org.eclipse.rwt.lifecycle
Class UICallBack

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

public final class UICallBack

extends Object

A utility class that provides some static helper methods to perform commonly needed tasks with respect to background thread management.

Since:

1.0

Method Summary

static void	activate(String id) To allow automatic UI-updates by server side background threads activate the UICallBack mechanism.
static void	deactivate(String id) To allow automatic UI-updates by server side background threads activate the UICallBack mechanism.
static void	runNonUIThreadWithFakeContext(Display display, Runnable runnable) Sometimes a background thread needs to access values that are stored in the session object that started the thread.

Methods inherited from class java.lang.Object

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

Method Detail

runNonUIThreadWithFakeContext

public static void runNonUIThreadWithFakeContext(Display display,
                                                 Runnable runnable)

Sometimes a background thread needs to access values that are stored in the session object that started the thread. In particular these values may be stored in session singletons. Accessing these singletons directly from the background thread would fail. This method fakes the missing request context and allows the runnable code to access those singletons.

Parameters:

display - The display that is bound to the session that contains the data to which the current thread should get access.

runnable - The runnable that contains the critical code that needs to have access to a request context.

See Also:

SessionSingletonBase, org.eclipse.rwt.internal.service.ContextProvider

activate

public static void activate(String id)

To allow automatic UI-updates by server side background threads activate the UICallBack mechanism. Call this method before the start of a thread and deactivate(java.lang.String) at the end. Each activation needs a session unique identifier as a kind of reference pointer to be able to decide when all background threads are finished.

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

Parameters:

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

See Also:

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

deactivate

public static void deactivate(String id)

To allow automatic UI-updates by server side background threads activate the UICallBack mechanism. Call deactivate(java.lang.String) method before the start of a thread and deactivateUICallBack at the end. Each activation needs a session unique identifier as a kind of reference pointer to be able to decide when all background threads are finished.

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

Parameters:

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

See Also:

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