from _LongOpStatus import LongOpStatus

class CursorIterator(object):
    
    def __init__(self, db, cursor, msg=""):
        self._db = db
        self._cursor = cursor
        self._status = LongOpStatus(total_steps=cursor.get_length(), interval=10)
        #self._status = LongOpStatus(msg=msg)

    def __iter__(self):
        try:
            # Emit start signal
            self._db.emit('long-op-start', (self._status,))
            
            first = self._cursor.first()
            if first: 
                yield first
            
            next = self._cursor.next()
            while next:
                yield next
            
                # check for cancel
                #if self._status.should_cancel():
                #    raise GrampsDbUserCancel
            
                # emit heartbeat
                self._status.heartbeat()
                next = self._cursor.next()
            
            # emit stop signal
            self._status.end()
            self._cursor.close()
            raise StopIteration
        except:
            # Not allowed to use 'finally' because we 
            # yeild inside the try clause.
            self._cursor.close()
            self._status.end()
            raise