QQmlDelegateModel: Refresh the view when a column is added at 0

It can happen that a model reports n>0 rows but columns=0 (See
QConcatenateTablesProxyModel). In those cases we would render glitchy
items until the elements are marked as dirty.

Change-Id: I615c9cacbb1b6f9dee3898b03476605e5ac39d0a
Reviewed-by: Ulf Hermann <ulf.hermann@qt.io>
(cherry picked from commit ec9251efb918f37971aeefa1f687d137d037ff12)
Reviewed-by: Qt Cherry-pick Bot <cherrypick_bot@qt-project.org>

2 files changed, 47 insertions, 0 deletions

diff --git a/src/qmlmodels/qqmldelegatemodel.cpp b/src/qmlmodels/qqmldelegatemodel.cpp
index 5c5f464cd5..bbaad6d878 100644
--- a/src/qmlmodels/qqmldelegatemodel.cpp
+++ b/src/qmlmodels/qqmldelegatemodel.cpp
@@ -389,6 +389,12 @@ void QQmlDelegateModelPrivate::connectToAbstractItemModel()
                       q,  QQmlDelegateModel, SLOT(_q_rowsRemoved(QModelIndex,int,int)));
     qmlobject_connect(aim, QAbstractItemModel, SIGNAL(rowsAboutToBeRemoved(QModelIndex,int,int)),
                       q,  QQmlDelegateModel, SLOT(_q_rowsAboutToBeRemoved(QModelIndex,int,int)));
+    qmlobject_connect(aim, QAbstractItemModel, SIGNAL(columnsInserted(QModelIndex,int,int)),
+                      q, QQmlDelegateModel, SLOT(_q_columnsInserted(QModelIndex,int,int)));
+    qmlobject_connect(aim, QAbstractItemModel, SIGNAL(columnsRemoved(QModelIndex,int,int)),
+                      q, QQmlDelegateModel, SLOT(_q_columnsRemoved(QModelIndex,int,int)));
+    qmlobject_connect(aim, QAbstractItemModel, SIGNAL(columnsMoved(QModelIndex,int,int,QModelIndex,int)),
+                      q, QQmlDelegateModel, SLOT(_q_columnsMoved(QModelIndex,int,int,QModelIndex,int)));
     qmlobject_connect(aim, QAbstractItemModel, SIGNAL(dataChanged(QModelIndex,QModelIndex,QVector<int>)),
                       q, QQmlDelegateModel, SLOT(_q_dataChanged(QModelIndex,QModelIndex,QVector<int>)));
     qmlobject_connect(aim, QAbstractItemModel, SIGNAL(rowsMoved(QModelIndex,int,int,QModelIndex,int)),
@@ -413,6 +419,12 @@ void QQmlDelegateModelPrivate::disconnectFromAbstractItemModel()
                         q, SLOT(_q_rowsAboutToBeRemoved(QModelIndex,int,int)));
     QObject::disconnect(aim, SIGNAL(rowsRemoved(QModelIndex,int,int)),
                         q, SLOT(_q_rowsRemoved(QModelIndex,int,int)));
+    QObject::disconnect(aim, SIGNAL(columnsInserted(QModelIndex,int,int)), q,
+                        SLOT(_q_columnsInserted(QModelIndex,int,int)));
+    QObject::disconnect(aim, SIGNAL(columnsRemoved(QModelIndex,int,int)), q,
+                        SLOT(_q_columnsRemoved(QModelIndex,int,int)));
+    QObject::disconnect(aim, SIGNAL(columnsMoved(QModelIndex,int,int,QModelIndex,int)), q,
+                        SLOT(_q_columnsMoved(QModelIndex,int,int,QModelIndex,int)));
     QObject::disconnect(aim, SIGNAL(dataChanged(QModelIndex,QModelIndex,QVector<int>)),
                         q, SLOT(_q_dataChanged(QModelIndex,QModelIndex,QVector<int>)));
     QObject::disconnect(aim, SIGNAL(rowsMoved(QModelIndex,int,int,QModelIndex,int)),
@@ -1970,6 +1982,38 @@ void QQmlDelegateModel::_q_rowsMoved(
     }
 }
 
+void QQmlDelegateModel::_q_columnsInserted(const QModelIndex &parent, int begin, int end)
+{
+    Q_D(QQmlDelegateModel);
+    Q_UNUSED(end);
+    if (parent == d->m_adaptorModel.rootIndex && begin == 0) {
+        // mark all items as changed
+        _q_itemsChanged(0, d->m_count, QVector<int>());
+    }
+}
+
+void QQmlDelegateModel::_q_columnsRemoved(const QModelIndex &parent, int begin, int end)
+{
+    Q_D(QQmlDelegateModel);
+    Q_UNUSED(end);
+    if (parent == d->m_adaptorModel.rootIndex && begin == 0) {
+        // mark all items as changed
+        _q_itemsChanged(0, d->m_count, QVector<int>());
+    }
+}
+
+void QQmlDelegateModel::_q_columnsMoved(const QModelIndex &parent, int start, int end,
+                                        const QModelIndex &destination, int column)
+{
+    Q_D(QQmlDelegateModel);
+    Q_UNUSED(end);
+    if ((parent == d->m_adaptorModel.rootIndex && start == 0)
+        || (destination == d->m_adaptorModel.rootIndex && column == 0)) {
+        // mark all items as changed
+        _q_itemsChanged(0, d->m_count, QVector<int>());
+    }
+}
+
 void QQmlDelegateModel::_q_dataChanged(const QModelIndex &begin, const QModelIndex &end, const QVector<int> &roles)
 {
     Q_D(QQmlDelegateModel);
diff --git a/src/qmlmodels/qqmldelegatemodel_p.h b/src/qmlmodels/qqmldelegatemodel_p.h
index f4578e130e..2ce02c4aa5 100644
--- a/src/qmlmodels/qqmldelegatemodel_p.h
+++ b/src/qmlmodels/qqmldelegatemodel_p.h
@@ -152,6 +152,9 @@ private Q_SLOTS:
     void _q_itemsMoved(int from, int to, int count);
     void _q_modelReset();
     void _q_rowsInserted(const QModelIndex &,int,int);
+    void _q_columnsInserted(const QModelIndex &, int, int);
+    void _q_columnsRemoved(const QModelIndex &, int, int);
+    void _q_columnsMoved(const QModelIndex &, int, int, const QModelIndex &, int);
     void _q_rowsAboutToBeRemoved(const QModelIndex &parent, int begin, int end);
     void _q_rowsRemoved(const QModelIndex &,int,int);
     void _q_rowsMoved(const QModelIndex &, int, int, const QModelIndex &, int);