TableView: connect to 'layoutChanged' signal from the model

Ensure we rebuild the table when the model emits 'layoutChanged'.

Fixes: QTBUG-71140
Change-Id: I70dac897830bf5a12ae6987920e388743fd358a1
Reviewed-by: Shawn Rutledge <shawn.rutledge@qt.io>

4 files changed, 62 insertions, 2 deletions

diff --git a/src/quick/items/qquicktableview.cpp b/src/quick/items/qquicktableview.cpp
index 68d55d98ea..44c16e2d7e 100644
--- a/src/quick/items/qquicktableview.cpp
+++ b/src/quick/items/qquicktableview.cpp
@@ -1664,6 +1664,7 @@ void QQuickTableViewPrivate::connectToModel()
         connect(aim, &QAbstractItemModel::columnsInserted, this, &QQuickTableViewPrivate::columnsInsertedCallback);
         connect(aim, &QAbstractItemModel::columnsRemoved, this, &QQuickTableViewPrivate::columnsRemovedCallback);
         connect(aim, &QAbstractItemModel::modelReset, this, &QQuickTableViewPrivate::modelResetCallback);
+        connect(aim, &QAbstractItemModel::layoutChanged, this, &QQuickTableViewPrivate::layoutChangedCallback);
     } else {
         QObjectPrivate::connect(model, &QQmlInstanceModel::modelUpdated, this, &QQuickTableViewPrivate::modelUpdated);
     }
@@ -1689,6 +1690,7 @@ void QQuickTableViewPrivate::disconnectFromModel()
         disconnect(aim, &QAbstractItemModel::columnsInserted, this, &QQuickTableViewPrivate::columnsInsertedCallback);
         disconnect(aim, &QAbstractItemModel::columnsRemoved, this, &QQuickTableViewPrivate::columnsRemovedCallback);
         disconnect(aim, &QAbstractItemModel::modelReset, this, &QQuickTableViewPrivate::modelResetCallback);
+        disconnect(aim, &QAbstractItemModel::layoutChanged, this, &QQuickTableViewPrivate::layoutChangedCallback);
     } else {
         QObjectPrivate::disconnect(model, &QQmlInstanceModel::modelUpdated, this, &QQuickTableViewPrivate::modelUpdated);
     }
@@ -1751,6 +1753,14 @@ void QQuickTableViewPrivate::columnsRemovedCallback(const QModelIndex &parent, i
     scheduleRebuildTable(RebuildOption::ViewportOnly);
 }
 
+void QQuickTableViewPrivate::layoutChangedCallback(const QList<QPersistentModelIndex> &parents, QAbstractItemModel::LayoutChangeHint hint)
+{
+    Q_UNUSED(parents);
+    Q_UNUSED(hint);
+
+    scheduleRebuildTable(RebuildOption::ViewportOnly);
+}
+
 void QQuickTableViewPrivate::modelResetCallback()
 {
     scheduleRebuildTable(RebuildOption::All);
diff --git a/src/quick/items/qquicktableview_p_p.h b/src/quick/items/qquicktableview_p_p.h
index a4f829addd..2ed04f8d29 100644
--- a/src/quick/items/qquicktableview_p_p.h
+++ b/src/quick/items/qquicktableview_p_p.h
@@ -356,6 +356,7 @@ public:
     void rowsRemovedCallback(const QModelIndex &parent, int begin, int end);
     void columnsInsertedCallback(const QModelIndex &parent, int begin, int end);
     void columnsRemovedCallback(const QModelIndex &parent, int begin, int end);
+    void layoutChangedCallback(const QList<QPersistentModelIndex> &parents, QAbstractItemModel::LayoutChangeHint hint);
     void modelResetCallback();
 
     void _q_componentFinalized();
diff --git a/tests/auto/quick/qquicktableview/testmodel.h b/tests/auto/quick/qquicktableview/testmodel.h
index b1bb7a41b8..50f434019e 100644
--- a/tests/auto/quick/qquicktableview/testmodel.h
+++ b/tests/auto/quick/qquicktableview/testmodel.h
@@ -68,14 +68,13 @@ public:
         return { {Qt::DisplayRole, "display"} };
     }
 
-    Q_INVOKABLE void setModelData(const QPoint &cell, const QSize &span, const QString &prefix)
+    Q_INVOKABLE void setModelData(const QPoint &cell, const QSize &span, const QString &string)
     {
         for (int c = 0; c < span.width(); ++c) {
             for (int r = 0; r < span.height(); ++r) {
                 const int changedRow = cell.y() + r;
                 const int changedColumn = cell.x() + c;
                 const int serializedIndex = changedRow + (changedColumn * m_rows);
-                const QString string = prefix + QStringLiteral("%1,%2").arg(changedColumn).arg(changedRow);
                 modelData.insert(serializedIndex, string);
             }
         }
@@ -129,6 +128,17 @@ public:
         return true;
     }
 
+    void swapRows(int row1, int row2)
+    {
+        layoutAboutToBeChanged();
+        Q_ASSERT(modelData.contains(row1));
+        Q_ASSERT(modelData.contains(row2));
+        const QString tmp = modelData[row1];
+        modelData[row1] = modelData[row2];
+        modelData[row2] = tmp;
+        layoutChanged();
+    }
+
     void clear() {
         beginResetModel();
         m_rows = 0;
diff --git a/tests/auto/quick/qquicktableview/tst_qquicktableview.cpp b/tests/auto/quick/qquicktableview/tst_qquicktableview.cpp
index 38789fd7bf..d475ef9c4d 100644
--- a/tests/auto/quick/qquicktableview/tst_qquicktableview.cpp
+++ b/tests/auto/quick/qquicktableview/tst_qquicktableview.cpp
@@ -141,6 +141,7 @@ private slots:
     void flickOvershoot();
     void checkRowColumnCount();
     void modelSignals();
+    void checkModelSignalsUpdateLayout();
     void dataChangedSignal();
     void checkThatPoolIsDrainedWhenReuseIsFalse();
     void checkIfDelegatesAreReused_data();
@@ -1472,6 +1473,44 @@ void tst_QQuickTableView::modelSignals()
     QCOMPARE(tableView->columns(), 1);
 }
 
+void tst_QQuickTableView::checkModelSignalsUpdateLayout()
+{
+    // Check that if the model rearranges rows and emit the
+    // 'layoutChanged' signal, TableView will be updated correctly.
+    LOAD_TABLEVIEW("plaintableview.qml");
+
+    TestModel model(0, 1);
+    tableView->setModel(QVariant::fromValue(&model));
+    WAIT_UNTIL_POLISHED;
+
+    QCOMPARE(tableView->rows(), 0);
+    QCOMPARE(tableView->columns(), 1);
+
+    QString modelRow1Text = QStringLiteral("firstRow");
+    QString modelRow2Text = QStringLiteral("secondRow");
+    model.insertRow(0);
+    model.insertRow(0);
+    model.setModelData(QPoint(0, 0), QSize(1, 1), modelRow1Text);
+    model.setModelData(QPoint(0, 1), QSize(1, 1), modelRow2Text);
+    WAIT_UNTIL_POLISHED;
+
+    QCOMPARE(tableView->rows(), 2);
+    QCOMPARE(tableView->columns(), 1);
+
+    QString delegate1text = tableViewPrivate->loadedTableItem(QPoint(0, 0))->item->property("modelDataBinding").toString();
+    QString delegate2text = tableViewPrivate->loadedTableItem(QPoint(0, 1))->item->property("modelDataBinding").toString();
+    QCOMPARE(delegate1text, modelRow1Text);
+    QCOMPARE(delegate2text, modelRow2Text);
+
+    model.swapRows(0, 1);
+    WAIT_UNTIL_POLISHED;
+
+    delegate1text = tableViewPrivate->loadedTableItem(QPoint(0, 0))->item->property("modelDataBinding").toString();
+    delegate2text = tableViewPrivate->loadedTableItem(QPoint(0, 1))->item->property("modelDataBinding").toString();
+    QCOMPARE(delegate1text, modelRow2Text);
+    QCOMPARE(delegate2text, modelRow1Text);
+}
+
 void tst_QQuickTableView::dataChangedSignal()
 {
     // Check that bindings to the model inside a delegate gets updated