FolderListModel: pessimize change signals when the filter changes

FileInfoThread doesn't have separate signals for insertions, deletions
and updates, so QQuickFolderListModel shouldn't make an assumption
that if the list got bigger, an insertion was the only thing that
happened.

Task-number: QTBUG-36576
Change-Id: Ibb02d64e1645dd6df231d28a93e424aaad0effff
Reviewed-by: Alan Alpert <aalpert@blackberry.com>

1 files changed, 17 insertions, 24 deletions

diff --git a/src/imports/folderlistmodel/qquickfolderlistmodel.cpp b/src/imports/folderlistmodel/qquickfolderlistmodel.cpp
index 5ed38db3d7..5dc4332d69 100644
--- a/src/imports/folderlistmodel/qquickfolderlistmodel.cpp
+++ b/src/imports/folderlistmodel/qquickfolderlistmodel.cpp
@@ -158,35 +158,28 @@ void QQuickFolderListModelPrivate::_q_directoryUpdated(const QString &directory,
     Q_UNUSED(directory);
 
     QModelIndex parent;
-    if (data.size() > list.size()) {
-        //File(s) removed. Since I do not know how many
-        //or where I need to update the whole list from the first item.
-        data = list;
-        q->beginRemoveRows(parent, fromIndex, toIndex);
-        q->endRemoveRows();
-        if (list.size() > 0) {
-            q->beginInsertRows(parent, fromIndex, list.size()-1);
-            q->endInsertRows();
-        }
-        emit q->rowCountChanged();
-    } else if (data.size() < list.size()) {
-        //qDebug() << "File added. FromIndex: " << fromIndex << " toIndex: " << toIndex << " list size: " << list.size();
-        //File(s) added. Calculate how many and insert
-        //from the first changed one.
-        toIndex = fromIndex + (list.size() - data.size()-1);
-        q->beginInsertRows(parent, fromIndex, toIndex);
-        q->endInsertRows();
-        data = list;
-        emit q->rowCountChanged();
+    if (data.size() == list.size()) {
         QModelIndex modelIndexFrom = q->createIndex(fromIndex, 0);
         QModelIndex modelIndexTo = q->createIndex(toIndex, 0);
+        data = list;
         emit q->dataChanged(modelIndexFrom, modelIndexTo);
     } else {
-        //qDebug() << "File has been updated";
-        QModelIndex modelIndexFrom = q->createIndex(fromIndex, 0);
-        QModelIndex modelIndexTo = q->createIndex(toIndex, 0);
+        // File(s) inserted or removed. Since I do not know how many
+        // or where, I need to update the whole list from the first item.
+        // This is a little pessimistic, but optimizing it would require
+        // more information in the signal from FileInfoThread.
+        if (data.size() > 0) {
+            q->beginRemoveRows(parent, 0, data.size() - 1);
+            q->endRemoveRows();
+        }
         data = list;
-        emit q->dataChanged(modelIndexFrom, modelIndexTo);
+        if (list.size() > 0) {
+            if (toIndex > list.size() - 1)
+                toIndex = list.size() - 1;
+            q->beginInsertRows(parent, 0, data.size() - 1);
+            q->endInsertRows();
+        }
+        emit q->rowCountChanged();
     }
 }