QQmlDelegateModel: even for QAIM, only use first column by default

In 2f9afadd5d9b4899397dca, we introduced a change in QQmlAdaptorModel
so that a QAIM model report that it contains "rows * cols" number of
model items, and not just "rows". This was needed, otherwise TableView
would only display the first column of such models.

It turns out, however, that also ListView will now detect that a
QAIM contain more items than just the items in the first column.
The result will be that it ends up adding all the other columns
underneath the first column in the view.

To avoid this unforseen change, this patch will revert this logic, and
instead add a private variable that can be set if the new behavior
is wanted (e.g by TableView).

Change-Id: I8c13da99f05e2f922362e498d1fa1779cdbd0d72
Reviewed-by: Mitch Curtis <mitch.curtis@qt.io>

2 files changed, 13 insertions, 4 deletions

diff --git a/src/qml/types/qqmldelegatemodel.cpp b/src/qml/types/qqmldelegatemodel.cpp
index 68bb185eaa..33fe5f3438 100644
--- a/src/qml/types/qqmldelegatemodel.cpp
+++ b/src/qml/types/qqmldelegatemodel.cpp
@@ -213,6 +213,7 @@ QQmlDelegateModelPrivate::QQmlDelegateModelPrivate(QQmlContext *ctxt)
     , m_transaction(false)
     , m_incubatorCleanupScheduled(false)
     , m_waitingToFetchMore(false)
+    , m_useFirstColumnOnly(true)
     , m_cacheItems(nullptr)
     , m_items(nullptr)
     , m_persistedItems(nullptr)
@@ -227,6 +228,11 @@ QQmlDelegateModelPrivate::~QQmlDelegateModelPrivate()
         m_cacheMetaType->release();
 }
 
+int QQmlDelegateModelPrivate::adaptorModelCount() const
+{
+    return m_useFirstColumnOnly ? m_adaptorModel.rowCount() : m_adaptorModel.count();
+}
+
 void QQmlDelegateModelPrivate::requestMoreIfNecessary()
 {
     Q_Q(QQmlDelegateModel);
@@ -336,7 +342,7 @@ void QQmlDelegateModel::componentComplete()
         static_cast<QQmlPartsModel *>(d->m_pendingParts.first())->updateFilterGroup();
 
     QVector<Compositor::Insert> inserts;
-    d->m_count = d->m_adaptorModel.count();
+    d->m_count = d->adaptorModelCount();
     d->m_compositor.append(
             &d->m_adaptorModel,
             0,
@@ -383,7 +389,7 @@ void QQmlDelegateModel::setModel(const QVariant &model)
     }
 
     if (d->m_complete) {
-        _q_itemsInserted(0, d->m_adaptorModel.count());
+        _q_itemsInserted(0, d->adaptorModelCount());
         d->requestMoreIfNecessary();
     }
 }
@@ -475,7 +481,7 @@ void QQmlDelegateModel::setRootIndex(const QVariant &root)
         if (d->m_adaptorModel.canFetchMore())
             d->m_adaptorModel.fetchMore();
         if (d->m_complete) {
-            const int newCount = d->m_adaptorModel.count();
+            const int newCount = d->adaptorModelCount();
             if (oldCount)
                 _q_itemsRemoved(0, oldCount);
             if (newCount)
@@ -1545,7 +1551,7 @@ void QQmlDelegateModel::_q_modelReset()
     d->m_adaptorModel.rootIndex = QModelIndex();
 
     if (d->m_complete) {
-        d->m_count = d->m_adaptorModel.count();
+        d->m_count = d->adaptorModelCount();
 
         const QList<QQmlDelegateModelItem *> cache = d->m_cache;
         for (int i = 0, c = cache.count();  i < c; ++i) {
diff --git a/src/qml/types/qqmldelegatemodel_p_p.h b/src/qml/types/qqmldelegatemodel_p_p.h
index d5f79fab62..a0c1f6aa12 100644
--- a/src/qml/types/qqmldelegatemodel_p_p.h
+++ b/src/qml/types/qqmldelegatemodel_p_p.h
@@ -302,6 +302,8 @@ public:
 
     bool insert(Compositor::insert_iterator &before, const QV4::Value &object, int groups);
 
+    int adaptorModelCount() const;
+
     static void group_append(QQmlListProperty<QQmlDelegateModelGroup> *property, QQmlDelegateModelGroup *group);
     static int group_count(QQmlListProperty<QQmlDelegateModelGroup> *property);
     static QQmlDelegateModelGroup *group_at(QQmlListProperty<QQmlDelegateModelGroup> *property, int index);
@@ -334,6 +336,7 @@ public:
     bool m_transaction : 1;
     bool m_incubatorCleanupScheduled : 1;
     bool m_waitingToFetchMore : 1;
+    bool m_useFirstColumnOnly : 1;
 
     union {
         struct {