int changeType = listChanges.getType();
switch (changeType) {
case ListEvent.DELETE:
changeList.getReadWriteLock().readLock().lock();
TaskData t1 = (TaskData) listChanges.getOldValue();
changeList.getReadWriteLock().readLock().unlock();
t1.removePropertyChangeListener(this);
saveList();
break;
case ListEvent.INSERT:
changeList.getReadWriteLock().readLock().lock();
TaskData t2 = (TaskData) changeList.get(sourceIndex);
changeList.getReadWriteLock().readLock().unlock();
t2.addPropertyChangeListener(this);
saveList();
break;
case ListEvent.UPDATE:
break;