERTY_WITH_ARGS(
            QSortFilterProxyModelPrivate, bool, accept_children,
            &QSortFilterProxyModelPrivate::setAutoAcceptChildRowsForwarder,
            &QSortFilterProxyModelPrivate::autoAcceptChildRowsChangedForwarder, false)
 
    Q_OBJECT_COMPAT_PROPERTY_WITH_ARGS(QSortFilterProxyModelPrivate, bool, dynamic_sortfilter,
                                       &QSortFilterProxyModelPrivate::setDynamicSortFilterForwarder,
                                       true)
 
    Q_OBJECT_COMPAT_PROPERTY_WITH_ARGS(
            QSortFilterProxyModelPrivate, Qt::CaseSensitivity, filter_casesensitive,
            &QSortFilterProxyModelPrivate::setFilterCaseSensitivityForwarder,
            &QSortFilterProxyModelPrivate::filterCaseSensitivityChangedForwarder, Qt::CaseSensitive)
 
    Q_OBJECT_COMPAT_PROPERTY(QSortFilterProxyModelPrivate, QRegularExpression,
                             filter_regularexpression,
                             &QSortFilterProxyModelPrivate::setFilterRegularExpressionForwarder)
 
    QModelIndex last_top_source;
    QRowsRemoval itemsBeingRemoved;
 
    QModelIndexPairList saved_persistent_indexes;
    QList<QPersistentModelIndex> saved_layoutChange_parents;
 
    std::array<QMetaObject::Connection, 18> sourceConnections;
 
    QHash<QModelIndex, Mapping *>::const_iterator create_mapping(
        const QModelIndex &source_parent) const;
    QHash<QModelIndex, Mapping *>::const_iterator create_mapping_recursive(
            const QModelIndex &source_parent) const;
    QModelIndex proxy_to_source(const QModelIndex &proxyIndex) const;
    QModelIndex source_to_proxy(const QModelIndex &sourceIndex) const;
    bool can_create_mapping(const QModelIndex &source_parent) const;
 
    void remove_from_mapping(const QModelIndex &source_parent);
 
    /*
     * Legacy: changing the pattern through a string does not change the
     * case sensitivity.
     */
    void set_filter_pattern(const QString &pattern)
    {
        QRegularExpression re = filter_regularexpression.valueBypassingBindings();
        const auto cs = re.patternOptions() & QRegularExpression::CaseInsensitiveOption;
        re.setPattern(pattern);
        re.setPatternOptions(cs);
        // This is a helper function, which is supposed to be called from a
        // more complicated context. Because of that, the caller is responsible
        // for calling notify() and removeBindingUnlessInWrapper(), if needed.
        filter_regularexpression.setValueBypassingBindings(re);
    }
 
    inline QHash<QModelIndex, Mapping *>::const_iterator index_to_iterator(
        const QModelIndex &proxy_index) const
    {
        Q_ASSERT(proxy_index.isValid());
        Q_ASSERT(proxy_index.model() == q_func());
        const void *p = proxy_index.internalPointer();
        Q_ASSERT(p);
        QHash<QModelIndex, Mapping *>::const_iterator it =
                source_index_mapping.constFind(static_cast<const Mapping*>(p)->source_parent);
        Q_ASSERT(it != source_index_mapping.constEnd());
        Q_ASSERT(it.value());
        return it;
    }
 
    inline QModelIndex create_index(int row, int column,
                                    QHash<QModelIndex, Mapping*>::const_iterator it) const
    {
        return q_func()->createIndex(row, column, *it);
    }
 
    void _q_sourceDataChanged(const QModelIndex &source_top_left,
                              const QModelIndex &source_bottom_right,
                              const QList<int> &roles);
    void _q_sourceHeaderDataChanged(Qt::Orientation orientation, int start, int end);
 
    void _q_sourceAboutToBeReset();
    void _q_sourceReset();
 
    void _q_sourceLayoutAboutToBeChanged(const QList<QPersistentModelIndex> &sourceParents, QAbstractItemModel::LayoutChangeHint hint);
    void _q_sourceLayoutChanged(const QList<QPersistentModelIndex> &sourceParents, QAbstractItemModel::LayoutChangeHint hint);
 
    void _q_sourceRowsAboutToBeInserted(const QModelIndex &source_parent,
                                        int start, int end);
    void _q_sourceRowsInserted(const QModelIndex &source_parent,
                               int start, int end);
    void _q_sourceRowsAboutToBeRemoved(const QModelIndex &source_parent,
                                       int start, int end);
    void _q_sourceRowsRemoved(const QModelIndex &source_parent,
                              int start, int end);
    void _q_sourceRowsAboutToBeMoved(const QModelIndex &sourceParent,
                                     int sourceStart, int sourceEnd,
                                     const QModelIndex &destParent, int dest);
    void _q_sourceRowsMoved(const QModelIndex &sourceParent,
                            int sourceStart, int sourceEnd,
                            const QModelIndex &destParent, int dest);
    void _q_sourceColumnsAboutToBeInserted(const QModelIndex &source_parent,
                                           int start, int end);
    void _q_sourceColumnsInserted(const QModelIndex &source_parent,
                                  int start, int end);
    void _q_sourceColumnsAboutToBeRemoved(const QModelIndex &source_parent,
                                          int start, int end);
    void _q_sourceColumnsRemoved(const QModelIndex &source_parent,
                                 int start, int end);
    void _q_sourceColumnsAboutToBeMoved(const QModelIndex &sourceParent,
                                        int sourceStart, int sourceEnd,
                                        const QModelIndex &destParent, int dest);
    void _q_sourceColumnsMoved(const QModelIndex &sourceParent,
                               int sourceStart, int sourceEnd,
                               const QModelIndex &destParent, int dest);
 
    void _q_clearMapping();
 
    void sort();
    bool update_source_sort_column();
    int find_source_sort_column() const;
    void sort_source_rows(QList<int> &source_rows,
                          const QModelIndex &source_parent) const;
    QList<std::pair<int, QList<int>>> proxy_intervals_for_source_items_to_add(
        const QList<int> &proxy_to_source, const QList<int> &source_items,
        const QModelIndex &source_parent, Qt::Orientation orient) const;
    QList<std::pair<int, int>> proxy_intervals_for_source_items(
        const QList<int> &source_to_proxy, const QList<int> &source_items) const;
    void insert_source_items(
        QList<int> &source_to_proxy, QList<int> &proxy_to_source,
        const QList<int> &source_items, const QModelIndex &source_parent,
        Qt::Orientation orient, bool emit_signal = true);
    void remove_source_items(
        QList<int> &source_to_proxy, QList<int> &proxy_to_source,
        const QList<int> &source_items, const QModelIndex &source_parent,
        Qt::Orientation orient, bool emit_signal = true);
    void remove_proxy_interval(
        QList<int> &source_to_proxy, QList<int> &proxy_to_source,
        int proxy_start, int proxy_end, const QModelIndex &proxy_parent,
        Qt::Orientation orient, bool emit_signal = true);
    static inline void build_source_to_proxy_mapping(
        const QList<int> &proxy_to_source, QList<int> &source_to_proxy, int start = 0);
    void source_items_inserted(const QModelIndex &source_parent,
                               int start, int end, Qt::Orientation orient);
    void source_items_about_to_be_removed(const QModelIndex &source_parent,
                                          int start, int end, Qt::Orientation orient);
    void source_items_removed(const QModelIndex &source_parent,
                              int start, int end, Qt::Orientation orient);
    void proxy_item_range(
        const QList<int> &source_to_proxy, const QList<int> &source_items,
        int &proxy_low, int &proxy_high) const;
 
    QModelIndexPairList store_persistent_indexes() const;
    void update_persistent_indexes(const QModelIndexPairList &source_indexes);
 
    void filter_about_to_be_changed(const QModelIndex &source_parent = QModelIndex());
    void filter_changed(Direction dir, const QModelIndex &source_parent = QModelIndex());
    QSet<int> handle_filter_changed(
        QList<int> &source_to_proxy, QList<int> &proxy_to_source,
        const QModelIndex &source_parent, Qt::Orientation orient);
 
    void updateChildrenMapping(const QModelIndex &source_parent, Mapping *parent_mapping,
                               Qt::Orientation orient, int start, int end, int delta_item_count, bool remove);
 
    void _q_sourceModelDestroyed() override;
 
    bool needsReorder(const QList<int> &source_rows, const QModelIndex &source_parent) const;
 
    bool filterAcceptsRowInternal(int source_row, const QModelIndex &source_parent) const;
    bool recursiveChildAcceptsRow(int source_row, const QModelIndex &source_parent) const;
    bool recursiveParentAcceptsRow(const QModelIndex &source_parent) const;
};
 
typedef QHash<QModelIndex, QSortFilterProxyModelPrivate::Mapping *> IndexMap;
 
static bool operator&(QSortFilterProxyModelPrivate::Direction a, QSortFilterProxyModelPrivate::Direction b)
{
    return int(a) & int(b);
}
 
void QSortFilterProxyModelPrivate::_q_sourceModelDestroyed()
{
    QAbstractProxyModelPrivate::_q_sourceModelDestroyed();
    qDeleteAll(source_index_mapping);
    source_index_mapping.clear();
}
 
bool QSortFilterProxyModelPrivate::filterAcceptsRowInternal(int source_row, const QModelIndex &source_parent) const
{
    Q_Q(const QSortFilterProxyModel);
 
    if (q->filterAcceptsRow(source_row, source_parent))
        return true;
 
    // Go up the tree and accept this row if a parent is accepted
    if (accept_children && recursiveParentAcceptsRow(source_parent))
        return true;
 
    // Go down the tree and accept this row if a child is accepted
    if (filter_recursive && recursiveChildAcceptsRow(source_row, source_parent))
        return true;
 
    return false;
}
 
bool QSortFilterProxyModelPrivate::recursiveParentAcceptsRow(const QModelIndex &source_parent) const
{
    Q_Q(const QSortFilterProxyModel);
 
    if (source_parent.isValid()) {
        const QModelIndex index = source_parent.parent();
 
        if (q->filterAcceptsRow(source_parent.row(), index))
            return true;
 
        return recursiveParentAcceptsRow(index);
    }
 
    return false;
}
 
bool QSortFilterProxyModelPrivate::recursiveChildAcceptsRow(int source_row, const QModelIndex &source_parent) const
{
    Q_Q(const QSortFilterProxyModel);
 
    const QModelIndex index = model->index(source_row, 0, source_parent);
    const int count = model->rowCount(index);
 
    for (int i = 0; i < count; ++i) {
        if (q->filterAcceptsRow(i, index))
            return true;
 
        if (recursiveChildAcceptsRow(i, index))
            return true;
    }
 
    return false;
}
 
void QSortFilterProxyModelPrivate::remove_from_mapping(const QModelIndex &source_parent)
{
    if (Mapping *m = source_index_mapping.take(source_parent)) {
        for (const QModelIndex &mappedIdx : std::as_const(m->mapped_children))
            remove_from_mapping(mappedIdx);
        delete m;
    }
}
 
void QSortFilterProxyModelPrivate::_q_clearMapping()
{
    // store the persistent indexes
    QModelIndexPairList source_indexes = store_persistent_indexes();
 
    qDeleteAll(source_index_mapping);
    source_index_mapping.clear();
    if (dynamic_sortfilter)
        source_sort_column = find_source_sort_column();
 
    // update the persistent indexes
    update_persistent_indexes(source_indexes);
}
 
IndexMap::const_iterator QSortFilterProxyModelPrivate::create_mapping(
    const QModelIndex &source_parent) const
{
    Q_Q(const QSortFilterProxyModel);
 
    IndexMap::const_iterator it = source_index_mapping.constFind(source_parent);
    if (it != source_index_mapping.constEnd()) // was mapped already
        return it;
 
    Mapping *m = new Mapping;
 
    int source_rows = model->rowCount(source_parent);
    m->source_rows.reserve(source_rows);
    for (int i = 0; i < source_rows; ++i) {
        if (filterAcceptsRowInternal(i, source_parent))
            m->source_rows.append(i);
    }
    int source_cols = model->columnCount(source_parent);
    m->source_columns.reserve(source_cols);
    for (int i = 0; i < source_cols; ++i) {
        if (q->filterAcceptsColumn(i, source_parent))
            m->source_columns.append(i);
    }
 
    sort_source_rows(m->source_rows, source_parent);
    m->proxy_rows.resize(source_rows);
    build_source_to_proxy_mapping(m->source_rows, m->proxy_rows);
    m->proxy_columns.resize(source_cols);
    build_source_to_proxy_mapping(m->source_columns, m->proxy_columns);
 
    m->source_parent = source_parent;
 
    if (source_parent.isValid()) {
        QModelIndex source_grand_parent = source_parent.parent();
        IndexMap::const_iterator it2 = create_mapping(source_grand_parent);
        Q_ASSERT(it2 != source_index_mapping.constEnd());
        it2.value()->mapped_children.append(source_parent);
    }
 
    it = IndexMap::const_iterator(source_index_mapping.insert(source_parent, m));
    Q_ASSERT(it != source_index_mapping.constEnd());
    Q_ASSERT(it.value());
 
    return it;
}
 
// Go up the tree, creating mappings, unless of course the parent is filtered out
IndexMap::const_iterator QSortFilterProxyModelPrivate::create_mapping_recursive(const QModelIndex &source_parent) const
{
    if (source_parent.isValid()) {
        const QModelIndex source_grand_parent = source_parent.parent();
        IndexMap::const_iterator it = source_index_mapping.constFind(source_grand_parent);
        IndexMap::const_iterator end = source_index_mapping.constEnd();
        if (it == end) {
            it = create_mapping_recursive(source_grand_parent);
            end = source_index_mapping.constEnd();
            if (it == end)
                return end;
        }
        Mapping *gm = it.value();
        if (gm->proxy_rows.at(source_parent.row()) == -1 ||
                gm->proxy_columns.at(source_parent.column()) == -1) {
            // Can't do, parent is filtered
            return end;
        }
    }
    return create_mapping(source_parent);
}
 
QModelIndex QSortFilterProxyModelPrivate::proxy_to_source(const QModelIndex &proxy_index) const
{
    if (!proxy_index.isValid())
        return QModelIndex(); // for now; we may want to be able to set a root index later
    if (proxy_index.model() != q_func()) {
        qWarning("QSortFilterProxyModel: index from wrong model passed to mapToSource");
        Q_ASSERT(!"QSortFilterProxyModel: index from wrong model passed to mapToSource");
        return QModelIndex();
    }
    IndexMap::const_iterator it = index_to_iterator(proxy_index);
    Mapping *m = it.value();
    if ((proxy_index.row() >= m->source_rows.size()) || (proxy_index.column() >= m->source_columns.size()))
        return QModelIndex();
    int source_row = m->source_rows.at(proxy_index.row());
    int source_col = m->source_columns.at(proxy_index.column());
    return model->index(source_row, source_col, it.key());
}
 
QModelIndex QSortFilterProxyModelPrivate::source_to_proxy(const QModelIndex &source_index) const
{
    if (!source_index.isValid())
        return QModelIndex(); // for now; we may want to be able to set a root index later
    if (source_index.model() != model) {
        qWarning("QSortFilterProxyModel: index from wrong model passed to mapFromSource");
        Q_ASSERT(!"QSortFilterProxyModel: index from wrong model passed to mapFromSource");
        return QModelIndex();
    }
    QModelIndex source_parent = source_index.parent();
    IndexMap::const_iterator it = create_mapping(source_parent);
    Mapping *m = it.value();
    if ((source_index.row() >= m->proxy_rows.size()) || (source_index.column() >= m->proxy_columns.size()))
        return QModelIndex();
    int proxy_row = m->proxy_rows.at(source_index.row());
    int proxy_column = m->proxy_columns.at(source_index.column());
    if (proxy_row == -1 || proxy_column == -1)
        return QModelIndex();
    return create_index(proxy_row, proxy_column, it);
}
 
bool QSortFilterProxyModelPrivate::can_create_mapping(const QModelIndex &source_parent) const
{
    if (source_parent.isValid()) {
        QModelIndex source_grand_parent = source_parent.parent();
        IndexMap::const_iterator it = source_index_mapping.constFind(source_grand_parent);
        if (it == source_index_mapping.constEnd()) {
            // Don't care, since we don't have mapping for the grand parent
            return false;
        }
        Mapping *gm = it.value();
        if (gm->proxy_rows.at(source_parent.row()) == -1 ||
            gm->proxy_columns.at(source_parent.column()) == -1) {
            // Don't care, since parent is filtered
            return false;
        }
    }
    return true;
}
 
void QSortFilterProxyModelPrivate::sort()
{
    Q_Q(QSortFilterProxyModel);
    emit q->layoutAboutToBeChanged(QList<QPersistentModelIndex>(), QAbstractItemModel::VerticalSortHint);
    QModelIndexPairList source_indexes = store_persistent_indexes();
    const auto end = source_index_mapping.constEnd();
    for (auto it = source_index_mapping.constBegin(); it != end; ++it) {
        const QModelIndex &source_parent = it.key();
        Mapping *m = it.value();
        sort_source_rows(m->source_rows, source_parent);
        build_source_to_proxy_mapping(m->source_rows, m->proxy_rows);
    }
    update_persistent_indexes(source_indexes);
    emit q->layoutChanged(QList<QPersistentModelIndex>(), QAbstractItemModel::VerticalSortHint);
}
 
bool QSortFilterProxyModelPrivate::update_source_sort_column()
{
    int old_source_sort_column = source_sort_column;
 
    if (proxy_sort_column == -1) {
        source_sort_column = -1;
    } else {
        // We cannot use index mapping here because in case of a still-empty
        // proxy model there's no valid proxy index we could map to source.
        // So always use the root mapping directly instead.
        Mapping *m = create_mapping(QModelIndex()).value();
        if (proxy_sort_column < m->source_columns.size())
            source_sort_column = m->source_columns.at(proxy_sort_column);
        else
            source_sort_column = -1;
    }
 
    return old_source_sort_column != source_sort_column;
}
 
int QSortFilterProxyModelPrivate::find_source_sort_column() const
{
    if (proxy_sort_column == -1)
        return -1;
 
    const QModelIndex rootIndex;
    const int source_cols = model->columnCount();
    int accepted_columns = -1;
 
    Q_Q(const QSortFilterProxyModel);
    for (int i = 0; i < source_cols; ++i) {
        if (q->filterAcceptsColumn(i, rootIndex)) {
            if (++accepted_columns == proxy_sort_column)
                return i;
        }
    }
 
    return -1;
}
 
void QSortFilterProxyModelPrivate::sort_source_rows(
    QList<int> &source_rows, const QModelIndex &source_parent) const
{
    Q_Q(const QSortFilterProxyModel);
    if (source_sort_column >= 0) {
        if (sort_order == Qt::AscendingOrder) {
            QSortFilterProxyModelLessThan lt(source_sort_column, source_parent, model, q);
            std::stable_sort(source_rows.begin(), source_rows.end(), lt);
        } else {
            QSortFilterProxyModelGreaterThan gt(source_sort_column, source_parent, model, q);
            std::stable_sort(source_rows.begin(), source_rows.end(), gt);
        }
    } else if (sort_order == Qt::AscendingOrder) {
        std::stable_sort(source_rows.begin(), source_rows.end(), std::less{});
    } else {
        std::stable_sort(source_rows.begin(), source_rows.end(), std::greater{});
    }
}
 
QList<std::pair<int, int>> QSortFilterProxyModelPrivate::proxy_intervals_for_source_items(
    const QList<int> &source_to_proxy, const QList<int> &source_items) const
{
    QList<std::pair<int, int>> proxy_intervals;
    if (source_items.isEmpty())
        return proxy_intervals;
 
    int source_items_index = 0;
    while (source_items_index < source_items.size()) {
        int first_proxy_item = source_to_proxy.at(source_items.at(source_items_index));
        Q_ASSERT(first_proxy_item != -1);
        int last_proxy_item = first_proxy_item;
        ++source_items_index;
        // Find end of interval
        while ((source_items_index < source_items.size())
               && (source_to_proxy.at(source_items.at(source_items_index)) == last_proxy_item + 1)) {
            ++last_proxy_item;
            ++source_items_index;
        }
        // Add interval to result
        proxy_intervals.emplace_back(first_proxy_item, last_proxy_item);
    }
    std::stable_sort(proxy_intervals.begin(), proxy_intervals.end());
    // Consolidate adjacent intervals
    for (int i = proxy_intervals.size()-1; i > 0; --i) {
        std::pair<int, int> &interval = proxy_intervals[i];
        std::pair<int, int> &preceeding_interval = proxy_intervals[i - 1];
        if (interval.first == preceeding_interval.second + 1) {
            preceeding_interval.second = interval.second;
            interval.first = interval.second = -1;
        }
    }
    proxy_intervals.removeIf([](std::pair<int, int> interval) { return interval.first < 0; });
    return proxy_intervals;
}
 
void QSortFilterProxyModelPrivate::remove_source_items(
    QList<int> &source_to_proxy, QList<int> &proxy_to_source,
    const QList<int> &source_items, const QModelIndex &source_parent,
    Qt::Orientation orient, bool emit_signal)
{
    Q_Q(QSortFilterProxyModel);
    QModelIndex proxy_parent = q->mapFromSource(source_parent);
    if (!proxy_parent.isValid() && source_parent.isValid()) {
        proxy_to_source.clear();
        return; // nothing to do (already removed)
    }
 
    const auto proxy_intervals = proxy_intervals_for_source_items(
        source_to_proxy, source_items);
 
    const auto end = proxy_intervals.rend();
    for (auto it = proxy_intervals.rbegin(); it != end; ++it) {
        const std::pair<int, int> &interval = *it;
        const int proxy_start = interval.first;
        const int proxy_end = interval.second;
        remove_proxy_interval(source_to_proxy, proxy_to_source, proxy_start, proxy_end,
                              proxy_parent, orient, emit_signal);
    }
}
 
void QSortFilterProxyModelPrivate::remove_proxy_interval(
    QList<int> &source_to_proxy, QList<int> &proxy_to_source, int proxy_start, int proxy_end,
    const QModelIndex &proxy_parent, Qt::Orientation orient, bool emit_signal)
{
    Q_Q(QSortFilterProxyModel);
    if (emit_signal) {
        if (orient == Qt::Vertical)
            q->beginRemoveRows(proxy_parent, proxy_start, proxy_end);
        else
            q->beginRemoveColumns(proxy_parent, proxy_start, proxy_end);
    }
 
    // Remove items from proxy-to-source mapping
    for (int i = proxy_start; i <= proxy_end; ++i)
        source_to_proxy[proxy_to_source.at(i)] = -1;
    proxy_to_source.remove(proxy_start, proxy_end - proxy_start + 1);
 
    build_source_to_proxy_mapping(proxy_to_source, source_to_proxy, proxy_start);
 
    if (emit_signal) {
        if (orient == Qt::Vertical)
            q->endRemoveRows();
        else
            q->endRemoveColumns();
    }
}
 
QList<std::pair<int, QList<int>>> QSortFilterProxyModelPrivate::proxy_intervals_for_source_items_to_add(
    const QList<int> &proxy_to_source, const QList<int> &source_items,
    const QModelIndex &source_parent, Qt::Orientation orient) const
{
    Q_Q(const QSortFilterProxyModel);
    QList<std::pair<int, QList<int>>> proxy_intervals;
    if (source_items.isEmpty())
        return proxy_intervals;
 
    int proxy_low = 0;
    int proxy_item = 0;
    int source_items_index = 0;
    bool compare = (orient == Qt::Vertical && source_sort_column >= 0 && dynamic_sortfilter);
    while (source_items_index < source_items.size()) {
        QList<int> source_items_in_interval;
        int first_new_source_item = source_items.at(source_items_index);
        source_items_in_interval.append(first_new_source_item);
        ++source_items_index;
 
        // Find proxy item at which insertion should be started
        int proxy_high = proxy_to_source.size() - 1;
        QModelIndex i1 = compare ? model->index(first_new_source_item, source_sort_column, source_parent) : QModelIndex();
        while (proxy_low <= proxy_high) {
            proxy_item = (proxy_low + proxy_high) / 2;
            if (compare) {
                QModelIndex i2 = model->index(proxy_to_source.at(proxy_item), source_sort_column, source_parent);
                if ((sort_order == Qt::AscendingOrder) ? q->lessThan(i1, i2) : q->lessThan(i2, i1))
                    proxy_high = proxy_item - 1;
                else
                    proxy_low = proxy_item + 1;
            } else {
                if (first_new_source_item < proxy_to_source.at(proxy_item))
                    proxy_high = proxy_item - 1;
                else
                    proxy_low = proxy_item + 1;
            }
        }
        proxy_item = proxy_low;
 
        // Find the sequence of new source items that should be inserted here
        if (proxy_item >= proxy_to_source.size()) {
            for ( ; source_items_index < source_items.size(); ++source_items_index)
                source_items_in_interval.append(source_items.at(source_items_index));
        } else {
            i1 = compare ? model->index(proxy_to_source.at(proxy_item), source_sort_column, source_parent) : QModelIndex();
            for ( ; source_items_index < source_items.size(); ++source_items_index) {
                int new_source_item = source_items.at(source_items_index);
                if (compare) {
                    QModelIndex i2 = model->index(new_source_item, source_sort_column, source_parent);
                    if ((sort_order == Qt::AscendingOrder) ? q->lessThan(i1, i2) : q->lessThan(i2, i1))
                        break;
                } else {
                    if (proxy_to_source.at(proxy_item) < new_source_item)
                        break;
                }
                source_items_in_interval.append(new_source_item);
            }
        }
 
        // Add interval to result
        proxy_intervals.emplace_back(proxy_item, std::move(source_items_in_interval));
    }
    return proxy_intervals;
}
 
void QSortFilterProxyModelPrivate::insert_source_items(
    QList<int> &source_to_proxy, QList<int> &proxy_to_source,
    const QList<int> &source_items, const QModelIndex &source_parent,
    Qt::Orientation orient, bool emit_signal)
{
    Q_Q(QSortFilterProxyModel);
    QModelIndex proxy_parent = q->mapFromSource(source_parent);
    if (!proxy_parent.isValid() && source_parent.isValid())
        return; // nothing to do (source_parent is not mapped)
 
    const auto proxy_intervals = proxy_intervals_for_source_items_to_add(
        proxy_to_source, source_items, source_parent, orient);
 
    const auto end = proxy_intervals.rend();
    for (auto it = proxy_intervals.rbegin(); it != end; ++it) {
        const std::pair<int, QList<int>> &interval = *it;
        const int proxy_start = interval.first;
        const QList<int> &source_items = interval.second;
        const int proxy_end = proxy_start + source_items.size() - 1;
 
        if (emit_signal) {
            if (orient == Qt::Vertical)
                q->beginInsertRows(proxy_parent, proxy_start, proxy_end);
            else
                q->beginInsertColumns(proxy_parent, proxy_start, proxy_end);
        }
 
        // TODO: use the range QList::insert() overload once it is implemented (QTBUG-58633).
        proxy_to_source.insert(proxy_start, source_items.size(), 0);
        std::copy(source_items.cbegin(), source_items.cend(), proxy_to_source.begin() + proxy_start);
 
        build_source_to_proxy_mapping(proxy_to_source, source_to_proxy, proxy_start);
 
        if (emit_signal) {
            if (orient == Qt::Vertical)
                q->endInsertRows();
            else
                q->endInsertColumns();
        }
    }
}
 
void QSortFilterProxyModelPrivate::source_items_inserted(
    const QModelIndex &source_parent, int start, int end, Qt::Orientation orient)
{
    Q_Q(QSortFilterProxyModel);
    if ((start < 0) || (end < 0))
        return;
    IndexMap::const_iterator it = source_index_mapping.constFind(source_parent);
    if (it == source_index_mapping.constEnd()) {
        if (!can_create_mapping(source_parent))
            return;
        it = create_mapping(source_parent);
        Mapping *m = it.value();
        QModelIndex proxy_parent = q->mapFromSource(source_parent);
        if (m->source_rows.size() > 0) {
            q->beginInsertRows(proxy_parent, 0, m->source_rows.size() - 1);
            q->endInsertRows();
        }
        if (m->source_columns.size() > 0) {
            q->beginInsertColumns(proxy_parent, 0, m->source_columns.size() - 1);
            q->endInsertColumns();
        }
        return;
    }
 
    Mapping *m = it.value();
    QList<int> &source_to_proxy = (orient == Qt::Vertical) ? m->proxy_rows : m->proxy_columns;
    QList<int> &proxy_to_source = (orient == Qt::Vertical) ? m->source_rows : m->source_columns;
 
    int delta_item_count = end - start + 1;
    int old_item_count = source_to_proxy.size();
 
    updateChildrenMapping(source_parent, m, orient, start, end, delta_item_count, false);
 
    // Expand source-to-proxy mapping to account for new items
    if (start < 0 || start > source_to_proxy.size()) {
        qWarning("QSortFilterProxyModel: invalid inserted rows reported by source model");
        remove_from_mapping(source_parent);
        return;
    }
    source_to_proxy.insert(start, delta_item_count, -1);
 
    if (start < old_item_count) {
        // Adjust existing "stale" indexes in proxy-to-source mapping
        int proxy_count = proxy_to_source.size();
        for (int proxy_item = 0; proxy_item < proxy_count; ++proxy_item) {
            int source_item = proxy_to_source.at(proxy_item);
            if (source_item >= start)
                proxy_to_source.replace(proxy_item, source_item + delta_item_count);
        }
        build_source_to_proxy_mapping(proxy_to_source, source_to_proxy);
    }
 
    // Figure out which items to add to mapping based on filter
    QList<int> source_items;
    for (int i = start; i <= end; ++i) {
        if ((orient == Qt::Vertical)
            ? filterAcceptsRowInternal(i, source_parent)
            : q->filterAcceptsColumn(i, source_parent)) {
            source_items.append(i);
        }
    }
 
    if (model->rowCount(source_parent) == delta_item_count) {
        // Items were inserted where there were none before.
        // If it was new rows make sure to create mappings for columns so that a
        // valid mapping can be retrieved later and vice-versa.
 
        QList<int> &orthogonal_proxy_to_source = (orient == Qt::Horizontal) ? m->source_rows : m->source_columns;
        QList<int> &orthogonal_source_to_proxy = (orient == Qt::Horizontal) ? m->proxy_rows : m->proxy_columns;
 
        if (orthogonal_source_to_proxy.isEmpty()) {
            const int ortho_end = (orient == Qt::Horizontal) ? model->rowCount(source_parent) : model->columnCount(source_parent);
 
            orthogonal_source_to_proxy.resize(ortho_end);
 
            for (int ortho_item = 0; ortho_item < ortho_end; ++ortho_item) {
                if ((orient == Qt::Horizontal) ? filterAcceptsRowInternal(ortho_item, source_parent)
                        : q->filterAcceptsColumn(ortho_item, source_parent)) {
                    orthogonal_proxy_to_source.append(ortho_item);
                }
            }
            if (orient == Qt::Horizontal) {
                // We're reacting to columnsInserted, but we've just inserted new rows. Sort them.
                sort_source_rows(orthogonal_proxy_to_source, source_parent);
            }
            build_source_to_proxy_mapping(orthogonal_proxy_to_source, orthogonal_source_to_proxy);
        }
    }
 
    // Sort and insert the items
    if (orient == Qt::Vertical) // Only sort rows
        sort_source_rows(source_items, source_parent);
    insert_source_items(source_to_proxy, proxy_to_source, source_items, source_parent, orient);
}
 
void QSortFilterProxyModelPrivate::source_items_about_to_be_removed(
    const QModelIndex &source_parent, int start, int end, Qt::Orientation orient)
{
    if ((start < 0) || (end < 0))
        return;
    IndexMap::const_iterator it = source_index_mapping.constFind(source_parent);
    if (it == source_index_mapping.constEnd()) {
        // Don't care, since we don't have mapping for this index
        return;
    }
 
    Mapping *m = it.value();
    QList<int> &source_to_proxy = (orient == Qt::Vertical) ? m->proxy_rows : m->proxy_columns;
    QList<int> &proxy_to_source = (orient == Qt::Vertical) ? m->source_rows : m->source_columns;
 
    // figure out which items to remove
    QList<int> source_items_to_remove;
    int proxy_count = proxy_to_source.size();
    for (int proxy_item = 0; proxy_item < proxy_count; ++proxy_item) {
        int source_item = proxy_to_source.at(proxy_item);
        if ((source_item >= start) && (source_item <= end))
            source_items_to_remove.append(source_item);
    }
 
    remove_source_items(source_to_proxy, proxy_to_source, source_items_to_remove,
                        source_parent, orient);
}
 
void QSortFilterProxyModelPrivate::source_items_removed(
    const QModelIndex &source_parent, int start, int end, Qt::Orientation orient)
{
    if ((start < 0) || (end < 0))
        return;
    IndexMap::const_iterator it = source_index_mapping.constFind(source_parent);
    if (it == source_index_mapping.constEnd()) {
        // Don't care, since we don't have mapping for this index
        return;
    }
 
    Mapping *m = it.value();
    QList<int> &source_to_proxy = (orient == Qt::Vertical) ? m->proxy_rows : m->proxy_columns;
    QList<int> &proxy_to_source = (orient == Qt::Vertical) ? m->source_rows : m->source_columns;
 
    if (end >= source_to_proxy.size())
        end = source_to_proxy.size() - 1;
 
    // Shrink the source-to-proxy mapping to reflect the new item count
    int delta_item_count = end - start + 1;
    source_to_proxy.remove(start, delta_item_count);
 
    int proxy_count = proxy_to_source.size();
    if (proxy_count > source_to_proxy.size()) {
        // mapping is in an inconsistent state -- redo the whole mapping
        qWarning("QSortFilterProxyModel: inconsistent changes reported by source model");
        Q_Q(QSortFilterProxyModel);
        q->beginResetModel();
        remove_from_mapping(source_parent);
        q->endResetModel();
        return;
    }
 
    // Adjust "stale" indexes in proxy-to-source mapping
    for (int proxy_item = 0; proxy_item < proxy_count; ++proxy_item) {
        int source_item = proxy_to_source.at(proxy_item);
        if (source_item >= start) {
            Q_ASSERT(source_item - delta_item_count >= 0);
            proxy_to_source.replace(proxy_item, source_item - delta_item_count);
        }
    }
    build_source_to_proxy_mapping(proxy_to_source, source_to_proxy);
 
    updateChildrenMapping(source_parent, m, orient, start, end, delta_item_count, true);
 
}
 
 
void QSortFilterProxyModelPrivate::updateChildrenMapping(const QModelIndex &source_parent, Mapping *parent_mapping,
                                                         Qt::Orientation orient, int start, int end, int delta_item_count, bool remove)
{
    // see if any mapped children should be (re)moved
    QList<std::pair<QModelIndex, Mapping *>> moved_source_index_mappings;
    auto it2 = parent_mapping->mapped_children.begin();
    for ( ; it2 != parent_mapping->mapped_children.end();) {
        const QModelIndex source_child_index = *it2;
        const int pos = (orient == Qt::Vertical)
                        ? source_child_index.row()
                        : source_child_index.column();
        if (pos < start) {
            // not affected
            ++it2;
        } else if (remove && pos <= end) {
            // in the removed interval
            it2 = parent_mapping->mapped_children.erase(it2);
            remove_from_mapping(source_child_index);
        } else {
            // below the removed items -- recompute the index
            QModelIndex new_index;
            const int newpos = remove ? pos - delta_item_count : pos + delta_item_count;
            if (orient == Qt::Vertical) {
                new_index = model->index(newpos,
                                         source_child_index.column(),
                                         source_parent);
            } else {
                new_index = model->index(source_child_index.row(),
                                         newpos,
                                         source_parent);
            }
            *it2 = new_index;
            ++it2;
 
            // update mapping
            Mapping *cm = source_index_mapping.take(source_child_index);
            Q_ASSERT(cm);
            // we do not reinsert right away, because the new index might be identical with another, old index
            moved_source_index_mappings.emplace_back(new_index, cm);
        }
    }
 
    // reinsert moved, mapped indexes
    for (auto &pair : std::as_const(moved_source_index_mappings)) {
        pair.second->source_parent = pair.first;
        source_index_mapping.insert(pair.first, pair.second);
    }
}
 
void QSortFilterProxyModelPrivate::proxy_item_range(
    const QList<int> &source_to_proxy, const QList<int> &source_items,
    int &proxy_low, int &proxy_high) const
{
    proxy_low = INT_MAX;
    proxy_high = INT_MIN;
    for (int i = 0; i < source_items.size(); ++i) {
        int proxy_item = source_to_proxy.at(source_items.at(i));
        Q_ASSERT(proxy_item != -1);
        if (proxy_item < proxy_low)
            proxy_low = proxy_item;
        if (proxy_item > proxy_high)
            proxy_high = proxy_item;
    }
}
 
void QSortFilterProxyModelPrivate::build_source_to_proxy_mapping(
    const QList<int> &proxy_to_source, QList<int> &source_to_proxy, int start)
{
    if (start == 0)
        source_to_proxy.fill(-1);
    const int proxy_count = proxy_to_source.size();
    for (int i = start; i < proxy_count; ++i)
        source_to_proxy[proxy_to_source.at(i)] = i;
}
 
QModelIndexPairList QSortFilterProxyModelPrivate::store_persistent_indexes() const
{
    Q_Q(const QSortFilterProxyModel);
    QModelIndexPairList source_indexes;
    source_indexes.reserve(persistent.indexes.size());
    for (const QPersistentModelIndexData *data : std::as_const(persistent.indexes)) {
        const QModelIndex &proxy_index = data->index;
        QModelIndex source_index = q->mapToSource(proxy_index);
        source_indexes.emplace_back(proxy_index, source_index);
    }
    return source_indexes;
}
 
void QSortFilterProxyModelPrivate::update_persistent_indexes(
        const QModelIndexPairList &source_indexes)
{
    Q_Q(QSortFilterProxyModel);
    QModelIndexList from, to;
    const int numSourceIndexes = source_indexes.size();
    from.reserve(numSourceIndexes);
    to.reserve(numSourceIndexes);
    for (const auto &indexPair : source_indexes) {
        const QPersistentModelIndex &source_index = indexPair.second;
        const QModelIndex &old_proxy_index = indexPair.first;
        create_mapping(source_index.parent());
        QModelIndex proxy_index = q->mapFromSource(source_index);
        from << old_proxy_index;
        to << proxy_index;
    }
    q->changePersistentIndexList(from, to);
}
 
void QSortFilterProxyModelPrivate::filter_about_to_be_changed(const QModelIndex &source_parent)
{
    if (!filter_regularexpression.valueBypassingBindings().pattern().isEmpty()
        && source_index_mapping.constFind(source_parent) == source_index_mapping.constEnd()) {
        create_mapping(source_parent);
    }
}
 
 
void QSortFilterProxyModelPrivate::filter_changed(Direction dir, const QModelIndex &source_parent)
{
    IndexMap::const_iterator it = source_index_mapping.constFind(source_parent);
    if (it == source_index_mapping.constEnd())
        return;
    Mapping *m = it.value();
    const QSet<int> rows_removed = (dir & Direction::Rows) ? handle_filter_changed(m->proxy_rows, m->source_rows, source_parent, Qt::Vertical) : QSet<int>();
    const QSet<int> columns_removed = (dir & Direction::Columns) ? handle_filter_changed(m->proxy_columns, m->source_columns, source_parent, Qt::Horizontal) : QSet<int>();
 
    // We need to iterate over a copy of m->mapped_children because otherwise it may be changed by other code, invalidating
    // the iterator it2.
    // The m->mapped_children vector can be appended to with indexes which are no longer filtered
    // out (in create_mapping) when this function recurses for child indexes.
    const QList<QModelIndex> mappedChildren = m->mapped_children;
    QList<int> indexesToRemove;
    for (int i = 0; i < mappedChildren.size(); ++i) {
        const QModelIndex &source_child_index = mappedChildren.at(i);
        if (rows_removed.contains(source_child_index.row()) || columns_removed.contains(source_child_index.column())) {
            indexesToRemove.push_back(i);
            remove_from_mapping(source_child_index);
        } else {
            filter_changed(dir, source_child_index);
        }
    }
    QList<int>::const_iterator removeIt = indexesToRemove.constEnd();
    const QList<int>::const_iterator removeBegin = indexesToRemove.constBegin();
 
    // We can't just remove these items from mappedChildren while iterating above and then
    // do something like m->mapped_children = mappedChildren, because mapped_children might
    // be appended to in create_mapping, and we would lose those new items.
    // Because they are always appended in create_mapping, we can still remove them by
    // position here.
    while (removeIt != removeBegin) {
        --removeIt;
        m->mapped_children.remove(*removeIt);
    }
}
 
QSet<int> QSortFilterProxyModelPrivate::handle_filter_changed(
    QList<int> &source_to_proxy, QList<int> &proxy_to_source,
    const QModelIndex &source_parent, Qt::Orientation orient)
{
    Q_Q(QSortFilterProxyModel);
    // Figure out which mapped items to remove
    QList<int> source_items_remove;
    for (int i = 0; i < proxy_to_source.size(); ++i) {
        const int source_item = proxy_to_source.at(i);
        if ((orient == Qt::Vertical)
            ? !filterAcceptsRowInternal(source_item, source_parent)
            : !q->filterAcceptsColumn(source_item, source_parent)) {
            // This source item does not satisfy the filter, so it must be removed
            source_items_remove.append(source_item);
        }
    }
    // Figure out which non-mapped items to insert
    QList<int> source_items_insert;
    int source_count = source_to_proxy.size();
    for (int source_item = 0; source_item < source_count; ++source_item) {
        if (source_to_proxy.at(source_item) == -1) {
            if ((orient == Qt::Vertical)
                ? filterAcceptsRowInternal(source_item, source_parent)
                : q->filterAcceptsColumn(source_item, source_parent)) {
                // This source item satisfies the filter, so it must be added
                source_items_insert.append(source_item);
            }
        }
    }
    if (!source_items_remove.isEmpty() || !source_items_insert.isEmpty()) {
        // Do item removal and insertion
        remove_source_items(source_to_proxy, proxy_to_source,
                            source_items_remove, source_parent, orient);
        if (orient == Qt::Vertical)
            sort_source_rows(source_items_insert, source_parent);
        insert_source_items(source_to_proxy, proxy_to_source,
                            source_items_insert, source_parent, orient);
    }
    return qListToSet(source_items_remove);
}
 
bool QSortFilterProxyModelPrivate::needsReorder(const QList<int> &source_rows, const QModelIndex &source_parent) const
{
    Q_Q(const QSortFilterProxyModel);
    Q_ASSERT(source_sort_column != -1);
    const int proxyRowCount = q->rowCount(source_to_proxy(source_parent));
    // If any modified proxy row no longer passes lessThan(previous, current) or lessThan(current, next) then we need to reorder.
    return std::any_of(source_rows.begin(), source_rows.end(),
            [this, q, proxyRowCount, source_parent](int sourceRow) -> bool {
        const QModelIndex sourceIndex = model->index(sourceRow, source_sort_column, source_parent);
        const QModelIndex proxyIndex = source_to_proxy(sourceIndex);
        Q_ASSERT(proxyIndex.isValid()); // caller ensured source_rows were not filtered out
        if (proxyIndex.row() > 0) {
            const QModelIndex prevProxyIndex = q->sibling(proxyIndex.row() - 1, proxy_sort_column, proxyIndex);
            const QModelIndex prevSourceIndex = proxy_to_source(prevProxyIndex);
            if (sort_order == Qt::AscendingOrder ? q->lessThan(sourceIndex, prevSourceIndex) : q->lessThan(prevSourceIndex, sourceIndex))
                return true;
        }
        if (proxyIndex.row() < proxyRowCount - 1) {
            const QModelIndex nextProxyIndex = q->sibling(proxyIndex.row() + 1, proxy_sort_column, proxyIndex);
            const QModelIndex nextSourceIndex = proxy_to_source(nextProxyIndex);
            if (sort_order == Qt::AscendingOrder ? q->lessThan(nextSourceIndex, sourceIndex) : q->lessThan(sourceIndex, nextSourceIndex))
                return true;
        }
        return false;
    });
}
 
void QSortFilterProxyModelPrivate::_q_sourceDataChanged(const QModelIndex &source_top_left,
                                                        const QModelIndex &source_bottom_right,
                                                        const QList<int> &roles)
{
    Q_Q(QSortFilterProxyModel);
    if (!source_top_left.isValid() || !source_bottom_right.isValid())
        return;
 
    std::vector<QSortFilterProxyModelDataChanged> data_changed_list;
    data_changed_list.emplace_back(source_top_left, source_bottom_right);
 
    // Do check parents if the filter role have changed and we are recursive
    if (filter_recursive && (roles.isEmpty() || roles.contains(filter_role))) {
        QModelIndex source_parent = source_top_left.parent();
 
        while (source_parent.isValid()) {
            data_changed_list.emplace_back(source_parent, source_parent);
            source_parent = source_parent.parent();
        }
    }
 
    for (const QSortFilterProxyModelDataChanged &data_changed : data_changed_list) {
        const QModelIndex &source_top_left = data_changed.topLeft;
        const QModelIndex &source_bottom_right = data_changed.bottomRight;
        const QModelIndex source_parent = source_top_left.parent();
 
        bool change_in_unmapped_parent = false;
        IndexMap::const_iterator it = source_index_mapping.constFind(source_parent);
        if (it == source_index_mapping.constEnd()) {
            // We don't have mapping for this index, so we cannot know how things
            // changed (in case the change affects filtering) in order to forward
            // the change correctly.
            // But we can at least forward the signal "as is", if the row isn't
            // filtered out, this is better than nothing.
            it = create_mapping_recursive(source_parent);
            if (it == source_index_mapping.constEnd())
                continue;
            change_in_unmapped_parent = true;
        }
 
        Mapping *m = it.value();
 
        // Figure out how the source changes affect us
        QList<int> source_rows_remove;
        QList<int> source_rows_insert;
        QList<int> source_rows_change;
        QList<int> source_rows_resort;
        int end = qMin(source_bottom_right.row(), m->proxy_rows.size() - 1);
        for (int source_row = source_top_left.row(); source_row <= end; ++source_row) {
            if (dynamic_sortfilter && !change_in_unmapped_parent) {
                if (m->proxy_rows.at(source_row) != -1) {
                    if (!filterAcceptsRowInternal(source_row, source_parent)) {
                        // This source row no longer satisfies the filter, so it must be removed
                        source_rows_remove.append(source_row);
                    } else if (source_sort_column >= source_top_left.column() && source_sort_column <= source_bottom_right.column()) {
                        // This source row has changed in a way that may affect sorted order
                        source_rows_resort.append(source_row);
                    } else {
                        // This row has simply changed, without affecting filtering nor sorting
                        source_rows_change.append(source_row);
                    }
                } else {
                    if (!itemsBeingRemoved.contains(source_parent, source_row) && filterAcceptsRowInternal(source_row, source_parent)) {
                        // This source row now satisfies the filter, so it must be added
                        source_rows_insert.append(source_row);
                    }
                }
            } else {
                if (m->proxy_rows.at(source_row) != -1)
                    source_rows_change.append(source_row);
            }
        }
 
        if (!source_rows_remove.isEmpty()) {
            remove_source_items(m->proxy_rows, m->source_rows,
                                source_rows_remove, source_parent, Qt::Vertical);
            QSet<int> source_rows_remove_set = qListToSet(source_rows_remove);
            QList<QModelIndex>::iterator childIt = m->mapped_children.end();
            while (childIt != m->mapped_children.begin()) {
                --childIt;
                const QModelIndex source_child_index = *childIt;
                if (source_rows_remove_set.contains(source_child_index.row())) {
                    childIt = m->mapped_children.erase(childIt);
                    remove_from_mapping(source_child_index);
                }
            }
        }
 
        if (!source_rows_resort.isEmpty()) {
            if (needsReorder(source_rows_resort, source_parent)) {
                // Re-sort the rows of this level
                QList<QPersistentModelIndex> parents;
                parents << q->mapFromSource(source_parent);
                emit q->layoutAboutToBeChanged(parents, QAbstractItemModel::VerticalSortHint);
                QModelIndexPairList source_indexes = store_persistent_indexes();
                remove_source_items(m->proxy_rows, m->source_rows, source_rows_resort,
                        source_parent, Qt::Vertical, false);
                sort_source_rows(source_rows_resort, source_parent);
                insert_source_items(m->proxy_rows, m->source_rows, source_rows_resort,
                        source_parent, Qt::Vertical, false);
                update_persistent_indexes(source_indexes);
                emit q->layoutChanged(parents, QAbstractItemModel::VerticalSortHint);
            }
            // Make sure we also emit dataChanged for the rows
            source_rows_change += source_rows_resort;
        }
 
        if (!source_rows_change.isEmpty()) {
            // Find the proxy row range
            int proxy_start_row;
            int proxy_end_row;
            proxy_item_range(m->proxy_rows, source_rows_change,
                             proxy_start_row, proxy_end_row);
            // ### Find the proxy column range also
            if (proxy_end_row >= 0) {
                // the row was accepted, but some columns might still be filtered out
                int source_left_column = source_top_left.column();
                while (source_left_column < source_bottom_right.column()
                       && m->proxy_columns.at(source_left_column) == -1)
                    ++source_left_column;
                if (m->proxy_columns.at(source_left_column) != -1) {
                    const QModelIndex proxy_top_left = create_index(
                        proxy_start_row, m->proxy_columns.at(source_left_column), it);
                    int source_right_column = source_bottom_right.column();
                    while (source_right_column > source_top_left.column()
                           && m->proxy_columns.at(source_right_column) == -1)
                        --source_right_column;
                    if (m->proxy_columns.at(source_right_column) != -1) {
                        const QModelIndex proxy_bottom_right = create_index(
                            proxy_end_row, m->proxy_columns.at(source_right_column), it);
                        emit q->dataChanged(proxy_top_left, proxy_bottom_right, roles);
                    }
                }
            }
        }
 
        if (!source_rows_insert.isEmpty()) {
            sort_source_rows(source_rows_insert, source_parent);
            insert_source_items(m->proxy_rows, m->source_rows,
                                source_rows_insert, source_parent, Qt::Vertical);
        }
    }
}
 
void QSortFilterProxyModelPrivate::_q_sourceHeaderDataChanged(Qt::Orientation orientation,
                                                           int start, int end)
{
    Q_ASSERT(start <= end);
 
    Q_Q(QSortFilterProxyModel);
    Mapping *m = create_mapping(QModelIndex()).value();
 
    const QList<int> &source_to_proxy = (orientation == Qt::Vertical) ? m->proxy_rows : m->proxy_columns;
 
    QList<int> proxy_positions;
    proxy_positions.reserve(end - start + 1);
    {
        Q_ASSERT(source_to_proxy.size() > end);
        QList<int>::const_iterator it = source_to_proxy.constBegin() + start;
        const QList<int>::const_iterator endIt = source_to_proxy.constBegin() + end + 1;
        for ( ; it != endIt; ++it) {
            if (*it != -1)
                proxy_positions.push_back(*it);
        }
    }
 
    std::sort(proxy_positions.begin(), proxy_positions.end());
 
    int last_index = 0;
    const int numItems = proxy_positions.size();
    while (last_index < numItems) {
        const int proxyStart = proxy_positions.at(last_index);
        int proxyEnd = proxyStart;
        ++last_index;
        for (int i = last_index; i < numItems; ++i) {
            if (proxy_positions.at(i) == proxyEnd + 1) {
                ++last_index;
                ++proxyEnd;
            } else {
                break;
            }
        }
        emit q->headerDataChanged(orientation, proxyStart, proxyEnd);
    }
}
 
void QSortFilterProxyModelPrivate::_q_sourceAboutToBeReset()
{
    Q_Q(QSortFilterProxyModel);
    q->beginResetModel();
}
 
void QSortFilterProxyModelPrivate::_q_sourceReset()
{
    Q_Q(QSortFilterProxyModel);
    invalidatePersistentIndexes();
    _q_clearMapping();
    // All internal structures are deleted in clear()
    q->endResetModel();
    if (update_source_sort_column() && dynamic_sortfilter)
        sort();
}
 
void QSortFilterProxyModelPrivate::_q_sourceLayoutAboutToBeChanged(const QList<QPersistentModelIndex> &sourceParents, QAbstractItemModel::LayoutChangeHint hint)
{
    Q_Q(QSortFilterProxyModel);
    Q_UNUSED(hint); // We can't forward Hint because we might filter additional rows or columns
    saved_persistent_indexes.clear();
 
    saved_layoutChange_parents.clear();
    for (const QPersistentModelIndex &parent : sourceParents) {
        if (!parent.isValid()) {
            saved_layoutChange_parents << QPersistentModelIndex();
            continue;
        }
        const QModelIndex mappedParent = q->mapFromSource(parent);
        // Might be filtered out.
        if (mappedParent.isValid())
            saved_layoutChange_parents << mappedParent;
    }
 
    // All parents filtered out.
    if (!sourceParents.isEmpty() && saved_layoutChange_parents.isEmpty())
        return;
 
    emit q->layoutAboutToBeChanged(saved_layoutChange_parents);
    if (persistent.indexes.isEmpty())
        return;
 
    saved_persistent_indexes = store_persistent_indexes();
}
 
void QSortFilterProxyModelPrivate::_q_sourceLayoutChanged(const QList<QPersistentModelIndex> &sourceParents, QAbstractItemModel::LayoutChangeHint hint)
{
    Q_Q(QSortFilterProxyModel);
    Q_UNUSED(hint); // We can't forward Hint because we might filter additional rows or columns
 
    if (!sourceParents.isEmpty() && saved_layoutChange_parents.isEmpty())
        return;
 
    // Optimize: We only actually have to clear the mapping related to the contents of
    // sourceParents, not everything.
    qDeleteAll(source_index_mapping);
    source_index_mapping.clear();
 
    update_persistent_indexes(saved_persistent_indexes);
    saved_persistent_indexes.clear();
 
    if (dynamic_sortfilter)
        source_sort_column = find_source_sort_column();
 
    emit q->layoutChanged(saved_layoutChange_parents);
    saved_layoutChange_parents.clear();
}
 
void QSortFilterProxyModelPrivate::_q_sourceRowsAboutToBeInserted(
    const QModelIndex &source_parent, int start, int end)
{
    Q_UNUSED(start);
    Q_UNUSED(end);
 
    const bool toplevel = !source_parent.isValid();
    const bool recursive_accepted = filter_recursive && !toplevel && filterAcceptsRowInternal(source_parent.row(), source_parent.parent());
    //Force the creation of a mapping now, even if it's empty.
    //We need it because the proxy can be accessed at the moment it emits rowsAboutToBeInserted in insert_source_items
    if (!filter_recursive || toplevel || recursive_accepted) {
        if (can_create_mapping(source_parent))
            create_mapping(source_parent);
        if (filter_recursive)
            complete_insert = true;
    } else {
        // The row could have been rejected or the parent might be not yet known... let's try to discover it
        QModelIndex top_source_parent = source_parent;
        QModelIndex parent = source_parent.parent();
        QModelIndex grandParent = parent.parent();
 
        while (parent.isValid() && !filterAcceptsRowInternal(parent.row(), grandParent)) {
            top_source_parent = parent;
            parent = grandParent;
            grandParent = parent.parent();
        }
 
        last_top_source = top_source_parent;
    }
}
 
void QSortFilterProxyModelPrivate::_q_sourceRowsInserted(
    const QModelIndex &source_parent, int start, int end)
{
    if (!filter_recursive || complete_insert) {
        if (filter_recursive)
            complete_insert = false;
        source_items_inserted(source_parent, start, end, Qt::Vertical);
        if (update_source_sort_column() && dynamic_sortfilter) //previous call to update_source_sort_column may fail if the model has no column.
            sort();                      // now it should succeed so we need to make sure to sort again
        return;
    }
 
    if (filter_recursive) {
        bool accept = false;
 
        for (int row = start; row <= end; ++row) {
            if (filterAcceptsRowInternal(row, source_parent)) {
                accept = true;
                break;
            }
        }
 
        if (!accept) // the new rows have no descendants that match the filter, filter them out.
            return;
 
        // last_top_source should now become visible
        _q_sourceDataChanged(last_top_source, last_top_source, QList<int>());
    }
}
 
void QSortFilterProxyModelPrivate::_q_sourceRowsAboutToBeRemoved(
    const QModelIndex &source_parent, int start, int end)
{
    itemsBeingRemoved = QRowsRemoval(source_parent, start, end);
    source_items_about_to_be_removed(source_parent, start, end,
                                     Qt::Vertical);
}
 
void QSortFilterProxyModelPrivate::_q_sourceRowsRemoved(
    const QModelIndex &source_parent, int start, int end)
{
    itemsBeingRemoved = QRowsRemoval();
    source_items_removed(source_parent, start, end, Qt::Vertical);
 
    if (filter_recursive) {
        // Find out if removing this visible row means that some ascendant
        // row can now be hidden.
        // We go up until we find a row that should still be visible
        // and then make QSFPM re-evaluate the last one we saw before that, to hide it.
 
        QModelIndex to_hide;
        QModelIndex source_ascendant = source_parent;
 
        while (source_ascendant.isValid()) {
            if (filterAcceptsRowInternal(source_ascendant.row(), source_ascendant.parent()))
                break;
 
            to_hide = source_ascendant;
            source_ascendant = source_ascendant.parent();
        }
 
        if (to_hide.isValid())
            _q_sourceDataChanged(to_hide, to_hide, QList<int>());
    }
}
 
void QSortFilterProxyModelPrivate::_q_sourceRowsAboutToBeMoved(
    const QModelIndex &sourceParent, int /* sourceStart */, int /* sourceEnd */, const QModelIndex &destParent, int /* dest */)
{
    // Because rows which are contiguous in the source model might not be contiguous
    // in the proxy due to sorting, the best thing we can do here is be specific about what
    // parents are having their children changed.
    // Optimize: Emit move signals if the proxy is not sorted. Will need to account for rows
    // being filtered out though.
 
    QList<QPersistentModelIndex> parents;
    parents << sourceParent;
    if (sourceParent != destParent)
        parents << destParent;
    _q_sourceLayoutAboutToBeChanged(parents, QAbstractItemModel::NoLayoutChangeHint);
}
 
void QSortFilterProxyModelPrivate::_q_sourceRowsMoved(
    const QModelIndex &sourceParent, int /* sourceStart */, int /* sourceEnd */, const QModelIndex &destParent, int /* dest */)
{
    QList<QPersistentModelIndex> parents;
    parents << sourceParent;
    if (sourceParent != destParent)
        parents << destParent;
    _q_sourceLayoutChanged(parents, QAbstractItemModel::NoLayoutChangeHint);
}
 
void QSortFilterProxyModelPrivate::_q_sourceColumnsAboutToBeInserted(
    const QModelIndex &source_parent, int start, int end)
{
    Q_UNUSED(start);
    Q_UNUSED(end);
    //Force the creation of a mapping now, even if it's empty.
    //We need it because the proxy can be accessed at the moment it emits columnsAboutToBeInserted in insert_source_items
    if (can_create_mapping(source_parent))
        create_mapping(source_parent);
}
 
void QSortFilterProxyModelPrivate::_q_sourceColumnsInserted(
    const QModelIndex &source_parent, int start, int end)
{
    Q_Q(const QSortFilterProxyModel);
    source_items_inserted(source_parent, start, end, Qt::Horizontal);
 
    if (source_parent.isValid())
        return; //we sort according to the root column only
    if (source_sort_column == -1) {
        //we update the source_sort_column depending on the proxy_sort_column
        if (update_source_sort_column() && dynamic_sortfilter)
            sort();
    } else {
        if (start <= source_sort_column)
            source_sort_column += end - start + 1;
 
        proxy_sort_column = q->mapFromSource(model->index(0,source_sort_column, source_parent)).column();
    }
}
 
void QSortFilterProxyModelPrivate::_q_sourceColumnsAboutToBeRemoved(
    const QModelIndex &source_parent, int start, int end)
{
    source_items_about_to_be_removed(source_parent, start, end,
                                     Qt::Horizontal);
}
 
void QSortFilterProxyModelPrivate::_q_sourceColumnsRemoved(
    const QModelIndex &source_parent, int start, int end)
{
    Q_Q(const QSortFilterProxyModel);
    source_items_removed(source_parent, start, end, Qt::Horizontal);
 
    if (source_parent.isValid())
        return; //we sort according to the root column only
    if (start <= source_sort_column) {
        if (end < source_sort_column)
            source_sort_column -= end - start + 1;
        else
            source_sort_column = -1;
    }
 
    if (source_sort_column >= 0)
        proxy_sort_column = q->mapFromSource(model->index(0,source_sort_column, source_parent)).column();
    else
        proxy_sort_column = -1;
}
 
void QSortFilterProxyModelPrivate::_q_sourceColumnsAboutToBeMoved(
    const QModelIndex &sourceParent, int /* sourceStart */, int /* sourceEnd */, const QModelIndex &destParent, int /* dest */)
{
    QList<QPersistentModelIndex> parents;
    parents << sourceParent;
    if (sourceParent != destParent)
        parents << destParent;
    _q_sourceLayoutAboutToBeChanged(parents, QAbstractItemModel::NoLayoutChangeHint);
}
 
void QSortFilterProxyModelPrivate::_q_sourceColumnsMoved(
    const QModelIndex &sourceParent, int /* sourceStart */, int /* sourceEnd */, const QModelIndex &destParent, int /* dest */)
{
    QList<QPersistentModelIndex> parents;
    parents << sourceParent;
    if (sourceParent != destParent)
        parents << destParent;
    _q_sourceLayoutChanged(parents, QAbstractItemModel::NoLayoutChangeHint);
}
 
QSortFilterProxyModel::QSortFilterProxyModel(QObject *parent)
    : QAbstractProxyModel(*new QSortFilterProxyModelPrivate, parent)
{
    Q_D(QSortFilterProxyModel);
    QObjectPrivate::connect(this, &QAbstractItemModel::modelReset, d,
                            &QSortFilterProxyModelPrivate::_q_clearMapping);
}
 
QSortFilterProxyModel::~QSortFilterProxyModel()
{
    Q_D(QSortFilterProxyModel);
    qDeleteAll(d->source_index_mapping);
    d->source_index_mapping.clear();
}
 
void QSortFilterProxyModel::setSourceModel(QAbstractItemModel *sourceModel)
{
    Q_D(QSortFilterProxyModel);
 
    if (sourceModel == d->model)
        return;
 
    beginResetModel();
 
    if (d->model) {
        for (const QMetaObject::Connection &connection : std::as_const(d->sourceConnections))
            disconnect(connection);
    }
 
    // same as in _q_sourceReset()
    d->invalidatePersistentIndexes();
    d->_q_clearMapping();
 
    QAbstractProxyModel::setSourceModel(sourceModel);
 
    d->sourceConnections = std::array<QMetaObject::Connection, 18>{
        QObjectPrivate::connect(d->model, &QAbstractItemModel::dataChanged, d,
                                &QSortFilterProxyModelPrivate::_q_sourceDataChanged),
 
        QObjectPrivate::connect(d->model, &QAbstractItemModel::headerDataChanged, d,
                                &QSortFilterProxyModelPrivate::_q_sourceHeaderDataChanged),
 
        QObjectPrivate::connect(d->model, &QAbstractItemModel::rowsAboutToBeInserted, d,
                                &QSortFilterProxyModelPrivate::_q_sourceRowsAboutToBeInserted),
 
        QObjectPrivate::connect(d->model, &QAbstractItemModel::rowsInserted, d,
                                &QSortFilterProxyModelPrivate::_q_sourceRowsInserted),
 
        QObjectPrivate::connect(d->model, &QAbstractItemModel::columnsAboutToBeInserted, d,
                                &QSortFilterProxyModelPrivate::_q_sourceColumnsAboutToBeInserted),
 
        QObjectPrivate::connect(d->model, &QAbstractItemModel::columnsInserted, d,
                                &QSortFilterProxyModelPrivate::_q_sourceColumnsInserted),
 
        QObjectPrivate::connect(d->model, &QAbstractItemModel::rowsAboutToBeRemoved, d,
                                &QSortFilterProxyModelPrivate::_q_sourceRowsAboutToBeRemoved),
 
        QObjectPrivate::connect(d->model, &QAbstractItemModel::rowsRemoved, d,
                                &QSortFilterProxyModelPrivate::_q_sourceRowsRemoved),
 
        QObjectPrivate::connect(d->model, &QAbstractItemModel::columnsAboutToBeRemoved, d,
                                &QSortFilterProxyModelPrivate::_q_sourceColumnsAboutToBeRemoved),
 
        QObjectPrivate::connect(d->model, &QAbstractItemModel::columnsRemoved, d,
                                &QSortFilterProxyModelPrivate::_q_sourceColumnsRemoved),
 
        QObjectPrivate::connect(d->model, &QAbstractItemModel::rowsAboutToBeMoved, d,
                                &QSortFilterProxyModelPrivate::_q_sourceRowsAboutToBeMoved),
 
        QObjectPrivate::connect(d->model, &QAbstractItemModel::rowsMoved, d,
                                &QSortFilterProxyModelPrivate::_q_sourceRowsMoved),
 
        QObjectPrivate::connect(d->model, &QAbstractItemModel::columnsAboutToBeMoved, d,
                                &QSortFilterProxyModelPrivate::_q_sourceColumnsAboutToBeMoved),
 
        QObjectPrivate::connect(d->model, &QAbstractItemModel::columnsMoved, d,
                                &QSortFilterProxyModelPrivate::_q_sourceColumnsMoved),
 
        QObjectPrivate::connect(d->model, &QAbstractItemModel::layoutAboutToBeChanged, d,
                                &QSortFilterProxyModelPrivate::_q_sourceLayoutAboutToBeChanged),
 
        QObjectPrivate::connect(d->model, &QAbstractItemModel::layoutChanged, d,
                                &QSortFilterProxyModelPrivate::_q_sourceLayoutChanged),
 
        QObjectPrivate::connect(d->model, &QAbstractItemModel::modelAboutToBeReset, d,
                                &QSortFilterProxyModelPrivate::_q_sourceAboutToBeReset),
 
        QObjectPrivate::connect(d->model, &QAbstractItemModel::modelReset, d,
                                &QSortFilterProxyModelPrivate::_q_sourceReset)
    };
    endResetModel();
    if (d->update_source_sort_column() && d->dynamic_sortfilter)
        d->sort();
}
 
QModelIndex QSortFilterProxyModel::index(int row, int column, const QModelIndex &parent) const
{
    Q_D(const QSortFilterProxyModel);
    if (row < 0 || column < 0)
        return QModelIndex();
 
    QModelIndex source_parent = mapToSource(parent); // parent is already mapped at this point
    IndexMap::const_iterator it = d->create_mapping(source_parent); // but make sure that the children are mapped
    if (it.value()->source_rows.size() <= row || it.value()->source_columns.size() <= column)
        return QModelIndex();
 
    return d->create_index(row, column, it);
}
 
QModelIndex QSortFilterProxyModel::parent(const QModelIndex &child) const
{
    Q_D(const QSortFilterProxyModel);
    if (!d->indexValid(child))
        return QModelIndex();
    IndexMap::const_iterator it = d->index_to_iterator(child);
    Q_ASSERT(it != d->source_index_mapping.constEnd());
    QModelIndex source_parent = it.key();
    QModelIndex proxy_parent = mapFromSource(source_parent);
    return proxy_parent;
}
 
QModelIndex QSortFilterProxyModel::sibling(int row, int column, const QModelIndex &idx) const
{
    Q_D(const QSortFilterProxyModel);
    if (!d->indexValid(idx))
        return QModelIndex();
 
    const IndexMap::const_iterator it = d->index_to_iterator(idx);
    if (it.value()->source_rows.size() <= row || it.value()->source_columns.size() <= column)
        return QModelIndex();
 
    return d->create_index(row, column, it);
}
 
int QSortFilterProxyModel::rowCount(const QModelIndex &parent) const
{
    Q_D(const QSortFilterProxyModel);
    QModelIndex source_parent = mapToSource(parent);
    if (parent.isValid() && !source_parent.isValid())
        return 0;
    IndexMap::const_iterator it = d->create_mapping(source_parent);
    return it.value()->source_rows.size();
}
 
int QSortFilterProxyModel::columnCount(const QModelIndex &parent) const
{
    Q_D(const QSortFilterProxyModel);
    QModelIndex source_parent = mapToSource(parent);
    if (parent.isValid() && !source_parent.isValid())
        return 0;
    IndexMap::const_iterator it = d->create_mapping(source_parent);
    return it.value()->source_columns.size();
}
 
bool QSortFilterProxyModel::hasChildren(const QModelIndex &parent) const
{
    Q_D(const QSortFilterProxyModel);
    QModelIndex source_parent = mapToSource(parent);
    if (parent.isValid() && !source_parent.isValid())
        return false;
    if (!d->model->hasChildren(source_parent))
        return false;
 
    if (d->model->canFetchMore(source_parent))
        return true; //we assume we might have children that can be fetched
 
    QSortFilterProxyModelPrivate::Mapping *m = d->create_mapping(source_parent).value();
    return m->source_rows.size() != 0 && m->source_columns.size() != 0;
}
 
QVariant QSortFilterProxyModel::data(const QModelIndex &index, int role) const
{
    Q_D(const QSortFilterProxyModel);
    QModelIndex source_index = mapToSource(index);
    if (index.isValid() && !source_index.isValid())
        return QVariant();
    return d->model->data(source_index, role);
}
 
bool QSortFilterProxyModel::setData(const QModelIndex &index, const QVariant &value, int role)
{
    Q_D(QSortFilterProxyModel);
    QModelIndex source_index = mapToSource(index);
    if (index.isValid() && !source_index.isValid())
        return false;
    return d->model->setData(source_index, value, role);
}
 
QVariant QSortFilterProxyModel::headerData(int section, Qt::Orientation orientation, int role) const
{
    Q_D(const QSortFilterProxyModel);
    IndexMap::const_iterator it = d->create_mapping(QModelIndex());
    if (it.value()->source_rows.size() * it.value()->source_columns.size() > 0)
        return QAbstractProxyModel::headerData(section, orientation, role);
    int source_section;
    if (orientation == Qt::Vertical) {
        if (section < 0 || section >= it.value()->source_rows.size())
            return QVariant();
        source_section = it.value()->source_rows.at(section);
    } else {
        if (section < 0 || section >= it.value()->source_columns.size())
            return QVariant();
        source_section = it.value()->source_columns.at(section);
    }
    return d->model->headerData(source_section, orientation, role);
}
 
bool QSortFilterProxyModel::setHeaderData(int section, Qt::Orientation orientation,
                                          const QVariant &value, int role)
{
    Q_D(QSortFilterProxyModel);
    IndexMap::const_iterator it = d->create_mapping(QModelIndex());
    if (it.value()->source_rows.size() * it.value()->source_columns.size() > 0)
        return QAbstractProxyModel::setHeaderData(section, orientation, value, role);
    int source_section;
    if (orientation == Qt::Vertical) {
        if (section < 0 || section >= it.value()->source_rows.size())
            return false;
        source_section = it.value()->source_rows.at(section);
    } else {
        if (section < 0 || section >= it.value()->source_columns.size())
            return false;
        source_section = it.value()->source_columns.at(section);
    }
    return d->model->setHeaderData(source_section, orientation, value, role);
}
 
QMimeData *QSortFilterProxyModel::mimeData(const QModelIndexList &indexes) const
{
    Q_D(const QSortFilterProxyModel);
    QModelIndexList source_indexes;
    source_indexes.reserve(indexes.size());
    for (const QModelIndex &idx : indexes)
        source_indexes << mapToSource(idx);
    return d->model->mimeData(source_indexes);
}
 
QStringList QSortFilterProxyModel::mimeTypes() const
{
    Q_D(const QSortFilterProxyModel);
    return d->model->mimeTypes();
}
 
Qt::DropActions QSortFilterProxyModel::supportedDropActions() const
{
    Q_D(const QSortFilterProxyModel);
    return d->model->supportedDropActions();
}
 
// Qt6: remove unnecessary reimplementation
bool QSortFilterProxyModel::dropMimeData(const QMimeData *data, Qt::DropAction action,
                                         int row, int column, const QModelIndex &parent)
{
    return QAbstractProxyModel::dropMimeData(data, action, row, column, parent);
}
 
bool QSortFilterProxyModel::insertRows(int row, int count, const QModelIndex &parent)
{
    Q_D(QSortFilterProxyModel);
    if (row < 0 || count <= 0)
        return false;
    QModelIndex source_parent = mapToSource(parent);
    if (parent.isValid() && !source_parent.isValid())
        return false;
    QSortFilterProxyModelPrivate::Mapping *m = d->create_mapping(source_parent).value();
    if (row > m->source_rows.size())
        return false;
    int source_row = (row >= m->source_rows.size()
                      ? m->proxy_rows.size()
                      : m->source_rows.at(row));
    return d->model->insertRows(source_row, count, source_parent);
}
 
bool QSortFilterProxyModel::insertColumns(int column, int count, const QModelIndex &parent)
{
    Q_D(QSortFilterProxyModel);
    if (column < 0|| count <= 0)
        return false;
    QModelIndex source_parent = mapToSource(parent);
    if (parent.isValid() && !source_parent.isValid())
        return false;
    QSortFilterProxyModelPrivate::Mapping *m = d->create_mapping(source_parent).value();
    if (column > m->source_columns.size())
        return false;
    int source_column = (column >= m->source_columns.size()
                         ? m->proxy_columns.size()
                         : m->source_columns.at(column));
    return d->model->insertColumns(source_column, count, source_parent);
}
 
bool QSortFilterProxyModel::removeRows(int row, int count, const QModelIndex &parent)
{
    Q_D(QSortFilterProxyModel);
    if (row < 0 || count <= 0)
        return false;
    QModelIndex source_parent = mapToSource(parent);
    if (parent.isValid() && !source_parent.isValid())
        return false;
    QSortFilterProxyModelPrivate::Mapping *m = d->create_mapping(source_parent).value();
    if (row + count > m->source_rows.size())
        return false;
    if ((count == 1)
        || ((d->source_sort_column < 0) && (m->proxy_rows.size() == m->source_rows.size()))) {
        int source_row = m->source_rows.at(row);
        return d->model->removeRows(source_row, count, source_parent);
    }
    // remove corresponding source intervals
    // ### if this proves to be slow, we can switch to single-row removal
    QList<int> rows;
    rows.reserve(count);
    for (int i = row; i < row + count; ++i)
        rows.append(m->source_rows.at(i));
    std::sort(rows.begin(), rows.end());
 
    int pos = rows.size() - 1;
    bool ok = true;
    while (pos >= 0) {
        const int source_end = rows.at(pos--);
        int source_start = source_end;
        while ((pos >= 0) && (rows.at(pos) == (source_start - 1))) {
            --source_start;
            --pos;
        }
        ok = ok && d->model->removeRows(source_start, source_end - source_start + 1,
                                        source_parent);
    }
    return ok;
}
 
bool QSortFilterProxyModel::removeColumns(int column, int count, const QModelIndex &parent)
{
    Q_D(QSortFilterProxyModel);
    if (column < 0 || count <= 0)
        return false;
    QModelIndex source_parent = mapToSource(parent);
    if (parent.isValid() && !source_parent.isValid())
        return false;
    QSortFilterProxyModelPrivate::Mapping *m = d->create_mapping(source_parent).value();
    if (column + count > m->source_columns.size())
        return false;
    if ((count == 1) || (m->proxy_columns.size() == m->source_columns.size())) {
        int source_column = m->source_columns.at(column);
        return d->model->removeColumns(source_column, count, source_parent);
    }
    // remove corresponding source intervals
    QList<int> columns;
    columns.reserve(count);
    for (int i = column; i < column + count; ++i)
        columns.append(m->source_columns.at(i));
 
    int pos = columns.size() - 1;
    bool ok = true;
    while (pos >= 0) {
        const int source_end = columns.at(pos--);
        int source_start = source_end;
        while ((pos >= 0) && (columns.at(pos) == (source_start - 1))) {
            --source_start;
            --pos;
        }
        ok = ok && d->model->removeColumns(source_start, source_end - source_start + 1,
                                           source_parent);
    }
    return ok;
}
 
void QSortFilterProxyModel::fetchMore(const QModelIndex &parent)
{
    QAbstractProxyModel::fetchMore(parent);
}
 
bool QSortFilterProxyModel::canFetchMore(const QModelIndex &parent) const
{
    return QAbstractProxyModel::canFetchMore(parent);
}
 
Qt::ItemFlags QSortFilterProxyModel::flags(const QModelIndex &index) const
{
    return QAbstractProxyModel::flags(index);
}
 
QModelIndex QSortFilterProxyModel::buddy(const QModelIndex &index) const
{
    Q_D(const QSortFilterProxyModel);
    if (!d->indexValid(index))
        return QModelIndex();
    QModelIndex source_index = mapToSource(index);
    QModelIndex source_buddy = d->model->buddy(source_index);
    if (source_index == source_buddy)
        return index;
    return mapFromSource(source_buddy);
}
 
QModelIndexList QSortFilterProxyModel::match(const QModelIndex &start, int role,
                                             const QVariant &value, int hits,
                                             Qt::MatchFlags flags) const
{
    return QAbstractProxyModel::match(start, role, value, hits, flags);
}
 
QSize QSortFilterProxyModel::span(const QModelIndex &index) const
{
    Q_D(const QSortFilterProxyModel);
    QModelIndex source_index = mapToSource(index);
    if (index.isValid() && !source_index.isValid())
        return QSize();
    return d->model->span(source_index);
}
 
void QSortFilterProxyModel::sort(int column, Qt::SortOrder order)
{
    Q_D(QSortFilterProxyModel);
    if (d->dynamic_sortfilter && d->proxy_sort_column == column && d->sort_order == order)
        return;
    d->sort_order = order;
    d->proxy_sort_column = column;
    d->update_source_sort_column();
    d->sort();
}
 
int QSortFilterProxyModel::sortColumn() const
{
    Q_D(const QSortFilterProxyModel);
    return d->proxy_sort_column;
}
 
Qt::SortOrder QSortFilterProxyModel::sortOrder() const
{
    Q_D(const QSortFilterProxyModel);
    return d->sort_order;
}
 
QRegularExpression QSortFilterProxyModel::filterRegularExpression() const
{
    Q_D(const QSortFilterProxyModel);
    return d->filter_regularexpression;
}
 
QBindable<QRegularExpression> QSortFilterProxyModel::bindableFilterRegularExpression()
{
    Q_D(QSortFilterProxyModel);
    return QBindable<QRegularExpression>(&d->filter_regularexpression);
}
 
void QSortFilterProxyModel::setFilterRegularExpression(const QRegularExpression &regularExpression)
{
    Q_D(QSortFilterProxyModel);
    const QScopedPropertyUpdateGroup guard;
    const bool regExpChanged =
            regularExpression != d->filter_regularexpression.valueBypassingBindings();
    d->filter_regularexpression.removeBindingUnlessInWrapper();
    d->filter_casesensitive.removeBindingUnlessInWrapper();
    const Qt::CaseSensitivity cs = d->filter_casesensitive.valueBypassingBindings();
    d->filter_about_to_be_changed();
    const Qt::CaseSensitivity updatedCs =
            regularExpression.patternOptions() & QRegularExpression::CaseInsensitiveOption
            ? Qt::CaseInsensitive : Qt::CaseSensitive;
    d->filter_regularexpression.setValueBypassingBindings(regularExpression);
    if (cs != updatedCs)
        d->filter_casesensitive.setValueBypassingBindings(updatedCs);
    d->filter_changed(QSortFilterProxyModelPrivate::Direction::Rows);
    // Do not change the evaluation logic, but notify only if the regular
    // expression has actually changed.
    if (regExpChanged)
        d->filter_regularexpression.notify();
    if (cs != updatedCs)
        d->filter_casesensitive.notify();
}
 
int QSortFilterProxyModel::filterKeyColumn() const
{
    Q_D(const QSortFilterProxyModel);
    return d->filter_column;
}
 
void QSortFilterProxyModel::setFilterKeyColumn(int column)
{
    // While introducing new bindable properties, we still update the value
    // unconditionally (even if it didn't really change), and call the
    // filter_about_to_be_changed()/filter_changed() methods, so that we do
    // not break any code. However we do notify the observing bindings only
    // if the column has actually changed
    Q_D(QSortFilterProxyModel);
    d->filter_column.removeBindingUnlessInWrapper();
    d->filter_about_to_be_changed();
    const auto oldColumn = d->filter_column.valueBypassingBindings();
    d->filter_column.setValueBypassingBindings(column);
    d->filter_changed(QSortFilterProxyModelPrivate::Direction::Rows);
    if (oldColumn != column)
        d->filter_column.notify();
}
 
QBindable<int> QSortFilterProxyModel::bindableFilterKeyColumn()
{
    Q_D(QSortFilterProxyModel);
    return QBindable<int>(&d->filter_column);
}
 
Qt::CaseSensitivity QSortFilterProxyModel::filterCaseSensitivity() const
{
    Q_D(const QSortFilterProxyModel);
    return d->filter_casesensitive;
}
 
void QSortFilterProxyModel::setFilterCaseSensitivity(Qt::CaseSensitivity cs)
{
    Q_D(QSortFilterProxyModel);
    d->filter_casesensitive.removeBindingUnlessInWrapper();
    d->filter_regularexpression.removeBindingUnlessInWrapper();
    if (cs == d->filter_casesensitive)
        return;
 
    const QScopedPropertyUpdateGroup guard;
    QRegularExpression::PatternOptions options =
            d->filter_regularexpression.value().patternOptions();
    options.setFlag(QRegularExpression::CaseInsensitiveOption, cs == Qt::CaseInsensitive);
    d->filter_casesensitive.setValueBypassingBindings(cs);
 
    d->filter_about_to_be_changed();
    QRegularExpression re = d->filter_regularexpression;
    re.setPatternOptions(options);
    d->filter_regularexpression.setValueBypassingBindings(re);
    d->filter_changed(QSortFilterProxyModelPrivate::Direction::Rows);
    d->filter_regularexpression.notify();
    d->filter_casesensitive.notify();
}
 
QBindable<Qt::CaseSensitivity> QSortFilterProxyModel::bindableFilterCaseSensitivity()
{
    Q_D(QSortFilterProxyModel);
    return QBindable<Qt::CaseSensitivity>(&d->filter_casesensitive);
}
 
Qt::CaseSensitivity QSortFilterProxyModel::sortCaseSensitivity() const
{
    Q_D(const QSortFilterProxyModel);
    return d->sort_casesensitivity;
}
 
void QSortFilterProxyModel::setSortCaseSensitivity(Qt::CaseSensitivity cs)
{
    Q_D(QSortFilterProxyModel);
    d->sort_casesensitivity.removeBindingUnlessInWrapper();
    if (d->sort_casesensitivity == cs)
        return;
 
    d->sort_casesensitivity.setValueBypassingBindings(cs);
    d->sort();
    d->sort_casesensitivity.notify(); // also emits a signal
}
 
QBindable<Qt::CaseSensitivity> QSortFilterProxyModel::bindableSortCaseSensitivity()
{
    Q_D(QSortFilterProxyModel);
    return QBindable<Qt::CaseSensitivity>(&d->sort_casesensitivity);
}
 
bool QSortFilterProxyModel::isSortLocaleAware() const
{
    Q_D(const QSortFilterProxyModel);
    return d->sort_localeaware;
}
 
void QSortFilterProxyModel::setSortLocaleAware(bool on)
{
    Q_D(QSortFilterProxyModel);
    d->sort_localeaware.removeBindingUnlessInWrapper();
    if (d->sort_localeaware == on)
        return;
 
    d->sort_localeaware.setValueBypassingBindings(on);
    d->sort();
    d->sort_localeaware.notify(); // also emits a signal
}
 
QBindable<bool> QSortFilterProxyModel::bindableIsSortLocaleAware()
{
    Q_D(QSortFilterProxyModel);
    return QBindable<bool>(&d->sort_localeaware);
}
 
void QSortFilterProxyModel::setFilterRegularExpression(const QString &pattern)
{
    Q_D(QSortFilterProxyModel);
    d->filter_regularexpression.removeBindingUnlessInWrapper();
    d->filter_about_to_be_changed();
    d->set_filter_pattern(pattern);
    d->filter_changed(QSortFilterProxyModelPrivate::Direction::Rows);
    d->filter_regularexpression.notify();
}
 
void QSortFilterProxyModel::setFilterWildcard(const QString &pattern)
{
    Q_D(QSortFilterProxyModel);
    d->filter_regularexpression.removeBindingUnlessInWrapper();
    d->filter_about_to_be_changed();
    d->set_filter_pattern(QRegularExpression::wildcardToRegularExpression(
            pattern, QRegularExpression::UnanchoredWildcardConversion));
    d->filter_changed(QSortFilterProxyModelPrivate::Direction::Rows);
    d->filter_regularexpression.notify();
}
 
void QSortFilterProxyModel::setFilterFixedString(const QString &pattern)
{
    Q_D(QSortFilterProxyModel);
    d->filter_regularexpression.removeBindingUnlessInWrapper();
    d->filter_about_to_be_changed();
    d->set_filter_pattern(QRegularExpression::escape(pattern));
    d->filter_changed(QSortFilterProxyModelPrivate::Direction::Rows);
    d->filter_regularexpression.notify();
}
 
bool QSortFilterProxyModel::dynamicSortFilter() const
{
    Q_D(const QSortFilterProxyModel);
    return d->dynamic_sortfilter;
}
 
void QSortFilterProxyModel::setDynamicSortFilter(bool enable)
{
    // While introducing new bindable properties, we still update the value
    // unconditionally (even if it didn't really change), and call the
    // sort() method, so that we do not break any code.
    // However we do notify the observing bindings only if the value has
    // actually changed.
    Q_D(QSortFilterProxyModel);
    d->dynamic_sortfilter.removeBindingUnlessInWrapper();
    const bool valueChanged = d->dynamic_sortfilter.value() != enable;
    d->dynamic_sortfilter.setValueBypassingBindings(enable);
    if (enable)
        d->sort();
    if (valueChanged)
        d->dynamic_sortfilter.notify();
}
 
QBindable<bool> QSortFilterProxyModel::bindableDynamicSortFilter()
{
    Q_D(QSortFilterProxyModel);
    return QBindable<bool>(&d->dynamic_sortfilter);
}
 
int QSortFilterProxyModel::sortRole() const
{
    Q_D(const QSortFilterProxyModel);
    return d->sort_role;
}
 
void QSortFilterProxyModel::setSortRole(int role)
{
    Q_D(QSortFilterProxyModel);
    d->sort_role.removeBindingUnlessInWrapper();
    if (d->sort_role.valueBypassingBindings() == role)
        return;
    d->sort_role.setValueBypassingBindings(role);
    d->sort();
    d->sort_role.notify(); // also emits a signal
}
 
QBindable<int> QSortFilterProxyModel::bindableSortRole()
{
    Q_D(QSortFilterProxyModel);
    return QBindable<int>(&d->sort_role);
}
 
int QSortFilterProxyModel::filterRole() const
{
    Q_D(const QSortFilterProxyModel);
    return d->filter_role;
}
 
void QSortFilterProxyModel::setFilterRole(int role)
{
    Q_D(QSortFilterProxyModel);
    d->filter_role.removeBindingUnlessInWrapper();
    if (d->filter_role.valueBypassingBindings() == role)
        return;
    d->filter_about_to_be_changed();
    d->filter_role.setValueBypassingBindings(role);
    d->filter_changed(QSortFilterProxyModelPrivate::Direction::Rows);
    d->filter_role.notify(); // also emits a signal
}
 
QBindable<int> QSortFilterProxyModel::bindableFilterRole()
{
    Q_D(QSortFilterProxyModel);
    return QBindable<int>(&d->filter_role);
}
 
bool QSortFilterProxyModel::isRecursiveFilteringEnabled() const
{
    Q_D(const QSortFilterProxyModel);
    return d->filter_recursive;
}
 
void QSortFilterProxyModel::setRecursiveFilteringEnabled(bool recursive)
{
    Q_D(QSortFilterProxyModel);
    d->filter_recursive.removeBindingUnlessInWrapper();
    if (d->filter_recursive == recursive)
        return;
    d->filter_about_to_be_changed();
    d->filter_recursive.setValueBypassingBindings(recursive);
    d->filter_changed(QSortFilterProxyModelPrivate::Direction::Rows);
    d->filter_recursive.notify(); // also emits a signal
}
 
QBindable<bool> QSortFilterProxyModel::bindableRecursiveFilteringEnabled()
{
    Q_D(QSortFilterProxyModel);
    return QBindable<bool>(&d->filter_recursive);
}
 
bool QSortFilterProxyModel::autoAcceptChildRows() const
{
    Q_D(const QSortFilterProxyModel);
    return d->accept_children;
}
 
void QSortFilterProxyModel::setAutoAcceptChildRows(bool accept)
{
    Q_D(QSortFilterProxyModel);
    d->accept_children.removeBindingUnlessInWrapper();
    if (d->accept_children == accept)
        return;
 
    d->filter_about_to_be_changed();
    d->accept_children.setValueBypassingBindings(accept);
    d->filter_changed(QSortFilterProxyModelPrivate::Direction::Rows);
    d->accept_children.notify(); // also emits a signal
}
 
QBindable<bool> QSortFilterProxyModel::bindableAutoAcceptChildRows()
{
    Q_D(QSortFilterProxyModel);
    return QBindable<bool>(&d->accept_children);
}
 
void QSortFilterProxyModel::invalidate()
{
    Q_D(QSortFilterProxyModel);
    emit layoutAboutToBeChanged();
    d->_q_clearMapping();
    emit layoutChanged();
}
 
void QSortFilterProxyModel::invalidateFilter()
{
    Q_D(QSortFilterProxyModel);
    d->filter_changed(QSortFilterProxyModelPrivate::Direction::All);
}
 
void QSortFilterProxyModel::invalidateColumnsFilter()
{
    Q_D(QSortFilterProxyModel);
    d->filter_changed(QSortFilterProxyModelPrivate::Direction::Columns);
}
 
void QSortFilterProxyModel::invalidateRowsFilter()
{
    Q_D(QSortFilterProxyModel);
    d->filter_changed(QSortFilterProxyModelPrivate::Direction::Rows);
}
 
bool QSortFilterProxyModel::lessThan(const QModelIndex &source_left, const QModelIndex &source_right) const
{
    Q_D(const QSortFilterProxyModel);
    QVariant l = (source_left.model() ? source_left.model()->data(source_left, d->sort_role) : QVariant());
    QVariant r = (source_right.model() ? source_right.model()->data(source_right, d->sort_role) : QVariant());
    return QAbstractItemModelPrivate::isVariantLessThan(l, r, d->sort_casesensitivity, d->sort_localeaware);
}
 
bool QSortFilterProxyModel::filterAcceptsRow(int source_row, const QModelIndex &source_parent) const
{
    Q_D(const QSortFilterProxyModel);
 
    if (d->filter_regularexpression.value().pattern().isEmpty())
        return true;
 
    int column_count = d->model->columnCount(source_parent);
    if (d->filter_column == -1) {
        for (int column = 0; column < column_count; ++column) {
            QModelIndex source_index = d->model->index(source_row, column, source_parent);
            QString key = d->model->data(source_index, d->filter_role).toString();
            if (key.contains(d->filter_regularexpression.value()))
                return true;
        }
        return false;
    }
 
    if (d->filter_column >= column_count) // the column may not exist
        return true;
    QModelIndex source_index = d->model->index(source_row, d->filter_column, source_parent);
    QString key = d->model->data(source_index, d->filter_role).toString();
    return key.contains(d->filter_regularexpression.value());
}
 
bool QSortFilterProxyModel::filterAcceptsColumn(int source_column, const QModelIndex &source_parent) const
{
    Q_UNUSED(source_column);
    Q_UNUSED(source_parent);
    return true;
}
 
QModelIndex QSortFilterProxyModel::mapToSource(const QModelIndex &proxyIndex) const
{
    Q_D(const QSortFilterProxyModel);
    return d->proxy_to_source(proxyIndex);
}
 
QModelIndex QSortFilterProxyModel::mapFromSource(const QModelIndex &sourceIndex) const
{
    Q_D(const QSortFilterProxyModel);
    return d->source_to_proxy(sourceIndex);
}
 
QItemSelection QSortFilterProxyModel::mapSelectionToSource(const QItemSelection &proxySelection) const
{
    return QAbstractProxyModel::mapSelectionToSource(proxySelection);
}
 
QItemSelection QSortFilterProxyModel::mapSelectionFromSource(const QItemSelection &sourceSelection) const
{
    return QAbstractProxyModel::mapSelectionFromSource(sourceSelection);
}
 
QT_END_NAMESPACE
 
#include "moc_qsortfilterproxymodel.cpp"