QTreeView - persistentEditor or delegates

[moti.lahiani]

Hi all
I have QTreeView implementation as QMyTreeView
to this tree i have contextMenu with action "rename"
when user choose rename the action call to my method

StartEditing(QModelIndex& indx) 
{
     this->openPersistentEditor(indx);
}

StartEditing(QModelIndex& indx) 
{
     this->openPersistentEditor(indx);
}

To copy to clipboard, switch view to plain text mode 

and i reimplemented the slot

currentChanged (QModelIndex& current, QModelIndex& previous)
{
    if(current!=previous)
    {
          //here i want to get the new text the user write before commitData
          this->closePersistentEditor(previous);
     }
}

currentChanged (QModelIndex& current, QModelIndex& previous)
{
    if(current!=previous)
    {
          //here i want to get the new text the user write before commitData
          this->closePersistentEditor(previous);
     }
}

To copy to clipboard, switch view to plain text mode 

what i need to do is to get the new text user enter and check it before commit it.
How can i do it? how can i get the text?
should i need to use delegate? how ? example will help?
thanks alot