Fix handling of changes to the root index of a VisualDataModel.

Store the root index as a QPersistentModelIndex so the index remains
valid as the model changes, and in the case the root index is
removed from the model invalidate the contents of the VisualDataModel
until a new root index or model is set.

Change-Id: I1cbc27f2068f99a02ff3d43373905dec7e35e900
Reviewed-by: Martin Jones <martin.jones@nokia.com>

1 files changed, 17 insertions, 0 deletions

diff --git a/src/quick/items/qquickvisualadaptormodel.cpp b/src/quick/items/qquickvisualadaptormodel.cpp
index b17ab26373..5076d84b81 100644
--- a/src/quick/items/qquickvisualadaptormodel.cpp
+++ b/src/quick/items/qquickvisualadaptormodel.cpp
@@ -459,6 +459,8 @@ public:
         if (aim && vdm) {
             QObject::disconnect(aim, SIGNAL(rowsInserted(QModelIndex,int,int)),
                                 vdm, SLOT(_q_rowsInserted(QModelIndex,int,int)));
+            QObject::disconnect(aim, SIGNAL(rowsAboutToBeRemoved(QModelIndex,int,int)),
+                                vdm, SLOT(_q_rowsAboutToBeRemoved(QModelIndex,int,int)));
             QObject::disconnect(aim, SIGNAL(rowsRemoved(QModelIndex,int,int)),
                                 vdm, SLOT(_q_rowsRemoved(QModelIndex,int,int)));
             QObject::disconnect(aim, SIGNAL(dataChanged(QModelIndex,QModelIndex,QVector<int>)),
@@ -898,6 +900,8 @@ void QQuickVisualAdaptorModel::setModel(const QVariant &variant, QQuickVisualDat
                               vdm, QQuickVisualDataModel, SLOT(_q_rowsInserted(QModelIndex,int,int)));
             qmlobject_connect(model, QAbstractItemModel, SIGNAL(rowsRemoved(QModelIndex,int,int)),
                               vdm,  QQuickVisualDataModel, SLOT(_q_rowsRemoved(QModelIndex,int,int)));
+            qmlobject_connect(model, QAbstractItemModel, SIGNAL(rowsAboutToBeRemoved(QModelIndex,int,int)),
+                              vdm,  QQuickVisualDataModel, SLOT(_q_rowsAboutToBeRemoved(QModelIndex,int,int)));
             qmlobject_connect(model, QAbstractItemModel, SIGNAL(dataChanged(QModelIndex,QModelIndex,QVector<int>)),
                               vdm, QQuickVisualDataModel, SLOT(_q_dataChanged(QModelIndex,QModelIndex,QVector<int>)));
             qmlobject_connect(model, QAbstractItemModel, SIGNAL(rowsMoved(QModelIndex,int,int,QModelIndex,int)),
@@ -922,6 +926,19 @@ void QQuickVisualAdaptorModel::setModel(const QVariant &variant, QQuickVisualDat
     }
 }
 
+void QQuickVisualAdaptorModel::invalidateModel(QQuickVisualDataModel *vdm)
+{
+    accessors->cleanup(*this, vdm);
+    accessors = &qt_vdm_null_accessors;
+    // Don't clear the model object as we still need the guard to clear the list variant if the
+    // object is destroyed.
+}
+
+bool QQuickVisualAdaptorModel::isValid() const
+{
+    return accessors != &qt_vdm_null_accessors;
+}
+
 void QQuickVisualAdaptorModel::objectDestroyed(QObject *)
 {
     setModel(QVariant(), 0, 0);