org.eclipse.scada.hd.client

Interface Connection

All Superinterfaces:

Connection

public interface Connection
extends Connection

A client connection to the historical data server

Author:

Jens Reimann

Method Summary

Modifier and Type	Method and Description
void	addListListener(ItemListListener listener) Add a new listener to the connection in order to receive item list updates.
Query	createQuery(String itemId, QueryParameters parameters, QueryListener listener, boolean updateData) Create a new query on the server
void	removeListListener(ItemListListener listener) Remove a listener from the connection

Methods inherited from interface org.eclipse.scada.core.client.Connection

addConnectionStateListener, addPrivilegeListener, connect, connect, disconnect, dispose, getConnectionInformation, getPrivileges, getSessionProperties, getState, removeConnectionStateListener, removePrivilegeListener, setCallbackFactory

Method Detail

createQuery

Query createQuery(String itemId,
                  QueryParameters parameters,
                  QueryListener listener,
                  boolean updateData)

Create a new query on the server

Parameters:

itemId - the historical item to query

parameters - the initial query parameters

listener - the listener that will receive data

updateData - true if the query should provide continuous updates, false if the query should only be executed once an not data updates should be delivered after the query state changed to QueryState.COMPLETE.

Returns:

a new query instance, null is never returned

addListListener

void addListListener(ItemListListener listener)

Add a new listener to the connection in order to receive item list updates.

A new listener will also receive any already known items.

Parameters:

listener - the listener to add

removeListListener

void removeListListener(ItemListListener listener)

Remove a listener from the connection

Parameters:

listener - the listener to remove