Use iterator instead of foreach

Using QMutableListIterator instead of foreach loop, which is more efficient
and safer, especially since items might be removed during iteration.

Renamed variable treeItem to childItemObject.

Libs/XNAT/Core/ctkXnatTreeModel.cpp

@@ -246,7 +246,6 @@ void ctkXnatTreeModel::refresh(const QModelIndex& parent)
     // Force a fetch for current object (it might has changed on the server)
     xnatObject->fetch(true);
 
-    QList<ctkXnatObject*> children = xnatObject->children();
     int numChildren = rowCount(parent);
 
     bool addToTreeView (true);
@@ -255,28 +254,33 @@ void ctkXnatTreeModel::refresh(const QModelIndex& parent)
     // if not -> add them
     // For all items of the treeview, check if they are still on the server
     // if not -> remove them
-    foreach (ctkXnatObject* child, children)
+    QList<ctkXnatObject*> children = xnatObject->children();
+    QMutableListIterator<ctkXnatObject*> iter (children);
+
+    while (iter.hasNext())
     {
+      ctkXnatObject* child = iter.next();
       for (int i = 0; i < numChildren; ++i)
       {
-        ctkXnatObject* treeItem = item->child(i)->xnatObject();
+        ctkXnatObject* childItemObject = item->child(i)->xnatObject();
 
         // If the item was deleted from the server in the meantime
         // -> remove it from the treeview
-        if (!treeItem->exists())
+        if (!childItemObject->exists())
         {
           beginRemoveRows(parent, item->child(i)->row(), item->child(i)->row());
-          item->remove(treeItem);
+          item->remove(childItemObject);
           xnatObject->remove(child);
-          children.removeOne(child);
+          iter.remove();
           endRemoveRows();
           --numChildren;
+          --i;
           addToTreeView = false;
           break;
         }
 
-        if ((treeItem->id().length() != 0 && treeItem->id() == child->id()) ||
-            (treeItem->id().length() == 0 && treeItem->name() == child->name()))
+        if ((childItemObject->id().length() != 0 && childItemObject->id() == child->id()) ||
+            (childItemObject->id().length() == 0 && childItemObject->name() == child->name()))
         {
           addToTreeView = false;
           break;
@@ -295,6 +299,7 @@ void ctkXnatTreeModel::refresh(const QModelIndex& parent)
       addToTreeView = true;
     }
 
+    numChildren = rowCount(parent);
     for (int i=0; i<numChildren; i++)
     {
       refresh(index(i,0,parent));