net.sf.mmm.client.ui.api

Interface UiDispatcher

All Known Implementing Classes:

AbstractUiDispatcher, UiDispatcherGwt, UiDispatcherTestImpl

public interface UiDispatcher

This is the interface for the dispatcher of UI events.

Since:

1.0.0

Author:

Joerg Hohwiller (hohwille at users.sourceforge.net)

See Also:

UiContext.getDispatcher()

Method Summary

Modifier and Type	Method and Description
boolean	dispatch() If you want to support SWT in its intended way (this method delegates to Display.readAndDispatch), you need to call this method frequently from a main loop of your application client.
void	invokeAsynchron(Runnable task) This method invokes the given task asynchronous in the dispatcher thread of the UI.
<T> T	invokeSynchron(Callable<T> task) This method invokes the given task synchronous in the dispatcher thread of the UI.
void	invokeSynchron(Runnable task) This method invokes the given task synchronous in the dispatcher thread of the UI.
void	invokeTimer(Callable<Boolean> task, int delayMilliseconds) This method invokes the given task periodically.
void	invokeTimer(Runnable task, int delayMilliseconds) This method invokes the given task asynchronous after the given dalay.
boolean	isDispatchThread() This method checks if the "current thread" is the dispatcher thread of the underlying UI toolkit.
boolean	sleep() This method puts the UI thread to sleep until a event to dispatch is received or it is awakened.

Method Detail

dispatch

boolean dispatch()

If you want to support SWT in its intended way (this method delegates to Display.readAndDispatch), you need to call this method frequently from a main loop of your application client. For other toolkit implementations this method will simply do nothing.
If you have a main loop in your foreground thread waiting until the GUI is closed, it is recommended to call this method from your main loop followed by sleep().

Returns:

true if there is more work to do, false if it is safe to sleep for a short while.

sleep

boolean sleep()

This method puts the UI thread to sleep until a event to dispatch is received or it is awakened.

Returns:

true if an event to dispatch was received, false otherwise.

isDispatchThread

boolean isDispatchThread()

This method checks if the "current thread" is the dispatcher thread of the underlying UI toolkit.

Returns:

true if this method was invoked within the dispatcher thread, false otherwise.

invokeSynchron

void invokeSynchron(Runnable task)

This method invokes the given task synchronous in the dispatcher thread of the UI. The term "synchronous" means that the current thread is suspended and this method will NOT return before the task is completed. If this method is called in the dispatcher thread or there is NO dispatcher thread in the underlying UI implementation, the task may simply be invoked directly in the implementation of this method.

Parameters:

task - is the job to invoke.

invokeAsynchron

void invokeAsynchron(Runnable task)

This method invokes the given task asynchronous in the dispatcher thread of the UI. The term "asynchronous" means that this method may return before the task is invoked. If there is NO dispatcher thread in the underlying UI implementation, the task may simply be invoked directly in the implementation of this method.

Parameters:

task - is the job to invoke.

invokeTimer

void invokeTimer(Runnable task,
                 int delayMilliseconds)

This method invokes the given task asynchronous after the given dalay.

Parameters:

task - is the job to invoke.

delayMilliseconds - is the delay in milliseconds when the task shall be executed.

invokeTimer

void invokeTimer(Callable<Boolean> task,
                 int delayMilliseconds)

This method invokes the given task periodically. The first invocation is performed after the given delay. Every time the task returns true, another invocation is performed after the same delay until false is returned.

Parameters:

task - is the job to invoke.

delayMilliseconds - is the periodically delay in milliseconds when the task shall be executed.

invokeSynchron

<T> T invokeSynchron(Callable<T> task)
              throws Exception

This method invokes the given task synchronous in the dispatcher thread of the UI. The term "synchronous" means that the current thread is suspended and this method will NOT return before the task is completed. If this method is called in the dispatcher thread or there is NO dispatcher thread in the underlying UI implementation, the task may simply be invoked directly in the implementation of this method.

Type Parameters:

T - is the templated type of the task result.

Parameters:

task - is the piece of code to be executed synchronous.

Returns:

is the result of the task.

Throws:

Exception - if Callable.call() throws an exception.