com.mxgraph.sharing

Class mxSession

java.lang.Object

com.mxgraph.sharing.mxSession

All Implemented Interfaces:

mxSharedState.mxDiagramChangeListener

public class mxSession
extends Object
implements mxSharedState.mxDiagramChangeListener

Implements a session that may be attached to a shared diagram. The session contains a synchronized buffer which is used to hold the pending edits which are to be sent to a specific client. The update mechnism between the server and the client uses HTTP requests (polling). The request is kept on the server for an amount of time or wakes up / returns immediately if the buffer is no longer empty.

Field Summary

Fields

Modifier and Type	Field and Description
protected StringBuffer	buffer Holds the send buffer for this session.
static int	DEFAULT_TIMEOUT Default timeout is 10000 ms.
protected mxSharedState	diagram Reference to the shared diagram.
protected String	id Holds the session ID.
protected long	lastTimeMillis Holds the last active time millis.

Constructor Summary

Constructors

Constructor and Description
mxSession(String id, mxSharedState diagram) Constructs a new session with the given ID.

Method Summary

Methods

Modifier and Type	Method and Description
void	destroy() Destroys the session and removes its listener from the shared diagram.
void	diagramChanged(Object sender, String edits) Fires when the shared diagram was changed.
String	getId() Returns the session ID.
String	getInitialMessage() Returns an XML string that represents the current state of the session and the shared diagram.
long	inactiveTimeMillis() Returns the number of milliseconds this session has been inactive.
String	init() Initializes the session buffer and returns a string that represents the state of the session.
String	poll() Returns the changes received by other sessions for the shared diagram.
String	poll(long timeout) Returns the changes received by other sessions for the shared diagram.
void	receive(Node message) Posts the change represented by the given XML string to the shared diagram.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

DEFAULT_TIMEOUT

public static int DEFAULT_TIMEOUT

Default timeout is 10000 ms.

id

protected String id

Holds the session ID.

diagram

protected mxSharedState diagram

Reference to the shared diagram.

buffer

protected StringBuffer buffer

Holds the send buffer for this session.

lastTimeMillis

protected long lastTimeMillis

Holds the last active time millis.

Constructor Detail

mxSession

public mxSession(String id,
         mxSharedState diagram)

Constructs a new session with the given ID.

Parameters:

id - Specifies the session ID to be used.

diagram - Reference to the shared diagram.

Method Detail

getId

public String getId()

Returns the session ID.

init

public String init()

Initializes the session buffer and returns a string that represents the state of the session.

Returns:

Returns the initial state of the session.

getInitialMessage

public String getInitialMessage()

Returns an XML string that represents the current state of the session and the shared diagram. A globally unique ID is used as the session's namespace, which is used on the client side to prefix IDs of newly created cells.

receive

public void receive(Node message)

Posts the change represented by the given XML string to the shared diagram.

Parameters:

message - XML that represents the change.

poll

public String poll()
            throws InterruptedException

Returns the changes received by other sessions for the shared diagram. The method returns an empty XML node if no change was received within 10 seconds.

Returns:

Returns a string representing the changes to the shared diagram.

Throws:

InterruptedException

poll

public String poll(long timeout)
            throws InterruptedException

Returns the changes received by other sessions for the shared diagram. The method returns an empty XML node if no change was received within the given timeout.

Parameters:

timeout - Time in milliseconds to wait for changes.

Returns:

Returns a string representing the changes to the shared diagram.

Throws:

InterruptedException

diagramChanged

public void diagramChanged(Object sender,
                  String edits)

Description copied from interface: mxSharedState.mxDiagramChangeListener

Fires when the shared diagram was changed.

Specified by:

diagramChanged in interface mxSharedState.mxDiagramChangeListener

Parameters:

sender - Session where the change was received from.

edits - String that represents the edits.

inactiveTimeMillis

public long inactiveTimeMillis()

Returns the number of milliseconds this session has been inactive.

destroy

public void destroy()

Destroys the session and removes its listener from the shared diagram.