org.eclipse.rap.rwt.lifecycle
Class UICallBack

java.lang.Object
  org.eclipse.rap.rwt.lifecycle.UICallBack

Deprecated. This class will be removed in a future release. Use ServerPushSession instead to enable/disable server push.

@Deprecated
public final class UICallBack
extends java.lang.Object

A utility class that provides methods to perform tasks related to UI updates from background threads.

Since:

2.0

Method Summary

static void	activate(java.lang.String id) Deprecated. Use ServerPushSession.start() instead.
static void	deactivate(java.lang.String id) Deprecated. Use ServerPushSession.stop() instead.
static void	runNonUIThreadWithFakeContext(Display display, java.lang.Runnable runnable) Deprecated. Use UISession.exec(Runnable) instead. You can obtain a reference to the UI session for a display by RWT.getUISession(Display). Example: RWT.getUISession( display ).exec( runnable ).

Methods inherited from class java.lang.Object

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

Method Detail

runNonUIThreadWithFakeContext

@Deprecated
public static void runNonUIThreadWithFakeContext(Display display,
                                                            java.lang.Runnable runnable)

Deprecated. Use UISession.exec(Runnable) instead. You can obtain a reference to the UI session for a display by RWT.getUISession(Display). Example: RWT.getUISession( display ).exec( runnable ).

Executes a given runnable in the context of the UI session that is associated with the given display. This allows background threads to access values that are stored in the UI session, including session singletons.

Parameters:

display - the display that is bound to the UI session which the runnable needs to access

runnable - the runnable to execute in the UI session context of the given display

See Also:

SingletonUtil

activate

@Deprecated
public static void activate(java.lang.String id)

Deprecated. Use ServerPushSession.start() instead.

Call this method to enable UI updates from background threads (e.g. via Display.asyncExec()}. The UI callback must be activated from the UI thread before the background thread starts. Each activation is given a session-unique id to allow reference-counting activation and deactivation.

If not deactivated explicitly, any active UI callbacks are released when the session terminates.

Note: this method must only be called from the UI-Thread of an RWT application.

Example code:

 final String callbackId = "callback id";
 Runnable bgRunnable = new Runnable() {
   public void run() {
   // do some work...
   // schedule the UI update
   display.asyncExec( new Runnable() {
     public void run() {
       if( !widget.isDisposed() ) {
         // update the UI
       }
     }
   } );
   // Deactivate the UI call-back
   UICallBack.runNonUIThreadWithFakeContext( display, new Runnable() {
     public void run() {
       UICallBack.deactivate( callbackId );
     }
   } );
   }
 };
 UICallBack.activate( callbackId );
 Thread bgThread = new Thread( bgRunnable );
 bgThread.setDaemon( true );
 bgThread.start();
 

Parameters:

id - a session unique identifier to trace the activation and deactivation. Must not be null.

Throws:

SWTException -

• ERROR_NULL_ARGUMENT - if the id is null
• ERROR_THREAD_INVALID_ACCESS - if not called from the UI thread

See Also:

Display.syncExec(java.lang.Runnable), Display.asyncExec(java.lang.Runnable), Display.getThread(), Display.wake()

deactivate

@Deprecated
public static void deactivate(java.lang.String id)

Deprecated. Use ServerPushSession.stop() instead.

This method deactivates a previously activated UI callback with the same id. Calling this method with an id that wasn't activated before has no effect.

For each id, the system maintains a reference counter so that multiple activations of the same id must be followed by the same number deactivations in oder to actually stop the UI callback.

Note: this method must only be called from code that is associated with a session. That is, either code running in the UI thread or executed via runNonUIThreadWithFakeContext(Display, Runnable)

Parameters:

id - A session unique identifier to trace the activation and deactivation. Must not be null

Throws:

SWTException -

• ERROR_NULL_ARGUMENT - if the id is null
• ERROR_THREAD_INVALID_ACCESS - if not called from session code

See Also:

Display.syncExec(java.lang.Runnable), Display.asyncExec(java.lang.Runnable), Display.getThread(), Display.wake()