New proxy model: QTransposeProxyModel

Implemented a new proxy model to transpose the source model.
Rows will become columns and vice-versa.
Both flat and tree models supported.

[ChangeLog][QtCore] New class QTransposeProxyModel to
swap rows and columns of the source model.

Change-Id: I902963c6b81aa0f63b5ad2bddca538f28b565084
Reviewed-by: David Faure <david.faure@kdab.com>

9 files changed, 1542 insertions, 0 deletions

diff --git a/src/corelib/configure.json b/src/corelib/configure.json
index f09ef6c1dd..f18e79f1aa 100644
--- a/src/corelib/configure.json
+++ b/src/corelib/configure.json
@@ -793,6 +793,13 @@
             "condition": "features.proxymodel",
             "output": [ "publicFeature", "feature" ]
         },
+        "transposeproxymodel": {
+            "label": "QTransposeProxyModel",
+            "purpose": "Provides a proxy to swap rows and columns of a model.",
+            "section": "ItemViews",
+            "condition": "features.proxymodel",
+            "output": [ "publicFeature", "feature" ]
+        },
         "concatenatetablesproxymodel": {
             "label": "QConcatenateTablesProxyModel",
             "purpose": "Supports concatenating source models.",
diff --git a/src/corelib/itemmodels/itemmodels.pri b/src/corelib/itemmodels/itemmodels.pri
index 5a977c6623..ebeac6e211 100644
--- a/src/corelib/itemmodels/itemmodels.pri
+++ b/src/corelib/itemmodels/itemmodels.pri
@@ -43,6 +43,15 @@ qtConfig(proxymodel) {
         SOURCES += \
             itemmodels/qsortfilterproxymodel.cpp
     }
+
+    qtConfig(transposeproxymodel) {
+        HEADERS += \
+            itemmodels/qtransposeproxymodel.h \
+            itemmodels/qtransposeproxymodel_p.h
+
+        SOURCES += \
+            itemmodels/qtransposeproxymodel.cpp
+    }
 }
 
 qtConfig(stringlistmodel) {
diff --git a/src/corelib/itemmodels/qabstractitemmodel.h b/src/corelib/itemmodels/qabstractitemmodel.h
index bec71b0606..0aa75d6ff7 100644
--- a/src/corelib/itemmodels/qabstractitemmodel.h
+++ b/src/corelib/itemmodels/qabstractitemmodel.h
@@ -163,6 +163,7 @@ typedef QList<QModelIndex> QModelIndexList;
 
 class QMimeData;
 class QAbstractItemModelPrivate;
+class QTransposeProxyModelPrivate;
 template <class Key, class T> class QMap;
 
 
@@ -173,6 +174,7 @@ class Q_CORE_EXPORT QAbstractItemModel : public QObject
     friend class QPersistentModelIndexData;
     friend class QAbstractItemViewPrivate;
     friend class QIdentityProxyModel;
+    friend class QTransposeProxyModelPrivate;
 public:
 
     explicit QAbstractItemModel(QObject *parent = nullptr);
diff --git a/src/corelib/itemmodels/qtransposeproxymodel.cpp b/src/corelib/itemmodels/qtransposeproxymodel.cpp
new file mode 100644
index 0000000000..dd84b97118
--- /dev/null
+++ b/src/corelib/itemmodels/qtransposeproxymodel.cpp
@@ -0,0 +1,446 @@
+/****************************************************************************
+**
+** Copyright (C) 2018 Luca Beldi <v.ronin@yahoo.it>
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the QtCore module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or (at your option) the GNU General
+** Public license version 3 or any later version approved by the KDE Free
+** Qt Foundation. The licenses are as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-2.0.html and
+** https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include "qtransposeproxymodel.h"
+#include <private/qtransposeproxymodel_p.h>
+#include <QtCore/qvector.h>
+#include <QtCore/qmetaobject.h>
+#include <QtCore/qsize.h>
+
+QT_BEGIN_NAMESPACE
+
+QModelIndex QTransposeProxyModelPrivate::uncheckedMapToSource(const QModelIndex &proxyIndex) const
+{
+    if (!model || !proxyIndex.isValid())
+        return QModelIndex();
+    if (proxyIndex.internalPointer())
+        return model->createIndex(proxyIndex.column(), proxyIndex.row(), proxyIndex.internalPointer());
+    return model->index(proxyIndex.column(), proxyIndex.row());
+}
+
+QModelIndex QTransposeProxyModelPrivate::uncheckedMapFromSource(const QModelIndex &sourceIndex) const
+{
+    if (!model || !sourceIndex.isValid())
+        return QModelIndex();
+    Q_Q(const QTransposeProxyModel);
+    return q->createIndex(sourceIndex.column(), sourceIndex.row(), sourceIndex.internalPointer());
+}
+
+void QTransposeProxyModelPrivate::onLayoutChanged(const QList<QPersistentModelIndex> &parents, QAbstractItemModel::LayoutChangeHint hint)
+{
+    Q_Q(QTransposeProxyModel);
+    QModelIndexList toList;
+    toList.reserve(layoutChangePersistentIndexes.size());
+    for (const QPersistentModelIndex &persistIdx : qAsConst(layoutChangePersistentIndexes))
+        toList << q->mapFromSource(persistIdx);
+    q->changePersistentIndexList(layoutChangeProxyIndexes, toList);
+    layoutChangeProxyIndexes.clear();
+    layoutChangePersistentIndexes.clear();
+    QList<QPersistentModelIndex> proxyParents;
+    proxyParents.reserve(parents.size());
+    for (const QPersistentModelIndex &srcParent : parents)
+        proxyParents << q->mapFromSource(srcParent);
+    QAbstractItemModel::LayoutChangeHint proxyHint = QAbstractItemModel::NoLayoutChangeHint;
+    if (hint == QAbstractItemModel::VerticalSortHint)
+        proxyHint = QAbstractItemModel::HorizontalSortHint;
+    else if (hint == QAbstractItemModel::HorizontalSortHint)
+        proxyHint = QAbstractItemModel::VerticalSortHint;
+    q->layoutChanged(proxyParents, proxyHint);
+}
+
+void QTransposeProxyModelPrivate::onLayoutAboutToBeChanged(const QList<QPersistentModelIndex> &parents, QAbstractItemModel::LayoutChangeHint hint)
+{
+    Q_Q(QTransposeProxyModel);
+    const QModelIndexList proxyPersistentIndexes = q->persistentIndexList();
+    layoutChangeProxyIndexes.clear();
+    layoutChangePersistentIndexes.clear();
+    layoutChangeProxyIndexes.reserve(proxyPersistentIndexes.size());
+    layoutChangePersistentIndexes.reserve(proxyPersistentIndexes.size());
+    for (const QPersistentModelIndex &proxyPersistentIndex : proxyPersistentIndexes) {
+        layoutChangeProxyIndexes << proxyPersistentIndex;
+        Q_ASSERT(proxyPersistentIndex.isValid());
+        const QPersistentModelIndex srcPersistentIndex = q->mapToSource(proxyPersistentIndex);
+        Q_ASSERT(srcPersistentIndex.isValid());
+        layoutChangePersistentIndexes << srcPersistentIndex;
+    }
+    QList<QPersistentModelIndex> proxyParents;
+    proxyParents.reserve(parents.size());
+    for (auto& srcParent : parents)
+        proxyParents << q->mapFromSource(srcParent);
+    QAbstractItemModel::LayoutChangeHint proxyHint = QAbstractItemModel::NoLayoutChangeHint;
+    if (hint == QAbstractItemModel::VerticalSortHint)
+        proxyHint = QAbstractItemModel::HorizontalSortHint;
+    else if (hint == QAbstractItemModel::HorizontalSortHint)
+        proxyHint = QAbstractItemModel::VerticalSortHint;
+    q->layoutAboutToBeChanged(proxyParents, proxyHint);
+}
+
+void QTransposeProxyModelPrivate::onDataChanged(const QModelIndex& topLeft, const QModelIndex& bottomRight, const QVector<int>& roles)
+{
+    Q_Q(QTransposeProxyModel);
+    q->dataChanged(q->mapFromSource(topLeft), q->mapFromSource(bottomRight), roles);
+}
+
+void QTransposeProxyModelPrivate::onHeaderDataChanged(Qt::Orientation orientation, int first, int last)
+{
+    Q_Q(QTransposeProxyModel);
+    q->headerDataChanged(orientation == Qt::Horizontal ? Qt::Vertical : Qt::Horizontal, first, last);
+}
+
+void QTransposeProxyModelPrivate::onColumnsAboutToBeInserted(const QModelIndex &parent, int first, int last)
+{
+    Q_Q(QTransposeProxyModel);
+    q->beginInsertRows(q->mapFromSource(parent), first, last);
+}
+
+void QTransposeProxyModelPrivate::onColumnsAboutToBeRemoved(const QModelIndex &parent, int first, int last)
+{
+    Q_Q(QTransposeProxyModel);
+    q->beginRemoveRows(q->mapFromSource(parent), first, last);
+}
+
+void QTransposeProxyModelPrivate::onColumnsAboutToBeMoved(const QModelIndex &sourceParent, int sourceStart, int sourceEnd, const QModelIndex &destinationParent, int destinationColumn)
+{
+    Q_Q(QTransposeProxyModel);
+    q->beginMoveRows(q->mapFromSource(sourceParent), sourceStart, sourceEnd, q->mapFromSource(destinationParent), destinationColumn);
+}
+
+void QTransposeProxyModelPrivate::onRowsAboutToBeInserted(const QModelIndex &parent, int first, int last)
+{
+    Q_Q(QTransposeProxyModel);
+    q->beginInsertColumns(q->mapFromSource(parent), first, last);
+}
+
+void QTransposeProxyModelPrivate::onRowsAboutToBeRemoved(const QModelIndex &parent, int first, int last)
+{
+    Q_Q(QTransposeProxyModel);
+    q->beginRemoveColumns(q->mapFromSource(parent), first, last);
+}
+
+void QTransposeProxyModelPrivate::onRowsAboutToBeMoved(const QModelIndex &sourceParent, int sourceStart, int sourceEnd, const QModelIndex &destinationParent, int destinationRow)
+{
+    Q_Q(QTransposeProxyModel);
+    q->beginMoveColumns(q->mapFromSource(sourceParent), sourceStart, sourceEnd, q->mapFromSource(destinationParent), destinationRow);
+}
+
+/*!
+    \since 5.13
+    \class QTransposeProxyModel
+    \brief This proxy transposes the source model
+    \details This model will make the rows of the source model become columns of the proxy model and vice-versa.
+
+    If the model is a tree, the parents will be transposed as well. For example, if an index in the source model had parent `index(2,0)`, it will have parent `index(0,2)` in the proxy.
+*/
+
+/*!
+    Constructs a new proxy model with the given \a parent.
+*/
+QTransposeProxyModel::QTransposeProxyModel(QObject* parent)
+    : QAbstractProxyModel(*new QTransposeProxyModelPrivate, parent)
+{}
+
+/*!
+    Destructs the proxy model.
+*/
+QTransposeProxyModel::~QTransposeProxyModel() = default;
+
+/*!
+    \internal
+*/
+QTransposeProxyModel::QTransposeProxyModel(QTransposeProxyModelPrivate &dd, QObject *parent)
+    : QAbstractProxyModel(dd, parent)
+{}
+
+/*!
+    \reimp
+*/
+void QTransposeProxyModel::setSourceModel(QAbstractItemModel* newSourceModel)
+{
+    Q_D(QTransposeProxyModel);
+    if (newSourceModel == d->model)
+        return;
+    beginResetModel();
+    if (d->model) {
+        for (const QMetaObject::Connection& discIter : qAsConst(d->sourceConnections))
+            disconnect(discIter);
+    }
+    d->sourceConnections.clear();
+    QAbstractProxyModel::setSourceModel(newSourceModel);
+    if (d->model) {
+        using namespace std::placeholders;
+        d->sourceConnections = QVector<QMetaObject::Connection>{
+            connect(d->model, &QAbstractItemModel::modelAboutToBeReset, this, &QTransposeProxyModel::beginResetModel),
+            connect(d->model, &QAbstractItemModel::modelReset, this, &QTransposeProxyModel::endResetModel),
+            connect(d->model, &QAbstractItemModel::dataChanged, this, std::bind(&QTransposeProxyModelPrivate::onDataChanged, d, _1, _2, _3)),
+            connect(d->model, &QAbstractItemModel::headerDataChanged, this, std::bind(&QTransposeProxyModelPrivate::onHeaderDataChanged, d, _1, _2, _3)),
+            connect(d->model, &QAbstractItemModel::columnsAboutToBeInserted, this, std::bind(&QTransposeProxyModelPrivate::onColumnsAboutToBeInserted, d, _1, _2, _3)),
+            connect(d->model, &QAbstractItemModel::columnsAboutToBeMoved, this, std::bind(&QTransposeProxyModelPrivate::onColumnsAboutToBeMoved, d, _1, _2, _3, _4, _5)),
+            connect(d->model, &QAbstractItemModel::columnsAboutToBeRemoved, this, std::bind(&QTransposeProxyModelPrivate::onColumnsAboutToBeRemoved, d, _1, _2, _3)),
+            connect(d->model, &QAbstractItemModel::columnsInserted, this, &QTransposeProxyModel::endInsertRows),
+            connect(d->model, &QAbstractItemModel::columnsRemoved, this, &QTransposeProxyModel::endRemoveRows),
+            connect(d->model, &QAbstractItemModel::columnsMoved, this, &QTransposeProxyModel::endMoveRows),
+            connect(d->model, &QAbstractItemModel::rowsAboutToBeInserted, this, std::bind(&QTransposeProxyModelPrivate::onRowsAboutToBeInserted, d, _1, _2, _3)),
+            connect(d->model, &QAbstractItemModel::rowsAboutToBeMoved, this, std::bind(&QTransposeProxyModelPrivate::onRowsAboutToBeMoved, d, _1, _2, _3, _4, _5)),
+            connect(d->model, &QAbstractItemModel::rowsAboutToBeRemoved, this, std::bind(&QTransposeProxyModelPrivate::onRowsAboutToBeRemoved, d, _1, _2, _3)),
+            connect(d->model, &QAbstractItemModel::rowsInserted, this, &QTransposeProxyModel::endInsertColumns),
+            connect(d->model, &QAbstractItemModel::rowsRemoved, this, &QTransposeProxyModel::endRemoveColumns),
+            connect(d->model, &QAbstractItemModel::rowsMoved, this, &QTransposeProxyModel::endMoveColumns),
+            connect(d->model, &QAbstractItemModel::layoutAboutToBeChanged, this, std::bind(&QTransposeProxyModelPrivate::onLayoutAboutToBeChanged, d, _1, _2)),
+            connect(d->model, &QAbstractItemModel::layoutChanged, this, std::bind(&QTransposeProxyModelPrivate::onLayoutChanged, d, _1, _2))
+        };
+    }
+    endResetModel();
+}
+
+/*!
+    \reimp
+*/
+int QTransposeProxyModel::rowCount(const QModelIndex &parent) const
+{
+    Q_D(const QTransposeProxyModel);
+    if (!d->model)
+        return 0;
+    Q_ASSERT(checkIndex(parent));
+    return d->model->columnCount(mapToSource(parent));
+}
+
+/*!
+    \reimp
+*/
+int QTransposeProxyModel::columnCount(const QModelIndex &parent) const
+{
+    Q_D(const QTransposeProxyModel);
+    if (!d->model)
+        return 0;
+    Q_ASSERT(checkIndex(parent));
+    return d->model->rowCount(mapToSource(parent));
+}
+
+/*!
+    \reimp
+*/
+QVariant QTransposeProxyModel::headerData(int section, Qt::Orientation orientation, int role) const
+{
+    Q_D(const QTransposeProxyModel);
+    if (!d->model)
+        return QVariant();
+    return d->model->headerData(section, orientation == Qt::Horizontal ? Qt::Vertical : Qt::Horizontal, role);
+}
+
+/*!
+    \reimp
+*/
+bool QTransposeProxyModel::setHeaderData(int section, Qt::Orientation orientation, const QVariant &value, int role)
+{
+    Q_D(QTransposeProxyModel);
+    if (!d->model)
+        return false;
+    return d->model->setHeaderData(section, orientation == Qt::Horizontal ? Qt::Vertical : Qt::Horizontal, value, role);
+}
+
+/*!
+    \reimp
+*/
+bool QTransposeProxyModel::setItemData(const QModelIndex &index, const QMap<int, QVariant> &roles)
+{
+    Q_D(QTransposeProxyModel);
+    Q_ASSERT(checkIndex(index));
+    if (!d->model || !index.isValid())
+        return false;
+    return d->model->setItemData(mapToSource(index), roles);
+}
+
+/*!
+    \reimp
+*/
+QSize QTransposeProxyModel::span(const QModelIndex &index) const
+{
+    Q_D(const QTransposeProxyModel);
+    Q_ASSERT(checkIndex(index));
+    if (!d->model || !index.isValid())
+        return QSize();
+    return d->model->span(mapToSource(index)).transposed();
+}
+
+/*!
+    \reimp
+*/
+QMap<int, QVariant> QTransposeProxyModel::itemData(const QModelIndex &index) const
+{
+    Q_D(const QTransposeProxyModel);
+    if (!d->model)
+        return QMap<int, QVariant>();
+    Q_ASSERT(checkIndex(index));
+    return d->model->itemData(mapToSource(index));
+}
+
+/*!
+    \reimp
+*/
+QModelIndex QTransposeProxyModel::mapFromSource(const QModelIndex &sourceIndex) const
+{
+    Q_D(const QTransposeProxyModel);
+    if (!d->model || !sourceIndex.isValid())
+        return QModelIndex();
+    Q_ASSERT(d->model->checkIndex(sourceIndex));
+    return d->uncheckedMapFromSource(sourceIndex);
+}
+
+/*!
+    \reimp
+*/
+QModelIndex QTransposeProxyModel::mapToSource(const QModelIndex &proxyIndex) const
+{
+    Q_D(const QTransposeProxyModel);
+    Q_ASSERT(checkIndex(proxyIndex));
+    if (!d->model || !proxyIndex.isValid())
+        return QModelIndex();
+    return d->uncheckedMapToSource(proxyIndex);
+}
+
+/*!
+    \reimp
+*/
+QModelIndex QTransposeProxyModel::parent(const QModelIndex &index) const
+{
+    Q_D(const QTransposeProxyModel);
+    Q_ASSERT(checkIndex(index, CheckIndexOption::DoNotUseParent));
+    if (!d->model || !index.isValid())
+        return QModelIndex();
+    return d->uncheckedMapFromSource(d->uncheckedMapToSource(index).parent());
+}
+
+/*!
+    \reimp
+*/
+QModelIndex QTransposeProxyModel::index(int row, int column, const QModelIndex &parent) const
+{
+    Q_D(const QTransposeProxyModel);
+    Q_ASSERT(checkIndex(parent));
+    if (!d->model)
+        return QModelIndex();
+    return mapFromSource(d->model->index(column, row, mapToSource(parent)));
+}
+
+/*!
+    \reimp
+*/
+bool QTransposeProxyModel::insertRows(int row, int count, const QModelIndex &parent)
+{
+    Q_D(QTransposeProxyModel);
+    Q_ASSERT(checkIndex(parent));
+    if (!d->model)
+        return false;
+    return d->model->insertColumns(row, count, mapToSource(parent));
+}
+
+/*!
+    \reimp
+*/
+bool QTransposeProxyModel::removeRows(int row, int count, const QModelIndex &parent)
+{
+    Q_D(QTransposeProxyModel);
+    Q_ASSERT(checkIndex(parent));
+    if (!d->model)
+        return false;
+    return d->model->removeColumns(row, count, mapToSource(parent));
+}
+
+/*!
+    \reimp
+*/
+bool QTransposeProxyModel::moveRows(const QModelIndex &sourceParent, int sourceRow, int count, const QModelIndex &destinationParent, int destinationChild)
+{
+    Q_D(QTransposeProxyModel);
+    Q_ASSERT(checkIndex(sourceParent));
+    Q_ASSERT(checkIndex(destinationParent));
+    if (!d->model)
+        return false;
+    return d->model->moveColumns(mapToSource(sourceParent), sourceRow, count, mapToSource(destinationParent), destinationChild);
+}
+
+/*!
+    \reimp
+*/
+bool QTransposeProxyModel::insertColumns(int column, int count, const QModelIndex &parent)
+{
+    Q_D(QTransposeProxyModel);
+    Q_ASSERT(checkIndex(parent));
+    if (!d->model)
+        return false;
+    return d->model->insertRows(column, count, mapToSource(parent));
+}
+
+/*!
+    \reimp
+*/
+bool QTransposeProxyModel::removeColumns(int column, int count, const QModelIndex &parent)
+{
+    Q_D(QTransposeProxyModel);
+    Q_ASSERT(checkIndex(parent));
+    if (!d->model)
+        return false;
+    return d->model->removeRows(column, count, mapToSource(parent));
+}
+
+/*!
+    \reimp
+*/
+bool QTransposeProxyModel::moveColumns(const QModelIndex &sourceParent, int sourceRow, int count, const QModelIndex &destinationParent, int destinationChild)
+{
+    Q_D(QTransposeProxyModel);
+    Q_ASSERT(checkIndex(sourceParent));
+    Q_ASSERT(checkIndex(destinationParent));
+    if (!d->model)
+        return false;
+    return d->model->moveRows(mapToSource(sourceParent), sourceRow, count, mapToSource(destinationParent), destinationChild);
+}
+
+/*!
+    \reimp
+    This method will perform no action. Use a QSortFilterProxyModel on top of this one if you require sorting.
+*/
+void QTransposeProxyModel::sort(int column, Qt::SortOrder order)
+{
+    Q_UNUSED(column)
+    Q_UNUSED(order)
+    return;
+}
+
+QT_END_NAMESPACE
diff --git a/src/corelib/itemmodels/qtransposeproxymodel.h b/src/corelib/itemmodels/qtransposeproxymodel.h
new file mode 100644
index 0000000000..879266d931
--- /dev/null
+++ b/src/corelib/itemmodels/qtransposeproxymodel.h
@@ -0,0 +1,83 @@
+/****************************************************************************
+**
+** Copyright (C) 2018 Luca Beldi <v.ronin@yahoo.it>
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the QtCore module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or (at your option) the GNU General
+** Public license version 3 or any later version approved by the KDE Free
+** Qt Foundation. The licenses are as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-2.0.html and
+** https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#ifndef QTRANSPOSEPROXYMODEL_H
+#define QTRANSPOSEPROXYMODEL_H
+
+#include <QtCore/qabstractproxymodel.h>
+#include <QtCore/qscopedpointer.h>
+
+QT_BEGIN_NAMESPACE
+
+class QTransposeProxyModelPrivate;
+
+class Q_CORE_EXPORT QTransposeProxyModel : public QAbstractProxyModel
+{
+    Q_OBJECT
+    Q_DISABLE_COPY(QTransposeProxyModel)
+    Q_DECLARE_PRIVATE(QTransposeProxyModel)
+public:
+    explicit QTransposeProxyModel(QObject* parent = nullptr);
+    ~QTransposeProxyModel();
+    void setSourceModel(QAbstractItemModel* newSourceModel) override;
+    int rowCount(const QModelIndex &parent = QModelIndex()) const override;
+    int columnCount(const QModelIndex &parent = QModelIndex()) const override;
+    QVariant headerData(int section, Qt::Orientation orientation, int role = Qt::DisplayRole) const override;
+    bool setHeaderData(int section, Qt::Orientation orientation, const QVariant &value, int role = Qt::EditRole) override;
+    bool setItemData(const QModelIndex &index, const QMap<int, QVariant> &roles) override;
+    QSize span(const QModelIndex &index) const override;
+    QMap<int, QVariant> itemData(const QModelIndex &index) const override;
+    QModelIndex mapFromSource(const QModelIndex &sourceIndex) const override;
+    QModelIndex mapToSource(const QModelIndex &proxyIndex) const override;
+    QModelIndex parent(const QModelIndex &index) const override;
+    QModelIndex index(int row, int column, const QModelIndex &parent = QModelIndex()) const override;
+    bool insertRows(int row, int count, const QModelIndex &parent = QModelIndex()) override;
+    bool removeRows(int row, int count, const QModelIndex &parent = QModelIndex()) override;
+    bool moveRows(const QModelIndex &sourceParent, int sourceRow, int count, const QModelIndex &destinationParent, int destinationChild) override;
+    bool insertColumns(int column, int count, const QModelIndex &parent = QModelIndex()) override;
+    bool removeColumns(int column, int count, const QModelIndex &parent = QModelIndex()) override;
+    bool moveColumns(const QModelIndex &sourceParent, int sourceColumn, int count, const QModelIndex &destinationParent, int destinationChild) override;
+    void sort(int column, Qt::SortOrder order = Qt::AscendingOrder) override;
+protected:
+    QTransposeProxyModel(QTransposeProxyModelPrivate &, QObject *parent);
+};
+
+QT_END_NAMESPACE
+
+#endif // QTRANSPOSEPROXYMODEL_H
diff --git a/src/corelib/itemmodels/qtransposeproxymodel_p.h b/src/corelib/itemmodels/qtransposeproxymodel_p.h
new file mode 100644
index 0000000000..240fc4ccae
--- /dev/null
+++ b/src/corelib/itemmodels/qtransposeproxymodel_p.h
@@ -0,0 +1,73 @@
+/****************************************************************************
+**
+** Copyright (C) 2018 Luca Beldi <v.ronin@yahoo.it>
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the QtCore module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or (at your option) the GNU General
+** Public license version 3 or any later version approved by the KDE Free
+** Qt Foundation. The licenses are as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-2.0.html and
+** https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#ifndef QTRANSPOSEPROXYMODEL_P_H
+#define QTRANSPOSEPROXYMODEL_P_H
+
+#include "qtransposeproxymodel.h"
+#include <private/qabstractproxymodel_p.h>
+
+QT_BEGIN_NAMESPACE
+
+class QTransposeProxyModelPrivate : public QAbstractProxyModelPrivate
+{
+    Q_DECLARE_PUBLIC(QTransposeProxyModel)
+    Q_DISABLE_COPY(QTransposeProxyModelPrivate)
+private:
+    QTransposeProxyModelPrivate() = default;
+    QVector<QMetaObject::Connection> sourceConnections;
+    QVector<QPersistentModelIndex> layoutChangePersistentIndexes;
+    QModelIndexList layoutChangeProxyIndexes;
+    QModelIndex uncheckedMapToSource(const QModelIndex &proxyIndex) const;
+    QModelIndex uncheckedMapFromSource(const QModelIndex &sourceIndex) const;
+    void onLayoutChanged(const QList<QPersistentModelIndex> &parents, QAbstractItemModel::LayoutChangeHint hint);
+    void onLayoutAboutToBeChanged(const QList<QPersistentModelIndex> &parents, QAbstractItemModel::LayoutChangeHint hint);
+    void onDataChanged(const QModelIndex& topLeft, const QModelIndex& bottomRight, const QVector<int>& roles);
+    void onHeaderDataChanged(Qt::Orientation orientation, int first, int last);
+    void onColumnsAboutToBeInserted(const QModelIndex &parent, int first, int last);
+    void onColumnsAboutToBeRemoved(const QModelIndex &parent, int first, int last);
+    void onColumnsAboutToBeMoved(const QModelIndex &sourceParent, int sourceStart, int sourceEnd, const QModelIndex &destinationParent, int destinationColumn);
+    void onRowsAboutToBeInserted(const QModelIndex &parent, int first, int last);
+    void onRowsAboutToBeRemoved(const QModelIndex &parent, int first, int last);
+    void onRowsAboutToBeMoved(const QModelIndex &sourceParent, int sourceStart, int sourceEnd, const QModelIndex &destinationParent, int destinationRow);
+};
+
+QT_END_NAMESPACE
+
+#endif //QTRANSPOSEPROXYMODEL_P_H
diff --git a/tests/auto/corelib/itemmodels/itemmodels.pro b/tests/auto/corelib/itemmodels/itemmodels.pro
index b27938e0c0..ffbda6ec40 100644
--- a/tests/auto/corelib/itemmodels/itemmodels.pro
+++ b/tests/auto/corelib/itemmodels/itemmodels.pro
@@ -9,6 +9,7 @@ qtHaveModule(gui): SUBDIRS += \
     qidentityproxymodel \
     qitemselectionmodel \
     qsortfilterproxymodel_recursive \
+    qtransposeproxymodel \
 
 qtHaveModule(widgets) {
     SUBDIRS += \
diff --git a/tests/auto/corelib/itemmodels/qtransposeproxymodel/qtransposeproxymodel.pro b/tests/auto/corelib/itemmodels/qtransposeproxymodel/qtransposeproxymodel.pro
new file mode 100644
index 0000000000..3834add115
--- /dev/null
+++ b/tests/auto/corelib/itemmodels/qtransposeproxymodel/qtransposeproxymodel.pro
@@ -0,0 +1,6 @@
+CONFIG += testcase
+TARGET = tst_qtransposeproxymodel
+QT = core gui testlib
+
+SOURCES = tst_qtransposeproxymodel.cpp
+
diff --git a/tests/auto/corelib/itemmodels/qtransposeproxymodel/tst_qtransposeproxymodel.cpp b/tests/auto/corelib/itemmodels/qtransposeproxymodel/tst_qtransposeproxymodel.cpp
new file mode 100644
index 0000000000..a30ac46571
--- /dev/null
+++ b/tests/auto/corelib/itemmodels/qtransposeproxymodel/tst_qtransposeproxymodel.cpp
@@ -0,0 +1,915 @@
+/****************************************************************************
+**
+** Copyright (C) 2018 Luca Beldi <v.ronin@yahoo.it>
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the QtCore module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or (at your option) the GNU General
+** Public license version 3 or any later version approved by the KDE Free
+** Qt Foundation. The licenses are as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-2.0.html and
+** https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include <QTest>
+#include <QSignalSpy>
+#include <QStandardItemModel>
+#include <QStringListModel>
+#include <QAbstractItemModelTester>
+#include <random>
+
+#include <qtransposeproxymodel.h>
+
+class tst_QTransposeProxyModel : public QObject
+{
+    Q_OBJECT
+private Q_SLOTS:
+    void initTestCase();
+    void index();
+    void data();
+    void setData_data();
+    void setData();
+    void parent();
+    void mapToSource();
+    void mapFromSource();
+    void basicTest_data();
+    void basicTest();
+    void sort();
+    void insertRowBase_data();
+    void insertRowBase();
+    void insertColumnBase_data();
+    void insertColumnBase();
+    void insertColumnProxy_data();
+    void insertColumnProxy();
+    void insertRowProxy_data();
+    void insertRowProxy();
+    void removeRowBase_data();
+    void removeRowBase();
+    void removeColumnBase_data();
+    void removeColumnBase();
+    void removeColumnProxy_data();
+    void removeColumnProxy();
+    void removeRowProxy_data();
+    void removeRowProxy();
+    void headerData();
+    void setHeaderData();
+    void span();
+    void itemData();
+    void setItemData();
+    void moveRowsBase();
+    void moveColumnsProxy();
+private:
+    void testTransposed(
+        const QAbstractItemModel *const baseModel,
+        const QAbstractItemModel *const transposed,
+        const QModelIndex &baseParent = QModelIndex(),
+        const QModelIndex &transposedParent = QModelIndex()
+    );
+    QAbstractItemModel *createListModel(QObject *parent);
+    QAbstractItemModel *createTableModel(QObject *parent);
+    QAbstractItemModel *createTreeModel(QObject *parent);
+};
+
+QAbstractItemModel *tst_QTransposeProxyModel::createListModel(QObject *parent)
+{
+    QStringList sequence;
+    sequence.reserve(10);
+    for (int i = 0; i < 10; ++i)
+        sequence.append(QString::number(i));
+    return new QStringListModel(sequence, parent);
+}
+
+QAbstractItemModel *tst_QTransposeProxyModel::createTableModel(QObject *parent)
+{
+    QAbstractItemModel *model = new QStandardItemModel(parent);
+    model->insertRows(0, 5);
+    model->insertColumns(0, 4);
+    for (int i = 0; i < model->rowCount(); ++i) {
+        for (int j = 0; j < model->columnCount(); ++j) {
+            model->setData(model->index(i, j), QStringLiteral("%1,%2").arg(i).arg(j), Qt::EditRole);
+            model->setData(model->index(i, j), i, Qt::UserRole);
+            model->setData(model->index(i, j), j, Qt::UserRole + 1);
+        }
+    }
+    return model;
+}
+
+QAbstractItemModel *tst_QTransposeProxyModel::createTreeModel(QObject *parent)
+{
+    QAbstractItemModel *model = new QStandardItemModel(parent);
+    model->insertRows(0, 5);
+    model->insertColumns(0, 4);
+    for (int i = 0; i < model->rowCount(); ++i) {
+        for (int j = 0; j < model->columnCount(); ++j) {
+            const QModelIndex parIdx = model->index(i, j);
+            model->setData(parIdx, QStringLiteral("%1,%2").arg(i).arg(j), Qt::EditRole);
+            model->setData(parIdx, i, Qt::UserRole);
+            model->setData(parIdx, j, Qt::UserRole + 1);
+            model->insertRows(0, 3, parIdx);
+            model->insertColumns(0, 2, parIdx);
+            for (int h = 0; h < model->rowCount(parIdx); ++h) {
+                for (int k = 0; k < model->columnCount(parIdx); ++k) {
+                    const QModelIndex childIdx = model->index(h, k, parIdx);
+                    model->setData(childIdx, QStringLiteral("%1,%2,%3,%4").arg(i).arg(j).arg(h).arg(k), Qt::EditRole);
+                    model->setData(childIdx, i, Qt::UserRole);
+                    model->setData(childIdx, j, Qt::UserRole + 1);
+                    model->setData(childIdx, h, Qt::UserRole + 2);
+                    model->setData(childIdx, k, Qt::UserRole + 3);
+                }
+            }
+        }
+    }
+    return model;
+}
+
+void tst_QTransposeProxyModel::testTransposed(
+    const QAbstractItemModel *const baseModel,
+    const QAbstractItemModel *const transposed,
+    const QModelIndex &baseParent,
+    const QModelIndex &transposedParent
+)
+{
+    QCOMPARE(transposed->hasChildren(transposedParent), baseModel->hasChildren(baseParent));
+    QCOMPARE(transposed->columnCount(transposedParent), baseModel->rowCount(baseParent));
+    QCOMPARE(transposed->rowCount(transposedParent), baseModel->columnCount(baseParent));
+    for (int i = 0, maxRow = baseModel->rowCount(baseParent); i < maxRow; ++i) {
+        for (int j = 0, maxCol = baseModel->columnCount(baseParent); j < maxCol; ++j) {
+            const QModelIndex baseIdx = baseModel->index(i, j, baseParent);
+            const QModelIndex transIdx = transposed->index(j, i, transposedParent);
+            QCOMPARE(transIdx.data(), baseIdx.data());
+            QCOMPARE(transIdx.data(Qt::UserRole), baseIdx.data(Qt::UserRole));
+            QCOMPARE(transIdx.data(Qt::UserRole + 1), baseIdx.data(Qt::UserRole + 1));
+            QCOMPARE(transIdx.data(Qt::UserRole + 2), baseIdx.data(Qt::UserRole + 2));
+            QCOMPARE(transIdx.data(Qt::UserRole + 3), baseIdx.data(Qt::UserRole + 3));
+            if (baseModel->hasChildren(baseIdx)) {
+                testTransposed(baseModel, transposed, baseIdx, transIdx);
+            }
+        }
+    }
+}
+
+void tst_QTransposeProxyModel::initTestCase()
+{
+    qRegisterMetaType<QList<QPersistentModelIndex> >();
+    qRegisterMetaType<QAbstractItemModel::LayoutChangeHint>();
+}
+
+void tst_QTransposeProxyModel::index()
+{
+    QAbstractItemModel *model = createTreeModel(this);
+    QTransposeProxyModel proxy;
+    new QAbstractItemModelTester(&proxy, &proxy);
+    proxy.setSourceModel(model);
+    QVERIFY(!proxy.index(0, -1).isValid());
+    QVERIFY(!proxy.index(0, -1).isValid());
+    QVERIFY(!proxy.index(-1, -1).isValid());
+    QVERIFY(!proxy.index(0, proxy.columnCount()).isValid());
+    QVERIFY(!proxy.index(proxy.rowCount(), 0).isValid());
+    QVERIFY(!proxy.index(proxy.rowCount(), proxy.columnCount()).isValid());
+    QModelIndex tempIdx = proxy.index(0, 1);
+    QVERIFY(tempIdx.isValid());
+    QCOMPARE(tempIdx.row(), 0);
+    QCOMPARE(tempIdx.column(), 1);
+    tempIdx = proxy.index(0, 1, tempIdx);
+    QVERIFY(tempIdx.isValid());
+    QCOMPARE(tempIdx.row(), 0);
+    QCOMPARE(tempIdx.column(), 1);
+    delete model;
+}
+
+void tst_QTransposeProxyModel::data()
+{
+    QStringListModel model{QStringList{"A", "B"}};
+    QTransposeProxyModel proxy;
+    new QAbstractItemModelTester(&proxy, &proxy);
+    proxy.setSourceModel(&model);
+    QCOMPARE(proxy.index(0, 1).data().toString(), QStringLiteral("B"));
+}
+
+void tst_QTransposeProxyModel::parent()
+{
+    QAbstractItemModel *model = createTreeModel(this);
+    QTransposeProxyModel proxy;
+    new QAbstractItemModelTester(&proxy, &proxy);
+    proxy.setSourceModel(model);
+    const QModelIndex parentIdx = proxy.index(0, 0);
+    const QModelIndex childIdx = proxy.index(0, 0, parentIdx);
+    QVERIFY(parentIdx.isValid());
+    QVERIFY(childIdx.isValid());
+    QCOMPARE(childIdx.parent(), parentIdx);
+    delete model;
+}
+
+void tst_QTransposeProxyModel::mapToSource()
+{
+    QAbstractItemModel *model = createTreeModel(this);
+    QTransposeProxyModel proxy;
+    new QAbstractItemModelTester(&proxy, &proxy);
+    proxy.setSourceModel(model);
+    QVERIFY(!proxy.mapToSource(QModelIndex()).isValid());
+    QCOMPARE(proxy.mapToSource(proxy.index(0, 0)), model->index(0, 0));
+    QCOMPARE(proxy.mapToSource(proxy.index(1, 0)), model->index(0, 1));
+    QCOMPARE(proxy.mapToSource(proxy.index(0, 1)), model->index(1, 0));
+    const QModelIndex proxyParent = proxy.index(1, 0);
+    const QModelIndex sourceParent = model->index(0, 1);
+    QCOMPARE(proxy.mapToSource(proxy.index(0, 0, proxyParent)), model->index(0, 0, sourceParent));
+    QCOMPARE(proxy.mapToSource(proxy.index(1, 0, proxyParent)), model->index(0, 1, sourceParent));
+    QCOMPARE(proxy.mapToSource(proxy.index(0, 1, proxyParent)), model->index(1, 0, sourceParent));
+    delete model;
+}
+
+void tst_QTransposeProxyModel::mapFromSource()
+{
+    QAbstractItemModel *model = createTreeModel(this);
+    QTransposeProxyModel proxy;
+    new QAbstractItemModelTester(&proxy, &proxy);
+    proxy.setSourceModel(model);
+    QVERIFY(!proxy.mapFromSource(QModelIndex()).isValid());
+    QCOMPARE(proxy.mapFromSource(model->index(0, 0)), proxy.index(0, 0));
+    QCOMPARE(proxy.mapFromSource(model->index(0, 1)), proxy.index(1, 0));
+    QCOMPARE(proxy.mapFromSource(model->index(1, 0)), proxy.index(0, 1));
+    const QModelIndex proxyParent = proxy.index(1, 0);
+    const QModelIndex sourceParent = model->index(0, 1);
+    QCOMPARE(proxy.mapToSource(proxy.index(0, 0, proxyParent)), model->index(0, 0, sourceParent));
+    QCOMPARE(proxy.mapFromSource(model->index(1, 0, sourceParent)), proxy.index(0, 1, proxyParent));
+    QCOMPARE(proxy.mapFromSource(model->index(0, 1, sourceParent)), proxy.index(1, 0, proxyParent));
+    delete model;
+}
+
+void tst_QTransposeProxyModel::basicTest_data()
+{
+    QTest::addColumn<QAbstractItemModel *>("model");
+    QTest::newRow("List") << createListModel(this);
+    QTest::newRow("Table") << createTableModel(this);
+    QTest::newRow("Tree") << createTreeModel(this);
+}
+
+void tst_QTransposeProxyModel::basicTest()
+{
+    QFETCH(QAbstractItemModel *, model);
+    QTransposeProxyModel proxy;
+    new QAbstractItemModelTester(&proxy, &proxy);
+    proxy.setSourceModel(model);
+    testTransposed(model, &proxy);
+    delete model;
+}
+
+void tst_QTransposeProxyModel::sort()
+{
+    QStringList sequence;
+    sequence.reserve(100);
+    for (int i = 0; i < 100; ++i)
+        sequence.append(QStringLiteral("%1").arg(i, 3, 10, QLatin1Char('0')));
+    std::shuffle(sequence.begin(), sequence.end(), std::mt19937(88));
+    const QString firstItemBeforeSort = sequence.first();
+    QStringListModel baseModel(sequence);
+    QTransposeProxyModel proxyModel;
+    new QAbstractItemModelTester(&proxyModel, &proxyModel);
+    proxyModel.setSourceModel(&baseModel);
+    QSignalSpy layoutChangedSpy(&proxyModel, &QAbstractItemModel::layoutChanged);
+    QVERIFY(layoutChangedSpy.isValid());
+    QSignalSpy layoutAboutToBeChangedSpy(&proxyModel, &QAbstractItemModel::layoutAboutToBeChanged);
+    QVERIFY(layoutAboutToBeChangedSpy.isValid());
+    QPersistentModelIndex firstIndexBeforeSort = proxyModel.index(0, 0);
+    baseModel.sort(0, Qt::AscendingOrder);
+    QCOMPARE(layoutChangedSpy.count(), 1);
+    QCOMPARE(layoutAboutToBeChangedSpy.count(), 1);
+    QCOMPARE(layoutChangedSpy.takeFirst().at(1).toInt(), int(QAbstractItemModel::HorizontalSortHint));
+    QCOMPARE(firstIndexBeforeSort.data().toString(), firstItemBeforeSort);
+    for (int i = 0; i < 100; ++i)
+        QCOMPARE(proxyModel.index(0, i).data().toInt(), i);
+}
+
+void tst_QTransposeProxyModel::removeColumnBase_data()
+{
+    QTest::addColumn<QAbstractItemModel *>("model");
+    QTest::addColumn<QModelIndex>("parent");
+    QTest::newRow("Table") << createTableModel(this) << QModelIndex();
+    QTest::newRow("Tree_Root_Item") << createTreeModel(this) << QModelIndex();
+    QAbstractItemModel *model = createTreeModel(this);
+    QTest::newRow("Tree_Child_Item") << model << model->index(0, 0);
+}
+
+void tst_QTransposeProxyModel::removeColumnBase()
+{
+    QFETCH(QAbstractItemModel * const, model);
+    QFETCH(const QModelIndex, parent);
+    QTransposeProxyModel proxy;
+    QSignalSpy rowRemoveSpy(&proxy, &QAbstractItemModel::rowsRemoved);
+    QVERIFY(rowRemoveSpy.isValid());
+    QSignalSpy rowAboutToBeRemoveSpy(&proxy, &QAbstractItemModel::rowsAboutToBeRemoved);
+    QVERIFY(rowAboutToBeRemoveSpy.isValid());
+    new QAbstractItemModelTester(&proxy, &proxy);
+    proxy.setSourceModel(model);
+    const int oldRowCount = proxy.rowCount(proxy.mapFromSource(parent));
+    const QVariant expectedNewVal = model->index(0, 2, parent).data();
+    QVERIFY(model->removeColumn(1, parent));
+    QCOMPARE(proxy.rowCount(proxy.mapFromSource(parent)), oldRowCount - 1);
+    QCOMPARE(proxy.index(1, 0, proxy.mapFromSource(parent)).data(), expectedNewVal);
+    QCOMPARE(rowRemoveSpy.count(), 1);
+    QCOMPARE(rowAboutToBeRemoveSpy.count(), 1);
+    for (const auto &spyArgs : {rowRemoveSpy.takeFirst(),
+        rowAboutToBeRemoveSpy.takeFirst()}) {
+        QCOMPARE(spyArgs.at(0).value<QModelIndex>(), proxy.mapFromSource(parent));
+        QCOMPARE(spyArgs.at(1).toInt(), 1);
+        QCOMPARE(spyArgs.at(2).toInt(), 1);
+    }
+    delete model;
+}
+
+void tst_QTransposeProxyModel::insertColumnBase_data()
+{
+    QTest::addColumn<QAbstractItemModel *>("model");
+    QTest::addColumn<QModelIndex>("parent");
+    QTest::newRow("Table") << createTableModel(this) << QModelIndex();
+    QTest::newRow("Tree_Root_Item") << createTreeModel(this) << QModelIndex();
+    QAbstractItemModel *model = createTreeModel(this);
+    QTest::newRow("Tree_Child_Item") << model << model->index(0, 0);
+}
+
+void tst_QTransposeProxyModel::insertColumnBase()
+{
+    QFETCH(QAbstractItemModel * const, model);
+    QFETCH(const QModelIndex, parent);
+    QTransposeProxyModel proxy;
+    QSignalSpy rowInsertSpy(&proxy, &QAbstractItemModel::rowsInserted);
+    QVERIFY(rowInsertSpy.isValid());
+    QSignalSpy rowAboutToBeInsertSpy(&proxy, &QAbstractItemModel::rowsAboutToBeInserted);
+    QVERIFY(rowAboutToBeInsertSpy.isValid());
+    new QAbstractItemModelTester(&proxy, &proxy);
+    proxy.setSourceModel(model);
+    const int oldRowCount = proxy.rowCount(proxy.mapFromSource(parent));
+    QVERIFY(model->insertColumn(1, parent));
+    QCOMPARE(proxy.rowCount(proxy.mapFromSource(parent)), oldRowCount + 1);
+    QVERIFY(!proxy.index(1, 0, proxy.mapFromSource(parent)).data().isValid());
+    QCOMPARE(rowInsertSpy.count(), 1);
+    QCOMPARE(rowAboutToBeInsertSpy.count(), 1);
+    for (const auto &spyArgs : {rowInsertSpy.takeFirst(),
+        rowAboutToBeInsertSpy.takeFirst()}) {
+        QCOMPARE(spyArgs.at(0).value<QModelIndex>(), proxy.mapFromSource(parent));
+        QCOMPARE(spyArgs.at(1).toInt(), 1);
+        QCOMPARE(spyArgs.at(2).toInt(), 1);
+    }
+    delete model;
+}
+
+void tst_QTransposeProxyModel::removeRowBase_data()
+{
+    QTest::addColumn<QAbstractItemModel *>("model");
+    QTest::addColumn<QModelIndex>("parent");
+    QTest::newRow("List") << createListModel(this) << QModelIndex();
+    QTest::newRow("Table") << createTableModel(this) << QModelIndex();
+    QTest::newRow("Tree_Root_Item") << createTreeModel(this) << QModelIndex();
+    QAbstractItemModel *model = createTreeModel(this);
+    QTest::newRow("Tree_Child_Item") << model << model->index(0, 0);
+}
+
+void tst_QTransposeProxyModel::removeRowBase()
+{
+    QFETCH(QAbstractItemModel * const, model);
+    QFETCH(const QModelIndex, parent);
+    QTransposeProxyModel proxy;
+    QSignalSpy columnsRemoveSpy(&proxy, &QAbstractItemModel::columnsRemoved);
+    QVERIFY(columnsRemoveSpy.isValid());
+    QSignalSpy columnsAboutToBeRemoveSpy(&proxy, &QAbstractItemModel::columnsAboutToBeRemoved);
+    QVERIFY(columnsAboutToBeRemoveSpy.isValid());
+    new QAbstractItemModelTester(&proxy, &proxy);
+    proxy.setSourceModel(model);
+    const int oldColCount = proxy.columnCount(proxy.mapFromSource(parent));
+    const QVariant expectedNewVal = model->index(2, 0, parent).data();
+    QVERIFY(model->removeRow(1, parent));
+    QCOMPARE(proxy.columnCount(proxy.mapFromSource(parent)), oldColCount - 1);
+    QCOMPARE(proxy.index(0, 1, proxy.mapFromSource(parent)).data(), expectedNewVal);
+    QCOMPARE(columnsRemoveSpy.count(), 1);
+    QCOMPARE(columnsAboutToBeRemoveSpy.count(), 1);
+    for (const auto &spyArgs : {columnsRemoveSpy.takeFirst(),
+        columnsAboutToBeRemoveSpy.takeFirst()}) {
+        QCOMPARE(spyArgs.at(0).value<QModelIndex>(), proxy.mapFromSource(parent));
+        QCOMPARE(spyArgs.at(1).toInt(), 1);
+        QCOMPARE(spyArgs.at(2).toInt(), 1);
+    }
+    delete model;
+}
+
+void tst_QTransposeProxyModel::insertRowBase_data()
+{
+    QTest::addColumn<QAbstractItemModel *>("model");
+    QTest::addColumn<QModelIndex>("parent");
+    QTest::newRow("List") << createListModel(this) << QModelIndex();
+    QTest::newRow("Table") << createTableModel(this) << QModelIndex();
+    QTest::newRow("Tree_Root_Item") << createTreeModel(this) << QModelIndex();
+    QAbstractItemModel *model = createTreeModel(this);
+    QTest::newRow("Tree_Child_Item") << model << model->index(0, 0);
+}
+
+void tst_QTransposeProxyModel::insertRowBase()
+{
+    QFETCH(QAbstractItemModel * const, model);
+    QFETCH(const QModelIndex, parent);
+    QTransposeProxyModel proxy;
+    QSignalSpy columnsInsertSpy(&proxy, &QAbstractItemModel::columnsInserted);
+    QVERIFY(columnsInsertSpy.isValid());
+    QSignalSpy columnsAboutToBeInsertSpy(&proxy, &QAbstractItemModel::columnsAboutToBeInserted);
+    QVERIFY(columnsAboutToBeInsertSpy.isValid());
+    new QAbstractItemModelTester(&proxy, &proxy);
+    proxy.setSourceModel(model);
+    const int oldColCount = proxy.columnCount(proxy.mapFromSource(parent));
+    QVERIFY(model->insertRow(1, parent));
+    QCOMPARE(proxy.columnCount(proxy.mapFromSource(parent)), oldColCount + 1);
+    QVERIFY(proxy.index(0, 1, proxy.mapFromSource(parent)).data().isNull());
+    QCOMPARE(columnsInsertSpy.count(), 1);
+    QCOMPARE(columnsAboutToBeInsertSpy.count(), 1);
+    for (const auto &spyArgs : {columnsInsertSpy.takeFirst(),
+        columnsAboutToBeInsertSpy.takeFirst()}) {
+        QCOMPARE(spyArgs.at(0).value<QModelIndex>(), proxy.mapFromSource(parent));
+        QCOMPARE(spyArgs.at(1).toInt(), 1);
+        QCOMPARE(spyArgs.at(2).toInt(), 1);
+    }
+    delete model;
+}
+
+void tst_QTransposeProxyModel::removeColumnProxy_data()
+{
+    QTest::addColumn<QAbstractItemModel *>("model");
+    QTest::addColumn<bool>("rootItem");
+    QTest::newRow("List") << createListModel(this) << true;
+    QTest::newRow("Table") << createTableModel(this) << true;
+    QTest::newRow("Tree_Root_Item") << createTreeModel(this) << true;
+    QTest::newRow("Tree_Child_Item") << createTreeModel(this) << false;
+}
+
+void tst_QTransposeProxyModel::removeColumnProxy()
+{
+    QFETCH(QAbstractItemModel *, model);
+    QFETCH(bool, rootItem);
+    QTransposeProxyModel proxy;
+    new QAbstractItemModelTester(&proxy, &proxy);
+    QSignalSpy columnsRemoveSpy(&proxy, &QAbstractItemModel::columnsRemoved);
+    QVERIFY(columnsRemoveSpy.isValid());
+    QSignalSpy columnsAboutToBeRemoveSpy(&proxy, &QAbstractItemModel::columnsAboutToBeRemoved);
+    QVERIFY(columnsAboutToBeRemoveSpy.isValid());
+    QSignalSpy rowsRemoveSpy(model, &QAbstractItemModel::rowsRemoved);
+    QVERIFY(rowsRemoveSpy.isValid());
+    QSignalSpy rowsAboutToBeRemoveSpy(model, &QAbstractItemModel::rowsAboutToBeRemoved);
+    QVERIFY(rowsAboutToBeRemoveSpy.isValid());
+    proxy.setSourceModel(model);
+    const QModelIndex proxyParent = rootItem ? QModelIndex() : proxy.index(0, 1);
+    const QModelIndex sourceParent = proxy.mapToSource(proxyParent);
+    const int oldColCount = proxy.columnCount(proxyParent);
+    const int oldRowCount = model->rowCount(sourceParent);
+    const QVariant expectedNewVal = proxy.index(0, 2, proxyParent).data();
+    QVERIFY(proxy.removeColumn(1, proxyParent));
+    QCOMPARE(proxy.columnCount(proxyParent), oldColCount - 1);
+    QCOMPARE(model->rowCount(sourceParent), oldRowCount - 1);
+    QCOMPARE(proxy.index(0, 1, proxyParent).data(), expectedNewVal);
+    QCOMPARE(model->index(1, 0, sourceParent).data(), expectedNewVal);
+    QCOMPARE(columnsRemoveSpy.count(), 1);
+    QCOMPARE(columnsAboutToBeRemoveSpy.count(), 1);
+    QCOMPARE(rowsRemoveSpy.count(), 1);
+    QCOMPARE(rowsAboutToBeRemoveSpy.count(), 1);
+    for (const auto &spyArgs : {columnsRemoveSpy.takeFirst(),
+        columnsAboutToBeRemoveSpy.takeFirst()}) {
+        QCOMPARE(spyArgs.at(0).value<QModelIndex>(), proxyParent);
+        QCOMPARE(spyArgs.at(1).toInt(), 1);
+        QCOMPARE(spyArgs.at(2).toInt(), 1);
+    }
+    for (const auto &spyArgs : {rowsRemoveSpy.takeFirst(),
+        rowsAboutToBeRemoveSpy.takeFirst()}) {
+        QCOMPARE(spyArgs.at(0).value<QModelIndex>(), sourceParent);
+        QCOMPARE(spyArgs.at(1).toInt(), 1);
+        QCOMPARE(spyArgs.at(2).toInt(), 1);
+    }
+    delete model;
+}
+
+void tst_QTransposeProxyModel::insertColumnProxy_data()
+{
+    QTest::addColumn<QAbstractItemModel *>("model");
+    QTest::addColumn<bool>("rootItem");
+    QTest::newRow("List") << createListModel(this) << true;
+    QTest::newRow("Table") << createTableModel(this) << true;
+    QTest::newRow("Tree_Root_Item") << createTreeModel(this) << true;
+    QTest::newRow("Tree_Child_Item") << createTreeModel(this) << false;
+}
+
+void tst_QTransposeProxyModel::insertColumnProxy()
+{
+    QFETCH(QAbstractItemModel *, model);
+    QFETCH(bool, rootItem);
+    QTransposeProxyModel proxy;
+    new QAbstractItemModelTester(&proxy, &proxy);
+    QSignalSpy columnsInsertSpy(&proxy, &QAbstractItemModel::columnsInserted);
+    QVERIFY(columnsInsertSpy.isValid());
+    QSignalSpy columnsAboutToBeInsertSpy(&proxy, &QAbstractItemModel::columnsAboutToBeInserted);
+    QVERIFY(columnsAboutToBeInsertSpy.isValid());
+    QSignalSpy rowsInsertSpy(model, &QAbstractItemModel::rowsInserted);
+    QVERIFY(rowsInsertSpy.isValid());
+    QSignalSpy rowsAboutToBeInsertSpy(model, &QAbstractItemModel::rowsAboutToBeInserted);
+    QVERIFY(rowsAboutToBeInsertSpy.isValid());
+    proxy.setSourceModel(model);
+    const QModelIndex proxyParent = rootItem ? QModelIndex() : proxy.index(0, 1);
+    const QModelIndex sourceParent = proxy.mapToSource(proxyParent);
+    const int oldColCount = proxy.columnCount(proxyParent);
+    const int oldRowCount = model->rowCount(sourceParent);
+    QVERIFY(proxy.insertColumn(1, proxyParent));
+    QCOMPARE(proxy.columnCount(proxyParent), oldColCount + 1);
+    QCOMPARE(model->rowCount(sourceParent), oldRowCount + 1);
+    QVERIFY(proxy.index(0, 1, proxyParent).data().isNull());
+    QVERIFY(model->index(1, 0, sourceParent).data().isNull());
+    QCOMPARE(columnsInsertSpy.count(), 1);
+    QCOMPARE(columnsAboutToBeInsertSpy.count(), 1);
+    QCOMPARE(rowsInsertSpy.count(), 1);
+    QCOMPARE(rowsAboutToBeInsertSpy.count(), 1);
+    for (const auto &spyArgs : {columnsInsertSpy.takeFirst(),
+        columnsAboutToBeInsertSpy.takeFirst()}) {
+        QCOMPARE(spyArgs.at(0).value<QModelIndex>(), proxyParent);
+        QCOMPARE(spyArgs.at(1).toInt(), 1);
+        QCOMPARE(spyArgs.at(2).toInt(), 1);
+    }
+    for (const auto &spyArgs : {rowsInsertSpy.takeFirst(),
+        rowsAboutToBeInsertSpy.takeFirst()}) {
+        QCOMPARE(spyArgs.at(0).value<QModelIndex>(), sourceParent);
+        QCOMPARE(spyArgs.at(1).toInt(), 1);
+        QCOMPARE(spyArgs.at(2).toInt(), 1);
+    }
+    delete model;
+}
+
+void tst_QTransposeProxyModel::removeRowProxy_data()
+{
+    QTest::addColumn<QAbstractItemModel *>("model");
+    QTest::addColumn<bool>("rootItem");
+    QTest::newRow("Table") << createTableModel(this) << true;
+    QTest::newRow("Tree_Root_Item") << createTreeModel(this) << true;
+    QTest::newRow("Tree_Child_Item") << createTreeModel(this) << false;
+}
+
+void tst_QTransposeProxyModel::removeRowProxy()
+{
+    QFETCH(QAbstractItemModel *, model);
+    QFETCH(bool, rootItem);
+    QTransposeProxyModel proxy;
+    new QAbstractItemModelTester(&proxy, &proxy);
+    QSignalSpy rowsRemoveSpy(&proxy, &QAbstractItemModel::rowsRemoved);
+    QVERIFY(rowsRemoveSpy.isValid());
+    QSignalSpy rowsAboutToBeRemoveSpy(&proxy, &QAbstractItemModel::rowsAboutToBeRemoved);
+    QVERIFY(rowsAboutToBeRemoveSpy.isValid());
+    QSignalSpy columnsRemoveSpy(model, &QAbstractItemModel::columnsRemoved);
+    QVERIFY(columnsRemoveSpy.isValid());
+    QSignalSpy columnsAboutToBeRemoveSpy(model, &QAbstractItemModel::columnsAboutToBeRemoved);
+    QVERIFY(columnsAboutToBeRemoveSpy.isValid());
+    proxy.setSourceModel(model);
+    const QModelIndex proxyParent = rootItem ? QModelIndex() : proxy.index(0, 1);
+    const QModelIndex sourceParent = proxy.mapToSource(proxyParent);
+    const int oldRowCount = proxy.rowCount(proxyParent);
+    const int oldColCount = model->columnCount(sourceParent);
+    const QVariant expectedNewVal = proxy.index(2, 0, proxyParent).data();
+    QVERIFY(proxy.removeRow(1, proxyParent));
+    QCOMPARE(proxy.rowCount(proxyParent), oldRowCount - 1);
+    QCOMPARE(model->columnCount(sourceParent), oldColCount - 1);
+    QCOMPARE(proxy.index(1, 0, proxyParent).data(), expectedNewVal);
+    QCOMPARE(model->index(0, 1, sourceParent).data(), expectedNewVal);
+    QCOMPARE(columnsRemoveSpy.count(), 1);
+    QCOMPARE(columnsAboutToBeRemoveSpy.count(), 1);
+    QCOMPARE(rowsRemoveSpy.count(), 1);
+    QCOMPARE(rowsAboutToBeRemoveSpy.count(), 1);
+    for (const auto &spyArgs : {columnsRemoveSpy.takeFirst(),
+        columnsAboutToBeRemoveSpy.takeFirst()}) {
+        QCOMPARE(spyArgs.at(0).value<QModelIndex>(), sourceParent);
+        QCOMPARE(spyArgs.at(1).toInt(), 1);
+        QCOMPARE(spyArgs.at(2).toInt(), 1);
+    }
+    for (const auto &spyArgs : {rowsRemoveSpy.takeFirst(),
+        rowsAboutToBeRemoveSpy.takeFirst()}) {
+        QCOMPARE(spyArgs.at(0).value<QModelIndex>(), proxyParent);
+        QCOMPARE(spyArgs.at(1).toInt(), 1);
+        QCOMPARE(spyArgs.at(2).toInt(), 1);
+    }
+    delete model;
+}
+
+void tst_QTransposeProxyModel::insertRowProxy_data()
+{
+    QTest::addColumn<QAbstractItemModel *>("model");
+    QTest::addColumn<bool>("rootItem");
+    QTest::newRow("Table") << createTableModel(this) << true;
+    QTest::newRow("Tree_Root_Item") << createTreeModel(this) << true;
+    QTest::newRow("Tree_Child_Item") << createTreeModel(this) << false;
+}
+
+void tst_QTransposeProxyModel::insertRowProxy()
+{
+    QFETCH(QAbstractItemModel *, model);
+    QFETCH(bool, rootItem);
+    QTransposeProxyModel proxy;
+    new QAbstractItemModelTester(&proxy, &proxy);
+    QSignalSpy rowsInsertSpy(&proxy, &QAbstractItemModel::rowsInserted);
+    QVERIFY(rowsInsertSpy.isValid());
+    QSignalSpy rowsAboutToBeInsertSpy(&proxy, &QAbstractItemModel::rowsAboutToBeInserted);
+    QVERIFY(rowsAboutToBeInsertSpy.isValid());
+    QSignalSpy columnsInsertSpy(model, &QAbstractItemModel::columnsInserted);
+    QVERIFY(columnsInsertSpy.isValid());
+    QSignalSpy columnsAboutToBeInsertSpy(model, &QAbstractItemModel::columnsAboutToBeInserted);
+    QVERIFY(columnsAboutToBeInsertSpy.isValid());
+    proxy.setSourceModel(model);
+    const QModelIndex proxyParent = rootItem ? QModelIndex() : proxy.index(0, 1);
+    const QModelIndex sourceParent = proxy.mapToSource(proxyParent);
+    const int oldRowCount = proxy.rowCount(proxyParent);
+    const int oldColCount = model->columnCount(sourceParent);
+    QVERIFY(proxy.insertRow(1, proxyParent));
+    QCOMPARE(proxy.rowCount(proxyParent), oldRowCount + 1);
+    QCOMPARE(model->columnCount(sourceParent), oldColCount + 1);
+    QVERIFY(proxy.index(1, 0, proxyParent).data().isNull());
+    QVERIFY(model->index(0, 1, sourceParent).data().isNull());
+    QCOMPARE(columnsInsertSpy.count(), 1);
+    QCOMPARE(columnsAboutToBeInsertSpy.count(), 1);
+    QCOMPARE(rowsInsertSpy.count(), 1);
+    QCOMPARE(rowsAboutToBeInsertSpy.count(), 1);
+    for (const auto &spyArgs : {columnsInsertSpy.takeFirst(),
+        columnsAboutToBeInsertSpy.takeFirst()}) {
+        QCOMPARE(spyArgs.at(0).value<QModelIndex>(), sourceParent);
+        QCOMPARE(spyArgs.at(1).toInt(), 1);
+        QCOMPARE(spyArgs.at(2).toInt(), 1);
+    }
+    for (const auto &spyArgs : {rowsInsertSpy.takeFirst(),
+        rowsAboutToBeInsertSpy.takeFirst()}) {
+        QCOMPARE(spyArgs.at(0).value<QModelIndex>(), proxyParent);
+        QCOMPARE(spyArgs.at(1).toInt(), 1);
+        QCOMPARE(spyArgs.at(2).toInt(), 1);
+    }
+    delete model;
+}
+
+void tst_QTransposeProxyModel::headerData()
+{
+    QStandardItemModel model;
+    model.insertRows(0, 3);
+    model.insertColumns(0, 5);
+    for (int i = 0; i < model.rowCount(); ++i)
+        model.setHeaderData(i, Qt::Horizontal, QChar('A' + i));
+    for (int i = 1; i <= model.columnCount(); ++i)
+        model.setHeaderData(i, Qt::Vertical, i);
+    QTransposeProxyModel proxy;
+    new QAbstractItemModelTester(&proxy, &proxy);
+    proxy.setSourceModel(&model);
+    for (int i = 0; i < model.rowCount(); ++i)
+        QCOMPARE(model.headerData(i, Qt::Horizontal), proxy.headerData(i, Qt::Vertical));
+    for (int i = 0; i < model.columnCount(); ++i)
+        QCOMPARE(model.headerData(i, Qt::Vertical), proxy.headerData(i, Qt::Horizontal));
+}
+
+void tst_QTransposeProxyModel::setHeaderData()
+{
+    QStandardItemModel model;
+    model.insertRows(0, 3);
+    model.insertColumns(0, 5);
+    for (int i = 0; i < model.rowCount(); ++i)
+        model.setHeaderData(i, Qt::Horizontal, QChar('A' + i));
+    for (int i = 1; i <= model.columnCount(); ++i)
+        model.setHeaderData(i, Qt::Vertical, i);
+    QTransposeProxyModel proxy;
+    new QAbstractItemModelTester(&proxy, &proxy);
+    proxy.setSourceModel(&model);
+    QVERIFY(proxy.setHeaderData(1, Qt::Horizontal, 99));
+    QCOMPARE(model.headerData(1, Qt::Vertical).toInt(), 99);
+    QVERIFY(proxy.setHeaderData(1, Qt::Vertical, QChar('Z')));
+    QCOMPARE(model.headerData(1, Qt::Horizontal).toChar(), QChar('Z'));
+}
+
+void tst_QTransposeProxyModel::span()
+{
+    class SpanModel : public QStandardItemModel
+    {
+        Q_DISABLE_COPY(SpanModel)
+    public:
+        SpanModel(int rows, int columns, QObject *parent = nullptr)
+            : QStandardItemModel(rows, columns, parent)
+        {}
+        QSize span(const QModelIndex &index) const override
+        {
+            Q_UNUSED(index)
+            return QSize(2, 1);
+        }
+    };
+    SpanModel model(3, 5);
+    QTransposeProxyModel proxy;
+    new QAbstractItemModelTester(&proxy, &proxy);
+    proxy.setSourceModel(&model);
+    QCOMPARE(proxy.span(proxy.index(0, 0)), QSize(1, 2));
+}
+
+void tst_QTransposeProxyModel::itemData()
+{
+    QAbstractItemModel *model = createTreeModel(this);
+    QTransposeProxyModel proxy;
+    new QAbstractItemModelTester(&proxy, &proxy);
+    proxy.setSourceModel(model);
+    QMap<int, QVariant> itmData = proxy.itemData(proxy.index(0, 1));
+    QCOMPARE(itmData.value(Qt::DisplayRole).toString(), QStringLiteral("1,0"));
+    QCOMPARE(itmData.value(Qt::UserRole).toInt(), 1);
+    QCOMPARE(itmData.value(Qt::UserRole + 1).toInt(), 0);
+    itmData = proxy.itemData(proxy.index(1, 2, proxy.index(0, 1)));
+    QCOMPARE(itmData.value(Qt::DisplayRole).toString(), QStringLiteral("1,0,2,1"));
+    QCOMPARE(itmData.value(Qt::UserRole).toInt(), 1);
+    QCOMPARE(itmData.value(Qt::UserRole + 1).toInt(), 0);
+    QCOMPARE(itmData.value(Qt::UserRole + 2).toInt(), 2);
+    QCOMPARE(itmData.value(Qt::UserRole + 3).toInt(), 1);
+    QVERIFY(proxy.itemData(QModelIndex()).isEmpty());
+    delete model;
+}
+
+void tst_QTransposeProxyModel::setItemData()
+{
+    QAbstractItemModel *model = createTreeModel(this);
+    QTransposeProxyModel proxy;
+    new QAbstractItemModelTester(&proxy, &proxy);
+    proxy.setSourceModel(model);
+    QSignalSpy sourceDataChangeSpy(model, &QAbstractItemModel::dataChanged);
+    QVERIFY(sourceDataChangeSpy.isValid());
+    QSignalSpy proxyDataChangeSpy(&proxy, &QAbstractItemModel::dataChanged);
+    QVERIFY(proxyDataChangeSpy.isValid());
+    const QMap<int, QVariant> itmData = {
+        std::make_pair<int, QVariant>(Qt::DisplayRole, QStringLiteral("Test")),
+        std::make_pair<int, QVariant>(Qt::UserRole, 88),
+        std::make_pair<int, QVariant>(Qt::UserRole + 1, 99),
+    };
+    QModelIndex idx = proxy.index(0, 1);
+    QVERIFY(proxy.setItemData(idx, itmData));
+    QCOMPARE(idx.data(Qt::DisplayRole).toString(), QStringLiteral("Test"));
+    QCOMPARE(idx.data(Qt::UserRole).toInt(), 88);
+    QCOMPARE(idx.data(Qt::UserRole + 1).toInt(), 99);
+    QCOMPARE(sourceDataChangeSpy.size(), 1);
+    QCOMPARE(proxyDataChangeSpy.size(), 1);
+    auto signalData = proxyDataChangeSpy.takeFirst();
+    QCOMPARE(signalData.at(0).value<QModelIndex>(), idx);
+    QCOMPARE(signalData.at(1).value<QModelIndex>(), idx);
+    const QVector<int> expectedRoles{Qt::DisplayRole, Qt::UserRole, Qt::EditRole, Qt::UserRole + 1};
+    QVector<int> receivedRoles = signalData.at(2).value<QVector<int> >();
+    QCOMPARE(receivedRoles.size(), expectedRoles.size());
+    for (int role : expectedRoles)
+        QVERIFY(receivedRoles.contains(role));
+    signalData = sourceDataChangeSpy.takeFirst();
+    QCOMPARE(signalData.at(0).value<QModelIndex>(), proxy.mapToSource(idx));
+    QCOMPARE(signalData.at(1).value<QModelIndex>(), proxy.mapToSource(idx));
+    receivedRoles = signalData.at(2).value<QVector<int> >();
+    QCOMPARE(receivedRoles.size(), expectedRoles.size());
+    for (int role : expectedRoles)
+        QVERIFY(receivedRoles.contains(role));
+    idx = proxy.index(1, 2, proxy.index(0, 1));
+    QVERIFY(proxy.setItemData(idx, itmData));
+    QCOMPARE(idx.data(Qt::DisplayRole).toString(), QStringLiteral("Test"));
+    QCOMPARE(idx.data(Qt::UserRole).toInt(), 88);
+    QCOMPARE(idx.data(Qt::UserRole + 1).toInt(), 99);
+    QCOMPARE(idx.data(Qt::UserRole + 2).toInt(), 2);
+    QCOMPARE(idx.data(Qt::UserRole + 3).toInt(), 1);
+    QCOMPARE(sourceDataChangeSpy.size(), 1);
+    QCOMPARE(proxyDataChangeSpy.size(), 1);
+    signalData = proxyDataChangeSpy.takeFirst();
+    QCOMPARE(signalData.at(0).value<QModelIndex>(), idx);
+    QCOMPARE(signalData.at(1).value<QModelIndex>(), idx);
+    receivedRoles = signalData.at(2).value<QVector<int> >();
+    QCOMPARE(receivedRoles.size(), expectedRoles.size());
+    for (int role : expectedRoles)
+        QVERIFY(receivedRoles.contains(role));
+    signalData = sourceDataChangeSpy.takeFirst();
+    QCOMPARE(signalData.at(0).value<QModelIndex>(), proxy.mapToSource(idx));
+    QCOMPARE(signalData.at(1).value<QModelIndex>(), proxy.mapToSource(idx));
+    receivedRoles = signalData.at(2).value<QVector<int> >();
+    QCOMPARE(receivedRoles.size(), expectedRoles.size());
+    for (int role : expectedRoles)
+        QVERIFY(receivedRoles.contains(role));
+    QVERIFY(!proxy.setItemData(QModelIndex(), itmData));
+    delete model;
+}
+
+void tst_QTransposeProxyModel::moveRowsBase()
+{
+    QStringListModel model{QStringList{"A", "B", "C", "D"}};
+    QTransposeProxyModel proxy;
+    QSignalSpy columnsMoveSpy(&proxy, &QAbstractItemModel::columnsMoved);
+    QVERIFY(columnsMoveSpy.isValid());
+    QSignalSpy columnsAboutToBeMoveSpy(&proxy, &QAbstractItemModel::columnsAboutToBeMoved);
+    QVERIFY(columnsAboutToBeMoveSpy.isValid());
+    new QAbstractItemModelTester(&proxy, &proxy);
+    proxy.setSourceModel(&model);
+    const QStringList expectedNewVal = {"B", "A", "C", "D"};
+    QVERIFY(model.moveRows(QModelIndex(), 0, 1, QModelIndex(), 2));
+    for (int i = 0; i < expectedNewVal.size(); ++i)
+        QCOMPARE(proxy.index(0, i).data(), expectedNewVal.at(i));
+    QCOMPARE(columnsMoveSpy.count(), 1);
+    QCOMPARE(columnsAboutToBeMoveSpy.count(), 1);
+    for (const auto &spyArgs : {columnsMoveSpy.takeFirst(),
+        columnsAboutToBeMoveSpy.takeFirst()}) {
+        QVERIFY(!spyArgs.at(0).value<QModelIndex>().isValid());
+        QCOMPARE(spyArgs.at(1).toInt(), 0);
+        QCOMPARE(spyArgs.at(2).toInt(), 0);
+        QVERIFY(!spyArgs.at(3).value<QModelIndex>().isValid());
+        QCOMPARE(spyArgs.at(4).toInt(), 2);
+    }
+}
+
+void tst_QTransposeProxyModel::moveColumnsProxy()
+{
+    QStringListModel model{QStringList{"A", "B", "C", "D"}};
+    QTransposeProxyModel proxy;
+    new QAbstractItemModelTester(&proxy, &proxy);
+    QSignalSpy columnsMoveSpy(&proxy, &QAbstractItemModel::columnsMoved);
+    QVERIFY(columnsMoveSpy.isValid());
+    QSignalSpy columnsAboutToBeMoveSpy(&proxy, &QAbstractItemModel::columnsAboutToBeMoved);
+    QVERIFY(columnsAboutToBeMoveSpy.isValid());
+    QSignalSpy rowsMoveSpy(&model, &QAbstractItemModel::rowsMoved);
+    QVERIFY(rowsMoveSpy.isValid());
+    QSignalSpy rowsAboutToBeMoveSpy(&model, &QAbstractItemModel::rowsAboutToBeMoved);
+    QVERIFY(rowsAboutToBeMoveSpy.isValid());
+    proxy.setSourceModel(&model);
+    const QStringList expectedNewVal = {"B", "A", "C", "D"};
+    QVERIFY(proxy.moveColumns(QModelIndex(), 0, 1, QModelIndex(), 2));
+    for (int i = 0; i < expectedNewVal.size(); ++i)
+        QCOMPARE(proxy.index(0, i).data(), expectedNewVal.at(i));
+    for (int i = 0; i < expectedNewVal.size(); ++i)
+        QCOMPARE(model.index(i, 0).data(), expectedNewVal.at(i));
+    QCOMPARE(columnsMoveSpy.count(), 1);
+    QCOMPARE(columnsAboutToBeMoveSpy.count(), 1);
+    QCOMPARE(rowsMoveSpy.count(), 1);
+    QCOMPARE(rowsAboutToBeMoveSpy.count(), 1);
+    for (const auto &spyArgs : {columnsMoveSpy.takeFirst(),
+        columnsAboutToBeMoveSpy.takeFirst(),
+        rowsMoveSpy.takeFirst(),rowsAboutToBeMoveSpy.takeFirst()}) {
+        QVERIFY(!spyArgs.at(0).value<QModelIndex>().isValid());
+        QCOMPARE(spyArgs.at(1).toInt(), 0);
+        QCOMPARE(spyArgs.at(2).toInt(), 0);
+        QVERIFY(!spyArgs.at(3).value<QModelIndex>().isValid());
+    }
+}
+
+void tst_QTransposeProxyModel::setData_data()
+{
+    QTest::addColumn<QAbstractItemModel *>("model");
+    QTest::addColumn<bool>("rootItem");
+    QTest::addColumn<bool>("viaProxy");
+    QTest::newRow("List_via_Base") << createListModel(this) << true << false;
+    QTest::newRow("Table_via_Base") << createTableModel(this) << true << false;
+    QTest::newRow("Tree_via_Base_Root_Item") << createTreeModel(this) << true << false;
+    QTest::newRow("Tree_via_Base_Child_Item") << createTreeModel(this) << false << false;
+    QTest::newRow("List_via_Proxy") << createListModel(this) << true << true;
+    QTest::newRow("Table_via_Proxy") << createTableModel(this) << true << true;
+    QTest::newRow("Tree_via_Proxy_Root_Item") << createTreeModel(this) << true << true;
+    QTest::newRow("Tree_via_Proxy_Child_Item") << createTreeModel(this) << false << true;
+}
+
+void tst_QTransposeProxyModel::setData()
+{
+    QFETCH(QAbstractItemModel *, model);
+    QFETCH(bool, rootItem);
+    QFETCH(bool, viaProxy);
+    QTransposeProxyModel proxy;
+    new QAbstractItemModelTester(&proxy, &proxy);
+    proxy.setSourceModel(model);
+    QSignalSpy sourceDataChangeSpy(model, &QAbstractItemModel::dataChanged);
+    QVERIFY(sourceDataChangeSpy.isValid());
+    QSignalSpy proxyDataChangeSpy(&proxy, &QAbstractItemModel::dataChanged);
+    QVERIFY(proxyDataChangeSpy.isValid());
+    const QString testData = QStringLiteral("TestingSetData");
+    if (viaProxy) {
+        const QModelIndex parIdx = rootItem ? QModelIndex() : proxy.index(0, 1);
+        QVERIFY(proxy.setData(proxy.index(0, 1, parIdx), testData));
+        QCOMPARE(model->index(1, 0, proxy.mapToSource(parIdx)).data().toString(), testData);
+    } else {
+        const QModelIndex parIdx = rootItem ? QModelIndex() : model->index(1, 0);
+        QVERIFY(model->setData(model->index(1, 0, parIdx), testData));
+        QCOMPARE(proxy.index(0, 1, proxy.mapFromSource(parIdx)).data().toString(), testData);
+    }
+    QCOMPARE(sourceDataChangeSpy.size(), 1);
+    QCOMPARE(proxyDataChangeSpy.size(), 1);
+    delete model;
+}
+
+QTEST_GUILESS_MAIN(tst_QTransposeProxyModel)
+
+#include "tst_qtransposeproxymodel.moc"