I made a treeview with a model based on this example http://doc.qt.nokia.com/latest/itemv...treemodel.html And now I want to move items from one branch to another. Here's some of my code:

Qt Code: 
  1. QModelIndexList list = selectedIndexes();
  2.   RosterSortProxy *proxy = dynamic_cast<RosterSortProxy*>(model());
  3.   RosterItemModel *itemModel = dynamic_cast<RosterItemModel*>(proxy->sourceModel());
  4.  
  5.   QString group = action->property("group").toString();
  6.  
  7.   foreach(QModelIndex in, list) {
  8.     QModelIndex index = proxy->mapToSource(in);
  9.  
  10.     if(index.isValid()) {
  11.         RosterContact *cnt = static_cast<RosterContact*>(index.internalPointer());
  12.         if(cnt) {
  13.           itemModel->moveToGroup(cnt, group);
  14.         }
  15.       }
  16.   }
  17.  
  18.   proxy->invalidate();
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moveToGroup:
Qt Code: 
  1. RosterItem *newGroup = groupItem(groupName);
  2.   RosterItem *oldGroup = groupItem(item->contact()->group());
  3.  
  4.   if(newGroup != oldGroup) {
  5.     oldGroup->removeChild(item);
  6.     newGroup->appendChild(item);
  7.  
  8.     if((oldGroup->childCount() == 0) && (oldGroup != m_root)) {
  9.       removeGroup(oldGroup);
  10.     }
  11.   }
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removeChild and appendChild just remove/append the item to group's list of children.

And the problem I'm having is sometimes when I try to move a item, the program crashes, I tried to find a pattern for those crashes but couldn't. Also sometimes not all selected items are moved. I think it's an issue with the model not being updated, but I tried layoutAboutToBeChanged() and beginMoveRows() I even tried using both beginRemoveRows() and beginInsertRows() with no luck, I don't know if I'm using them wrong or what.

Please help.