New proxy model: QConcatenateTablesProxyModel

It takes multiple source models and concatenates their rows into a single model.

With full unit tests.

[ChangeLog][QtCore] New class QConcatenateTablesProxyModel, to
concatenate the rows from multiple source models.

Change-Id: Iaf4f325473adef106f423677fdc5ee0e35e87d35
Reviewed-by: Luca Beldi <v.ronin@yahoo.it>
Reviewed-by: Sérgio Martins <sergio.martins@kdab.com>

3 files changed, 829 insertions, 0 deletions

diff --git a/tests/auto/corelib/itemmodels/itemmodels.pro b/tests/auto/corelib/itemmodels/itemmodels.pro
index bcb6e604f8..0346341be6 100644
--- a/tests/auto/corelib/itemmodels/itemmodels.pro
+++ b/tests/auto/corelib/itemmodels/itemmodels.pro
@@ -5,6 +5,7 @@ SUBDIRS = qabstractitemmodel \
 
 qtHaveModule(gui): SUBDIRS += \
     qabstractproxymodel \
+    qconcatenatetablesproxymodel \
     qidentityproxymodel \
     qitemselectionmodel \
     qsortfilterproxymodel_recursive \
diff --git a/tests/auto/corelib/itemmodels/qconcatenatetablesproxymodel/qconcatenatetablesproxymodel.pro b/tests/auto/corelib/itemmodels/qconcatenatetablesproxymodel/qconcatenatetablesproxymodel.pro
new file mode 100644
index 0000000000..ee4ea28b5b
--- /dev/null
+++ b/tests/auto/corelib/itemmodels/qconcatenatetablesproxymodel/qconcatenatetablesproxymodel.pro
@@ -0,0 +1,5 @@
+CONFIG += testcase
+TARGET = tst_qconcatenatetablesproxymodel
+QT = core gui testlib
+
+SOURCES = tst_qconcatenatetablesproxymodel.cpp
diff --git a/tests/auto/corelib/itemmodels/qconcatenatetablesproxymodel/tst_qconcatenatetablesproxymodel.cpp b/tests/auto/corelib/itemmodels/qconcatenatetablesproxymodel/tst_qconcatenatetablesproxymodel.cpp
new file mode 100644
index 0000000000..40617c1f7d
--- /dev/null
+++ b/tests/auto/corelib/itemmodels/qconcatenatetablesproxymodel/tst_qconcatenatetablesproxymodel.cpp
@@ -0,0 +1,823 @@
+/****************************************************************************
+**
+** Copyright (C) 2016 Klarälvdalens Datakonsult AB, a KDAB Group company, info@kdab.com, author David Faure <david.faure@kdab.com>
+** 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 <QSignalSpy>
+#include <QSortFilterProxyModel>
+#include <QTest>
+#include <QStandardItemModel>
+#include <QIdentityProxyModel>
+#include <QItemSelectionModel>
+#include <QMimeData>
+#include <QStringListModel>
+#include <QAbstractItemModelTester>
+
+#include <qconcatenatetablesproxymodel.h>
+
+Q_DECLARE_METATYPE(QModelIndex)
+
+// Extracts a full row from a model as a string
+// Works best if every cell contains only one character
+static QString extractRowTexts(QAbstractItemModel *model, int row, const QModelIndex &parent = QModelIndex())
+{
+    QString result;
+    const int colCount = model->columnCount();
+    for (int col = 0; col < colCount; ++col) {
+        const QString txt = model->index(row, col, parent).data().toString();
+        result += txt.isEmpty() ? QStringLiteral(" ") : txt;
+    }
+    return result;
+}
+
+// Extracts a full column from a model as a string
+// Works best if every cell contains only one character
+static QString extractColumnTexts(QAbstractItemModel *model, int column, const QModelIndex &parent = QModelIndex())
+{
+    QString result;
+    const int rowCount = model->rowCount();
+    for (int row = 0; row < rowCount; ++row) {
+        const QString txt = model->index(row, column, parent).data().toString();
+        result += txt.isEmpty() ? QStringLiteral(" ") : txt;
+    }
+    return result;
+}
+
+static QString rowSpyToText(const QSignalSpy &spy)
+{
+    if (!spy.isValid())
+        return QStringLiteral("THE SIGNALSPY IS INVALID!");
+    QString str;
+    for (int i = 0; i < spy.count(); ++i) {
+        str += spy.at(i).at(1).toString() + QLatin1Char(',') + spy.at(i).at(2).toString();
+        if (i + 1 < spy.count())
+            str += QLatin1Char(';');
+    }
+    return str;
+}
+
+class tst_QConcatenateTablesProxyModel : public QObject
+{
+    Q_OBJECT
+
+private Q_SLOTS:
+    void init();
+    void shouldAggregateTwoModelsCorrectly();
+    void shouldAggregateThenRemoveTwoEmptyModelsCorrectly();
+    void shouldAggregateTwoEmptyModelsWhichThenGetFilled();
+    void shouldHandleDataChanged();
+    void shouldHandleSetData();
+    void shouldHandleSetItemData();
+    void shouldHandleRowInsertionAndRemoval();
+    void shouldAggregateAnotherModelThenRemoveModels();
+    void shouldUseSmallestColumnCount();
+    void shouldIncreaseColumnCountWhenRemovingFirstModel();
+    void shouldHandleColumnInsertionAndRemoval();
+    void shouldPropagateLayoutChanged();
+    void shouldReactToModelReset();
+    void shouldUpdateColumnsOnModelReset();
+    void shouldPropagateDropOnItem_data();
+    void shouldPropagateDropOnItem();
+    void shouldPropagateDropBetweenItems();
+    void shouldPropagateDropBetweenItemsAtModelBoundary();
+    void shouldPropagateDropAfterLastRow_data();
+    void shouldPropagateDropAfterLastRow();
+
+private:
+    QStandardItemModel mod;
+    QStandardItemModel mod2;
+    QStandardItemModel mod3;
+};
+
+void tst_QConcatenateTablesProxyModel::init()
+{
+    // Prepare some source models to use later on
+    mod.clear();
+    mod.appendRow({ new QStandardItem(QStringLiteral("A")), new QStandardItem(QStringLiteral("B")), new QStandardItem(QStringLiteral("C")) });
+    mod.setHorizontalHeaderLabels(QStringList() << QStringLiteral("H1") << QStringLiteral("H2") << QStringLiteral("H3"));
+    mod.setVerticalHeaderLabels(QStringList() << QStringLiteral("One"));
+
+    mod2.clear();
+    mod2.appendRow({ new QStandardItem(QStringLiteral("D")), new QStandardItem(QStringLiteral("E")), new QStandardItem(QStringLiteral("F")) });
+    mod2.setHorizontalHeaderLabels(QStringList() << QStringLiteral("H1") << QStringLiteral("H2") << QStringLiteral("H3"));
+    mod2.setVerticalHeaderLabels(QStringList() << QStringLiteral("Two"));
+
+    mod3.clear();
+    mod3.appendRow({ new QStandardItem(QStringLiteral("1")), new QStandardItem(QStringLiteral("2")), new QStandardItem(QStringLiteral("3")) });
+    mod3.appendRow({ new QStandardItem(QStringLiteral("4")), new QStandardItem(QStringLiteral("5")), new QStandardItem(QStringLiteral("6")) });
+}
+
+void tst_QConcatenateTablesProxyModel::shouldAggregateTwoModelsCorrectly()
+{
+    // Given a combining proxy
+    QConcatenateTablesProxyModel pm;
+
+    // When adding two source models
+    pm.addSourceModel(&mod);
+    pm.addSourceModel(&mod2);
+    QAbstractItemModelTester modelTest(&pm, this);
+
+    // Then the proxy should show 2 rows
+    QCOMPARE(pm.rowCount(), 2);
+    QCOMPARE(extractRowTexts(&pm, 0), QStringLiteral("ABC"));
+    QCOMPARE(extractRowTexts(&pm, 1), QStringLiteral("DEF"));
+
+    // ... and correct headers
+    QCOMPARE(pm.headerData(0, Qt::Horizontal).toString(), QStringLiteral("H1"));
+    QCOMPARE(pm.headerData(1, Qt::Horizontal).toString(), QStringLiteral("H2"));
+    QCOMPARE(pm.headerData(2, Qt::Horizontal).toString(), QStringLiteral("H3"));
+    QCOMPARE(pm.headerData(0, Qt::Vertical).toString(), QStringLiteral("One"));
+    QCOMPARE(pm.headerData(1, Qt::Vertical).toString(), QStringLiteral("Two"));
+
+    QVERIFY(!pm.canFetchMore(QModelIndex()));
+}
+
+void tst_QConcatenateTablesProxyModel::shouldAggregateThenRemoveTwoEmptyModelsCorrectly()
+{
+    // Given a combining proxy
+    QConcatenateTablesProxyModel pm;
+
+    // When adding two empty models
+    QSignalSpy rowATBISpy(&pm, SIGNAL(rowsAboutToBeInserted(QModelIndex,int,int)));
+    QSignalSpy rowInsertedSpy(&pm, SIGNAL(rowsInserted(QModelIndex,int,int)));
+    QSignalSpy rowATBRSpy(&pm, SIGNAL(rowsAboutToBeRemoved(QModelIndex,int,int)));
+    QSignalSpy rowRemovedSpy(&pm, SIGNAL(rowsRemoved(QModelIndex,int,int)));
+    QIdentityProxyModel i1, i2;
+    pm.addSourceModel(&i1);
+    pm.addSourceModel(&i2);
+
+    // Then the proxy should still be empty (and no signals emitted)
+    QCOMPARE(pm.rowCount(), 0);
+    QCOMPARE(pm.columnCount(), 0);
+    QCOMPARE(rowATBISpy.count(), 0);
+    QCOMPARE(rowInsertedSpy.count(), 0);
+
+    // When removing the empty models
+    pm.removeSourceModel(&i1);
+    pm.removeSourceModel(&i2);
+
+    // Then the proxy should still be empty (and no signals emitted)
+    QCOMPARE(pm.rowCount(), 0);
+    QCOMPARE(pm.columnCount(), 0);
+    QCOMPARE(rowATBRSpy.count(), 0);
+    QCOMPARE(rowRemovedSpy.count(), 0);
+}
+
+void tst_QConcatenateTablesProxyModel::shouldAggregateTwoEmptyModelsWhichThenGetFilled()
+{
+    // Given a combining proxy with two empty models
+    QConcatenateTablesProxyModel pm;
+    QIdentityProxyModel i1, i2;
+    pm.addSourceModel(&i1);
+    pm.addSourceModel(&i2);
+
+    // When filling them afterwards
+    i1.setSourceModel(&mod);
+    i2.setSourceModel(&mod2);
+    QAbstractItemModelTester modelTest(&pm, this);
+
+    // Then the proxy should show 2 rows
+    QCOMPARE(pm.rowCount(), 2);
+    QCOMPARE(pm.columnCount(), 3);
+    QCOMPARE(extractRowTexts(&pm, 0), QStringLiteral("ABC"));
+    QCOMPARE(extractRowTexts(&pm, 1), QStringLiteral("DEF"));
+
+    // ... and correct headers
+    QCOMPARE(pm.headerData(0, Qt::Horizontal).toString(), QStringLiteral("H1"));
+    QCOMPARE(pm.headerData(1, Qt::Horizontal).toString(), QStringLiteral("H2"));
+    QCOMPARE(pm.headerData(2, Qt::Horizontal).toString(), QStringLiteral("H3"));
+    QCOMPARE(pm.headerData(0, Qt::Vertical).toString(), QStringLiteral("One"));
+    QCOMPARE(pm.headerData(1, Qt::Vertical).toString(), QStringLiteral("Two"));
+
+    QVERIFY(!pm.canFetchMore(QModelIndex()));
+}
+
+void tst_QConcatenateTablesProxyModel::shouldHandleDataChanged()
+{
+    // Given two models combined
+    QConcatenateTablesProxyModel pm;
+    pm.addSourceModel(&mod);
+    pm.addSourceModel(&mod2);
+    QAbstractItemModelTester modelTest(&pm, this);
+    QSignalSpy dataChangedSpy(&pm, SIGNAL(dataChanged(QModelIndex,QModelIndex)));
+
+    // When a cell in a source model changes
+    mod.item(0, 0)->setData("a", Qt::EditRole);
+
+    // Then the change should be notified to the proxy
+    QCOMPARE(dataChangedSpy.count(), 1);
+    QCOMPARE(dataChangedSpy.at(0).at(0).toModelIndex(), pm.index(0, 0));
+    QCOMPARE(extractRowTexts(&pm, 0), QStringLiteral("aBC"));
+
+    // Same test with the other model
+    mod2.item(0, 2)->setData("f", Qt::EditRole);
+
+    QCOMPARE(dataChangedSpy.count(), 2);
+    QCOMPARE(dataChangedSpy.at(1).at(0).toModelIndex(), pm.index(1, 2));
+    QCOMPARE(extractRowTexts(&pm, 1), QStringLiteral("DEf"));
+}
+
+void tst_QConcatenateTablesProxyModel::shouldHandleSetData()
+{
+    // Given two models combined
+    QConcatenateTablesProxyModel pm;
+    pm.addSourceModel(&mod);
+    pm.addSourceModel(&mod2);
+    QAbstractItemModelTester modelTest(&pm, this);
+    QSignalSpy dataChangedSpy(&pm, SIGNAL(dataChanged(QModelIndex,QModelIndex)));
+
+    // When changing a cell using setData
+    pm.setData(pm.index(0, 0), "a");
+
+    // Then the change should be notified to the proxy
+    QCOMPARE(dataChangedSpy.count(), 1);
+    QCOMPARE(dataChangedSpy.at(0).at(0).toModelIndex(), pm.index(0, 0));
+    QCOMPARE(extractRowTexts(&pm, 0), QStringLiteral("aBC"));
+
+    // Same test with the other model
+    pm.setData(pm.index(1, 2), "f");
+
+    QCOMPARE(dataChangedSpy.count(), 2);
+    QCOMPARE(dataChangedSpy.at(1).at(0).toModelIndex(), pm.index(1, 2));
+    QCOMPARE(extractRowTexts(&pm, 1), QStringLiteral("DEf"));
+}
+
+void tst_QConcatenateTablesProxyModel::shouldHandleSetItemData()
+{
+    // Given two models combined
+    QConcatenateTablesProxyModel pm;
+    pm.addSourceModel(&mod);
+    pm.addSourceModel(&mod2);
+    QAbstractItemModelTester modelTest(&pm, this);
+    QSignalSpy dataChangedSpy(&pm, SIGNAL(dataChanged(QModelIndex,QModelIndex)));
+
+    // When changing a cell using setData
+    pm.setItemData(pm.index(0, 0), QMap<int, QVariant>{ std::make_pair<int, QVariant>(Qt::DisplayRole, QStringLiteral("X")),
+                                                        std::make_pair<int, QVariant>(Qt::UserRole, 88) });
+
+    // Then the change should be notified to the proxy
+    QCOMPARE(dataChangedSpy.count(), 1);
+    QCOMPARE(dataChangedSpy.at(0).at(0).toModelIndex(), pm.index(0, 0));
+    QCOMPARE(extractRowTexts(&pm, 0), QStringLiteral("XBC"));
+    QCOMPARE(pm.index(0, 0).data(Qt::UserRole).toInt(), 88);
+
+    // Same test with the other model
+    pm.setItemData(pm.index(1, 2), QMap<int, QVariant>{ std::make_pair<int, QVariant>(Qt::DisplayRole, QStringLiteral("Y")),
+                                                        std::make_pair<int, QVariant>(Qt::UserRole, 89) });
+
+    QCOMPARE(dataChangedSpy.count(), 2);
+    QCOMPARE(dataChangedSpy.at(1).at(0).toModelIndex(), pm.index(1, 2));
+    QCOMPARE(extractRowTexts(&pm, 1), QStringLiteral("DEY"));
+    QCOMPARE(pm.index(1, 2).data(Qt::UserRole).toInt(), 89);
+}
+
+void tst_QConcatenateTablesProxyModel::shouldHandleRowInsertionAndRemoval()
+{
+    // Given two models combined
+    QConcatenateTablesProxyModel pm;
+    pm.addSourceModel(&mod);
+    pm.addSourceModel(&mod2);
+    QAbstractItemModelTester modelTest(&pm, this);
+    QSignalSpy rowATBISpy(&pm, SIGNAL(rowsAboutToBeInserted(QModelIndex,int,int)));
+    QSignalSpy rowInsertedSpy(&pm, SIGNAL(rowsInserted(QModelIndex,int,int)));
+
+    // When a source model inserts a new row
+    QList<QStandardItem *> row;
+    row.append(new QStandardItem(QStringLiteral("1")));
+    row.append(new QStandardItem(QStringLiteral("2")));
+    row.append(new QStandardItem(QStringLiteral("3")));
+    mod2.insertRow(0, row);
+
+    // Then the proxy should notify its users and show changes
+    QCOMPARE(rowSpyToText(rowATBISpy), QStringLiteral("1,1"));
+    QCOMPARE(rowSpyToText(rowInsertedSpy), QStringLiteral("1,1"));
+    QCOMPARE(pm.rowCount(), 3);
+    QCOMPARE(extractRowTexts(&pm, 0), QStringLiteral("ABC"));
+    QCOMPARE(extractRowTexts(&pm, 1), QStringLiteral("123"));
+    QCOMPARE(extractRowTexts(&pm, 2), QStringLiteral("DEF"));
+
+    // When removing that row
+    QSignalSpy rowATBRSpy(&pm, SIGNAL(rowsAboutToBeRemoved(QModelIndex,int,int)));
+    QSignalSpy rowRemovedSpy(&pm, SIGNAL(rowsRemoved(QModelIndex,int,int)));
+    mod2.removeRow(0);
+
+    // Then the proxy should notify its users and show changes
+    QCOMPARE(rowATBRSpy.count(), 1);
+    QCOMPARE(rowATBRSpy.at(0).at(1).toInt(), 1);
+    QCOMPARE(rowATBRSpy.at(0).at(2).toInt(), 1);
+    QCOMPARE(rowRemovedSpy.count(), 1);
+    QCOMPARE(rowRemovedSpy.at(0).at(1).toInt(), 1);
+    QCOMPARE(rowRemovedSpy.at(0).at(2).toInt(), 1);
+    QCOMPARE(pm.rowCount(), 2);
+    QCOMPARE(extractRowTexts(&pm, 0), QStringLiteral("ABC"));
+    QCOMPARE(extractRowTexts(&pm, 1), QStringLiteral("DEF"));
+
+    // When removing the last row from mod2
+    rowATBRSpy.clear();
+    rowRemovedSpy.clear();
+    mod2.removeRow(0);
+
+    // Then the proxy should notify its users and show changes
+    QCOMPARE(rowATBRSpy.count(), 1);
+    QCOMPARE(rowATBRSpy.at(0).at(1).toInt(), 1);
+    QCOMPARE(rowATBRSpy.at(0).at(2).toInt(), 1);
+    QCOMPARE(rowRemovedSpy.count(), 1);
+    QCOMPARE(rowRemovedSpy.at(0).at(1).toInt(), 1);
+    QCOMPARE(rowRemovedSpy.at(0).at(2).toInt(), 1);
+    QCOMPARE(pm.rowCount(), 1);
+    QCOMPARE(extractRowTexts(&pm, 0), QStringLiteral("ABC"));
+}
+
+void tst_QConcatenateTablesProxyModel::shouldAggregateAnotherModelThenRemoveModels()
+{
+    // Given two models combined, and a third model
+    QConcatenateTablesProxyModel pm;
+    pm.addSourceModel(&mod);
+    pm.addSourceModel(&mod2);
+    QAbstractItemModelTester modelTest(&pm, this);
+
+    QSignalSpy rowATBISpy(&pm, SIGNAL(rowsAboutToBeInserted(QModelIndex,int,int)));
+    QSignalSpy rowInsertedSpy(&pm, SIGNAL(rowsInserted(QModelIndex,int,int)));
+
+    // When adding the new source model
+    pm.addSourceModel(&mod3);
+
+    // Then the proxy should notify its users about the two rows inserted
+    QCOMPARE(rowSpyToText(rowATBISpy), QStringLiteral("2,3"));
+    QCOMPARE(rowSpyToText(rowInsertedSpy), QStringLiteral("2,3"));
+    QCOMPARE(pm.rowCount(), 4);
+    QCOMPARE(extractRowTexts(&pm, 0), QStringLiteral("ABC"));
+    QCOMPARE(extractRowTexts(&pm, 1), QStringLiteral("DEF"));
+    QCOMPARE(extractRowTexts(&pm, 2), QStringLiteral("123"));
+    QCOMPARE(extractRowTexts(&pm, 3), QStringLiteral("456"));
+
+    // When removing that source model again
+    QSignalSpy rowATBRSpy(&pm, SIGNAL(rowsAboutToBeRemoved(QModelIndex,int,int)));
+    QSignalSpy rowRemovedSpy(&pm, SIGNAL(rowsRemoved(QModelIndex,int,int)));
+    pm.removeSourceModel(&mod3);
+
+    // Then the proxy should notify its users about the row removed
+    QCOMPARE(rowATBRSpy.count(), 1);
+    QCOMPARE(rowATBRSpy.at(0).at(1).toInt(), 2);
+    QCOMPARE(rowATBRSpy.at(0).at(2).toInt(), 3);
+    QCOMPARE(rowRemovedSpy.count(), 1);
+    QCOMPARE(rowRemovedSpy.at(0).at(1).toInt(), 2);
+    QCOMPARE(rowRemovedSpy.at(0).at(2).toInt(), 3);
+    QCOMPARE(pm.rowCount(), 2);
+    QCOMPARE(extractRowTexts(&pm, 0), QStringLiteral("ABC"));
+    QCOMPARE(extractRowTexts(&pm, 1), QStringLiteral("DEF"));
+
+    // When removing model 2
+    rowATBRSpy.clear();
+    rowRemovedSpy.clear();
+    pm.removeSourceModel(&mod2);
+    QCOMPARE(rowATBRSpy.count(), 1);
+    QCOMPARE(rowATBRSpy.at(0).at(1).toInt(), 1);
+    QCOMPARE(rowATBRSpy.at(0).at(2).toInt(), 1);
+    QCOMPARE(rowRemovedSpy.count(), 1);
+    QCOMPARE(rowRemovedSpy.at(0).at(1).toInt(), 1);
+    QCOMPARE(rowRemovedSpy.at(0).at(2).toInt(), 1);
+    QCOMPARE(pm.rowCount(), 1);
+    QCOMPARE(extractRowTexts(&pm, 0), QStringLiteral("ABC"));
+
+    // When removing model 1
+    rowATBRSpy.clear();
+    rowRemovedSpy.clear();
+    pm.removeSourceModel(&mod);
+    QCOMPARE(rowATBRSpy.count(), 1);
+    QCOMPARE(rowATBRSpy.at(0).at(1).toInt(), 0);
+    QCOMPARE(rowATBRSpy.at(0).at(2).toInt(), 0);
+    QCOMPARE(rowRemovedSpy.count(), 1);
+    QCOMPARE(rowRemovedSpy.at(0).at(1).toInt(), 0);
+    QCOMPARE(rowRemovedSpy.at(0).at(2).toInt(), 0);
+    QCOMPARE(pm.rowCount(), 0);
+}
+
+void tst_QConcatenateTablesProxyModel::shouldUseSmallestColumnCount()
+{
+    QConcatenateTablesProxyModel pm;
+    pm.addSourceModel(&mod);
+    pm.addSourceModel(&mod2);
+    mod2.setColumnCount(1);
+    pm.addSourceModel(&mod3);
+    QAbstractItemModelTester modelTest(&pm, this);
+
+    QCOMPARE(pm.rowCount(), 4);
+    QCOMPARE(pm.columnCount(), 1);
+    QCOMPARE(extractRowTexts(&pm, 0), QStringLiteral("A"));
+    QCOMPARE(extractRowTexts(&pm, 1), QStringLiteral("D"));
+    QCOMPARE(extractRowTexts(&pm, 2), QStringLiteral("1"));
+    QCOMPARE(extractRowTexts(&pm, 3), QStringLiteral("4"));
+
+    const QModelIndex indexA = pm.mapFromSource(mod.index(0, 0));
+    QVERIFY(indexA.isValid());
+    QCOMPARE(indexA, pm.index(0, 0));
+
+    const QModelIndex indexB = pm.mapFromSource(mod.index(0, 1));
+    QVERIFY(!indexB.isValid());
+
+    const QModelIndex indexD = pm.mapFromSource(mod2.index(0, 0));
+    QVERIFY(indexD.isValid());
+    QCOMPARE(indexD, pm.index(1, 0));
+}
+
+void tst_QConcatenateTablesProxyModel::shouldIncreaseColumnCountWhenRemovingFirstModel()
+{
+    // Given a model with 2 columns and one with 3 columns
+    QConcatenateTablesProxyModel pm;
+    pm.addSourceModel(&mod);
+    QAbstractItemModelTester modelTest(&pm, this);
+    mod.setColumnCount(2);
+    pm.addSourceModel(&mod2);
+    QCOMPARE(pm.rowCount(), 2);
+    QCOMPARE(pm.columnCount(), 2);
+
+    QSignalSpy colATBISpy(&pm, SIGNAL(columnsAboutToBeInserted(QModelIndex,int,int)));
+    QSignalSpy colInsertedSpy(&pm, SIGNAL(columnsInserted(QModelIndex,int,int)));
+    QSignalSpy rowATBRSpy(&pm, SIGNAL(rowsAboutToBeRemoved(QModelIndex,int,int)));
+    QSignalSpy rowRemovedSpy(&pm, SIGNAL(rowsRemoved(QModelIndex,int,int)));
+
+    // When removing the first source model
+    pm.removeSourceModel(&mod);
+
+    // Then the proxy should notify its users about the row removed, and the column added
+    QCOMPARE(pm.rowCount(), 1);
+    QCOMPARE(pm.columnCount(), 3);
+    QCOMPARE(rowSpyToText(rowATBRSpy), QStringLiteral("0,0"));
+    QCOMPARE(rowSpyToText(rowRemovedSpy), QStringLiteral("0,0"));
+    QCOMPARE(rowSpyToText(colATBISpy), QStringLiteral("2,2"));
+    QCOMPARE(rowSpyToText(colInsertedSpy), QStringLiteral("2,2"));
+    QCOMPARE(extractRowTexts(&pm, 0), QStringLiteral("DEF"));
+}
+
+void tst_QConcatenateTablesProxyModel::shouldHandleColumnInsertionAndRemoval()
+{
+    // Given two models combined, one with 2 columns and one with 3
+    QConcatenateTablesProxyModel pm;
+    pm.addSourceModel(&mod);
+    QAbstractItemModelTester modelTest(&pm, this);
+    mod.setColumnCount(2);
+    pm.addSourceModel(&mod2);
+    QSignalSpy colATBISpy(&pm, SIGNAL(columnsAboutToBeInserted(QModelIndex,int,int)));
+    QSignalSpy colInsertedSpy(&pm, SIGNAL(columnsInserted(QModelIndex,int,int)));
+    QSignalSpy colATBRSpy(&pm, SIGNAL(columnsAboutToBeRemoved(QModelIndex,int,int)));
+    QSignalSpy colRemovedSpy(&pm, SIGNAL(columnsRemoved(QModelIndex,int,int)));
+
+    // When the first source model inserts a new column
+    QCOMPARE(mod.columnCount(), 2);
+    mod.setColumnCount(3);
+
+    // Then the proxy should notify its users and show changes
+    QCOMPARE(rowSpyToText(colATBISpy), QStringLiteral("2,2"));
+    QCOMPARE(rowSpyToText(colInsertedSpy), QStringLiteral("2,2"));
+    QCOMPARE(pm.rowCount(), 2);
+    QCOMPARE(pm.columnCount(), 3);
+    QCOMPARE(extractRowTexts(&pm, 0), QStringLiteral("AB "));
+    QCOMPARE(extractRowTexts(&pm, 1), QStringLiteral("DEF"));
+
+    // And when removing two columns
+    mod.setColumnCount(1);
+
+    // Then the proxy should notify its users and show changes
+    QCOMPARE(rowSpyToText(colATBRSpy), QStringLiteral("1,2"));
+    QCOMPARE(rowSpyToText(colRemovedSpy), QStringLiteral("1,2"));
+    QCOMPARE(pm.rowCount(), 2);
+    QCOMPARE(pm.columnCount(), 1);
+    QCOMPARE(extractRowTexts(&pm, 0), QStringLiteral("A"));
+    QCOMPARE(extractRowTexts(&pm, 1), QStringLiteral("D"));
+}
+
+void tst_QConcatenateTablesProxyModel::shouldPropagateLayoutChanged()
+{
+    // Given two source models, the second one being a QSFPM
+    QConcatenateTablesProxyModel pm;
+    pm.addSourceModel(&mod);
+    QAbstractItemModelTester modelTest(&pm, this);
+
+    QSortFilterProxyModel qsfpm;
+    qsfpm.setSourceModel(&mod3);
+    pm.addSourceModel(&qsfpm);
+
+    QCOMPARE(extractRowTexts(&pm, 0), QStringLiteral("ABC"));
+    QCOMPARE(extractRowTexts(&pm, 1), QStringLiteral("123"));
+    QCOMPARE(extractRowTexts(&pm, 2), QStringLiteral("456"));
+
+    // And a selection (row 1)
+    QItemSelectionModel selection(&pm);
+    selection.select(pm.index(1, 0), QItemSelectionModel::Select | QItemSelectionModel::Rows);
+    const QModelIndexList lst = selection.selectedIndexes();
+    QCOMPARE(lst.count(), 3);
+    for (int col = 0; col < lst.count(); ++col) {
+        QCOMPARE(lst.at(col).row(), 1);
+        QCOMPARE(lst.at(col).column(), col);
+    }
+
+    QSignalSpy layoutATBCSpy(&pm, SIGNAL(layoutAboutToBeChanged()));
+    QSignalSpy layoutChangedSpy(&pm, SIGNAL(layoutChanged()));
+
+    // When changing the sorting in the QSFPM
+    qsfpm.sort(0, Qt::DescendingOrder);
+
+    // Then the proxy should emit the layoutChanged signals, and show re-sorted data
+    QCOMPARE(extractRowTexts(&pm, 0), QStringLiteral("ABC"));
+    QCOMPARE(extractRowTexts(&pm, 1), QStringLiteral("456"));
+    QCOMPARE(extractRowTexts(&pm, 2), QStringLiteral("123"));
+    QCOMPARE(layoutATBCSpy.count(), 1);
+    QCOMPARE(layoutChangedSpy.count(), 1);
+
+    // And the selection should be updated accordingly (it became row 2)
+    const QModelIndexList lstAfter = selection.selectedIndexes();
+    QCOMPARE(lstAfter.count(), 3);
+    for (int col = 0; col < lstAfter.count(); ++col) {
+        QCOMPARE(lstAfter.at(col).row(), 2);
+        QCOMPARE(lstAfter.at(col).column(), col);
+    }
+}
+
+void tst_QConcatenateTablesProxyModel::shouldReactToModelReset()
+{
+    // Given two source models, the second one being a QSFPM
+    QConcatenateTablesProxyModel pm;
+    pm.addSourceModel(&mod);
+    QAbstractItemModelTester modelTest(&pm, this);
+
+    QSortFilterProxyModel qsfpm;
+    qsfpm.setSourceModel(&mod3);
+    pm.addSourceModel(&qsfpm);
+
+    QCOMPARE(extractRowTexts(&pm, 0), QStringLiteral("ABC"));
+    QCOMPARE(extractRowTexts(&pm, 1), QStringLiteral("123"));
+    QCOMPARE(extractRowTexts(&pm, 2), QStringLiteral("456"));
+    QSignalSpy rowATBRSpy(&pm, SIGNAL(rowsAboutToBeRemoved(QModelIndex,int,int)));
+    QSignalSpy rowRemovedSpy(&pm, SIGNAL(rowsRemoved(QModelIndex,int,int)));
+    QSignalSpy rowATBISpy(&pm, SIGNAL(rowsAboutToBeInserted(QModelIndex,int,int)));
+    QSignalSpy rowInsertedSpy(&pm, SIGNAL(rowsInserted(QModelIndex,int,int)));
+    QSignalSpy colATBRSpy(&pm, SIGNAL(columnsAboutToBeRemoved(QModelIndex,int,int)));
+    QSignalSpy colRemovedSpy(&pm, SIGNAL(columnsRemoved(QModelIndex,int,int)));
+    QSignalSpy modelATBResetSpy(&pm, SIGNAL(modelAboutToBeReset()));
+    QSignalSpy modelResetSpy(&pm, SIGNAL(modelReset()));
+
+    // When changing the source model of the QSFPM
+    qsfpm.setSourceModel(&mod2);
+
+    // Then the proxy should emit the reset signals, and show the new data
+    QCOMPARE(extractRowTexts(&pm, 0), QStringLiteral("ABC"));
+    QCOMPARE(extractRowTexts(&pm, 1), QStringLiteral("DEF"));
+    QCOMPARE(rowATBRSpy.count(), 0);
+    QCOMPARE(rowRemovedSpy.count(), 0);
+    QCOMPARE(rowATBISpy.count(), 0);
+    QCOMPARE(rowInsertedSpy.count(), 0);
+    QCOMPARE(colATBRSpy.count(), 0);
+    QCOMPARE(colRemovedSpy.count(), 0);
+    QCOMPARE(modelATBResetSpy.count(), 1);
+    QCOMPARE(modelResetSpy.count(), 1);
+}
+
+void tst_QConcatenateTablesProxyModel::shouldUpdateColumnsOnModelReset()
+{
+    // Given two source models, the first one being a QSFPM
+    QConcatenateTablesProxyModel pm;
+
+    QSortFilterProxyModel qsfpm;
+    qsfpm.setSourceModel(&mod3);
+    pm.addSourceModel(&qsfpm);
+    pm.addSourceModel(&mod);
+    QAbstractItemModelTester modelTest(&pm, this);
+
+    QCOMPARE(extractRowTexts(&pm, 0), QStringLiteral("123"));
+    QCOMPARE(extractRowTexts(&pm, 1), QStringLiteral("456"));
+    QCOMPARE(extractRowTexts(&pm, 2), QStringLiteral("ABC"));
+
+    // ... and a model with only 2 columns
+    QStandardItemModel mod2Columns;
+    mod2Columns.appendRow({ new QStandardItem(QStringLiteral("W")), new QStandardItem(QStringLiteral("X")) });
+
+    QSignalSpy rowATBRSpy(&pm, SIGNAL(rowsAboutToBeRemoved(QModelIndex,int,int)));
+    QSignalSpy rowRemovedSpy(&pm, SIGNAL(rowsRemoved(QModelIndex,int,int)));
+    QSignalSpy rowATBISpy(&pm, SIGNAL(rowsAboutToBeInserted(QModelIndex,int,int)));
+    QSignalSpy rowInsertedSpy(&pm, SIGNAL(rowsInserted(QModelIndex,int,int)));
+    QSignalSpy colATBRSpy(&pm, SIGNAL(columnsAboutToBeRemoved(QModelIndex,int,int)));
+    QSignalSpy colRemovedSpy(&pm, SIGNAL(columnsRemoved(QModelIndex,int,int)));
+    QSignalSpy modelATBResetSpy(&pm, SIGNAL(modelAboutToBeReset()));
+    QSignalSpy modelResetSpy(&pm, SIGNAL(modelReset()));
+
+    // When changing the source model of the QSFPM
+    qsfpm.setSourceModel(&mod2Columns);
+
+    // Then the proxy should reset, and show the new data
+    QCOMPARE(modelATBResetSpy.count(), 1);
+    QCOMPARE(modelResetSpy.count(), 1);
+    QCOMPARE(rowATBRSpy.count(), 0);
+    QCOMPARE(rowRemovedSpy.count(), 0);
+    QCOMPARE(rowATBISpy.count(), 0);
+    QCOMPARE(rowInsertedSpy.count(), 0);
+    QCOMPARE(colATBRSpy.count(), 0);
+    QCOMPARE(colRemovedSpy.count(), 0);
+
+    QCOMPARE(pm.rowCount(), 2);
+    QCOMPARE(extractRowTexts(&pm, 0), QStringLiteral("WX"));
+    QCOMPARE(extractRowTexts(&pm, 1), QStringLiteral("AB"));
+}
+
+void tst_QConcatenateTablesProxyModel::shouldPropagateDropOnItem_data()
+{
+    QTest::addColumn<int>("sourceRow");
+    QTest::addColumn<int>("destRow");
+    QTest::addColumn<QString>("expectedResult");
+
+    QTest::newRow("0-3") << 0 << 3 << QStringLiteral("ABCA");
+    QTest::newRow("1-2") << 1 << 2 << QStringLiteral("ABBD");
+    QTest::newRow("2-1") << 2 << 1 << QStringLiteral("ACCD");
+    QTest::newRow("3-0") << 3 << 0 << QStringLiteral("DBCD");
+
+}
+
+void tst_QConcatenateTablesProxyModel::shouldPropagateDropOnItem()
+{
+    // Given two source models who handle drops
+
+    // Note: QStandardItemModel handles drop onto items by inserting child rows,
+    // which is good for QTreeView but not for QTableView or QConcatenateTablesProxyModel.
+    // So we use QStringListModel here instead.
+    QConcatenateTablesProxyModel pm;
+    QStringListModel model1({QStringLiteral("A"), QStringLiteral("B")});
+    QStringListModel model2({QStringLiteral("C"), QStringLiteral("D")});
+    pm.addSourceModel(&model1);
+    pm.addSourceModel(&model2);
+    QAbstractItemModelTester modelTest(&pm, this);
+    QCOMPARE(extractColumnTexts(&pm, 0), QStringLiteral("ABCD"));
+
+    // When dragging one item
+    QFETCH(int, sourceRow);
+    QMimeData* mimeData = pm.mimeData({pm.index(sourceRow, 0)});
+    QVERIFY(mimeData);
+
+    // and dropping onto another item
+    QFETCH(int, destRow);
+    QVERIFY(pm.canDropMimeData(mimeData, Qt::CopyAction, -1, -1, pm.index(destRow, 0)));
+    QVERIFY(pm.dropMimeData(mimeData, Qt::CopyAction, -1, -1, pm.index(destRow, 0)));
+    delete mimeData;
+
+    // Then the result should be as expected
+    QFETCH(QString, expectedResult);
+    QCOMPARE(extractColumnTexts(&pm, 0), expectedResult);
+}
+
+void tst_QConcatenateTablesProxyModel::shouldPropagateDropBetweenItems()
+{
+    // Given two models combined
+    QConcatenateTablesProxyModel pm;
+    pm.addSourceModel(&mod3);
+    pm.addSourceModel(&mod2);
+    QAbstractItemModelTester modelTest(&pm, this);
+    QCOMPARE(pm.rowCount(), 3);
+    QCOMPARE(extractRowTexts(&pm, 0), QStringLiteral("123"));
+    QCOMPARE(extractRowTexts(&pm, 1), QStringLiteral("456"));
+    QCOMPARE(extractRowTexts(&pm, 2), QStringLiteral("DEF"));
+
+    // When dragging the last row
+    QModelIndexList indexes;
+    indexes.reserve(pm.columnCount());
+    for (int col = 0; col < pm.columnCount(); ++col) {
+        indexes.append(pm.index(2, col));
+    }
+    QMimeData* mimeData = pm.mimeData(indexes);
+    QVERIFY(mimeData);
+
+    // and dropping it before row 1
+    const int destRow = 1;
+    QVERIFY(pm.canDropMimeData(mimeData, Qt::CopyAction, destRow, 0, QModelIndex()));
+    QVERIFY(pm.dropMimeData(mimeData, Qt::CopyAction, destRow, 0, QModelIndex()));
+    delete mimeData;
+
+    // Then a new row should be inserted
+    QCOMPARE(pm.rowCount(), 4);
+    QCOMPARE(extractRowTexts(&pm, 0), QStringLiteral("123"));
+    QCOMPARE(extractRowTexts(&pm, 1), QStringLiteral("DEF"));
+    QCOMPARE(extractRowTexts(&pm, 2), QStringLiteral("456"));
+    QCOMPARE(extractRowTexts(&pm, 3), QStringLiteral("DEF"));
+}
+
+void tst_QConcatenateTablesProxyModel::shouldPropagateDropBetweenItemsAtModelBoundary()
+{
+    // Given two models combined
+    QConcatenateTablesProxyModel pm;
+    pm.addSourceModel(&mod3);
+    pm.addSourceModel(&mod2);
+    QAbstractItemModelTester modelTest(&pm, this);
+    QCOMPARE(pm.rowCount(), 3);
+    QCOMPARE(extractRowTexts(&pm, 0), QStringLiteral("123"));
+    QCOMPARE(extractRowTexts(&pm, 1), QStringLiteral("456"));
+    QCOMPARE(extractRowTexts(&pm, 2), QStringLiteral("DEF"));
+
+    // When dragging the first row
+    QModelIndexList indexes;
+    indexes.reserve(pm.columnCount());
+    for (int col = 0; col < pm.columnCount(); ++col) {
+        indexes.append(pm.index(0, col));
+    }
+    QMimeData* mimeData = pm.mimeData(indexes);
+    QVERIFY(mimeData);
+
+    // and dropping it before row 2
+    const int destRow = 2;
+    QVERIFY(pm.canDropMimeData(mimeData, Qt::CopyAction, destRow, 0, QModelIndex()));
+    QVERIFY(pm.dropMimeData(mimeData, Qt::CopyAction, destRow, 0, QModelIndex()));
+    delete mimeData;
+
+    // Then a new row should be inserted
+    QCOMPARE(pm.rowCount(), 4);
+    QCOMPARE(extractRowTexts(&pm, 0), QStringLiteral("123"));
+    QCOMPARE(extractRowTexts(&pm, 1), QStringLiteral("456"));
+    QCOMPARE(extractRowTexts(&pm, 2), QStringLiteral("123"));
+    QCOMPARE(extractRowTexts(&pm, 3), QStringLiteral("DEF"));
+
+    // and it should be part of the second model
+    QCOMPARE(mod2.rowCount(), 2);
+}
+
+void tst_QConcatenateTablesProxyModel::shouldPropagateDropAfterLastRow_data()
+{
+    QTest::addColumn<int>("destRow");
+
+    // Dropping after the last row is documented to be done with destRow == -1.
+    QTest::newRow("-1") << -1;
+    // However, sometimes QTreeView calls dropMimeData with destRow == rowCount...
+    // Not sure if that's a bug or not, but let's support it in the model, just in case.
+    QTest::newRow("3") << 3;
+}
+
+void tst_QConcatenateTablesProxyModel::shouldPropagateDropAfterLastRow()
+{
+    QFETCH(int, destRow);
+
+    // Given two models combined
+    QConcatenateTablesProxyModel pm;
+    pm.addSourceModel(&mod3);
+    pm.addSourceModel(&mod2);
+    QAbstractItemModelTester modelTest(&pm, this);
+    QCOMPARE(pm.rowCount(), 3);
+    QCOMPARE(extractRowTexts(&pm, 0), QStringLiteral("123"));
+    QCOMPARE(extractRowTexts(&pm, 1), QStringLiteral("456"));
+    QCOMPARE(extractRowTexts(&pm, 2), QStringLiteral("DEF"));
+
+    // When dragging the second row
+    QModelIndexList indexes;
+    indexes.reserve(pm.columnCount());
+    for (int col = 0; col < pm.columnCount(); ++col) {
+        indexes.append(pm.index(1, col));
+    }
+    QMimeData* mimeData = pm.mimeData(indexes);
+    QVERIFY(mimeData);
+
+    // and dropping it after the last row
+    QVERIFY(pm.canDropMimeData(mimeData, Qt::CopyAction, destRow, 0, QModelIndex()));
+    QVERIFY(pm.dropMimeData(mimeData, Qt::CopyAction, destRow, 0, QModelIndex()));
+    delete mimeData;
+
+    // Then a new row should be inserted at the end
+    QCOMPARE(pm.rowCount(), 4);
+    QCOMPARE(extractRowTexts(&pm, 0), QStringLiteral("123"));
+    QCOMPARE(extractRowTexts(&pm, 1), QStringLiteral("456"));
+    QCOMPARE(extractRowTexts(&pm, 2), QStringLiteral("DEF"));
+    QCOMPARE(extractRowTexts(&pm, 3), QStringLiteral("456"));
+
+}
+
+QTEST_GUILESS_MAIN(tst_QConcatenateTablesProxyModel)
+
+#include "tst_qconcatenatetablesproxymodel.moc"