com.jogamp.newt.util
Interface EDTUtil

public interface EDTUtil

EDT stands for Event Dispatch Thread.

EDTUtil comprises the functionality of:

• Periodically issuing an event dispatch command on the EDT.
• Ability to enqueue tasks, executed on the EDT.
• Controlling the EDT, ie start and stop in a sane manner.

The EDT pattern is a common tool to comply with todays windowing toolkits, where the common denominator in regards to multithreading is to:

• Create a Window on one thread
• Modify the Window within the same thread
• Handle incoming events from within the same thread

Note: This is not true on MacOSX, where all these actions have to be performed by a unique, so called main thread.

Field Summary

static long

defaultEDTPollPeriod

Method Summary

long	getPollPeriod()
boolean	invoke(boolean wait, Runnable task) Appends task to the EDT task queue if current thread is not EDT, otherwise execute task immediately.
boolean	invokeStop(boolean wait, Runnable finalTask) Append the final task to the EDT task queue, signals EDT to stop.
boolean	isCurrentThreadEDT() Returns true if the current thread is the event dispatch thread (EDT).
boolean	isCurrentThreadEDTorNEDT() Returns true if either isCurrentThreadEDT() or isCurrentThreadNEDT() is true, otherwise false.
boolean	isCurrentThreadNEDT() Returns true if the current thread is the internal NEWT event dequeue thread (NEDT).
boolean	isRunning()
void	setPollPeriod(long ms)
boolean	start() Starts the EDT after it's creation or after stopping.
boolean	waitUntilIdle() Wait until the EDT task queue is empty. The last task may still be in execution when this method returns.
boolean	waitUntilStopped() Wait until EDT task is stopped. No stop action is performed, invokeStop(boolean, java.lang.Runnable) should be used before.

Field Detail

defaultEDTPollPeriod

static final long defaultEDTPollPeriod

See Also:

Constant Field Values

Method Detail

getPollPeriod

long getPollPeriod()

Returns:

poll period in milliseconds

setPollPeriod

void setPollPeriod(long ms)

Parameters:

ms - poll period in milliseconds

start

boolean start()
              throws IllegalStateException

Starts the EDT after it's creation or after stopping.

If the EDT is running, it must be stopped first and the caller should wait until it's stopped.

Returns:

true if EDT has been successfully restarted, otherwise false

Throws:

IllegalStateException - if EDT is running and not subject to be stopped, i.e. isRunning() returns true

See Also:

invokeStop(boolean, java.lang.Runnable), waitUntilStopped()

isCurrentThreadEDT

boolean isCurrentThreadEDT()

Returns true if the current thread is the event dispatch thread (EDT).

The EDT is the platform specific thread dispatching toolkit-events and executing toolkit-tasks enqueued via invoke(boolean, Runnable).

Usually it is the same thread as used to dequeue informal NEWTEvents (NEDT), see isCurrentThreadNEDT(), however, this may differ, e.g. SWT and AWT implementation.

isCurrentThreadNEDT

boolean isCurrentThreadNEDT()

Returns true if the current thread is the internal NEWT event dequeue thread (NEDT).

The NEDT is the NEWT thread used to dequeue informal NEWTEvents enqueued internally via DisplayImpl.enqueueEvent(boolean, NEWTEvent).

Usually it is the same thread as the EDT, see isCurrentThreadEDT(), however, this may differ, e.g. SWT and AWT implementation.

isCurrentThreadEDTorNEDT

boolean isCurrentThreadEDTorNEDT()

Returns true if either isCurrentThreadEDT() or isCurrentThreadNEDT() is true, otherwise false.

isRunning

boolean isRunning()

Returns:

True if EDT is running and not subject to be stopped.

invokeStop

boolean invokeStop(boolean wait,
                   Runnable finalTask)

Append the final task to the EDT task queue, signals EDT to stop.

If wait is true methods blocks until EDT is stopped.

task maybe null
Due to the nature of this method:

• All previous queued tasks will be finished.
• No new tasks are allowed, an Exception is thrown.
• Can be issued from within EDT, ie from within an enqueued task.
• start() may follow immediately, ie creating a new EDT

Returns:

true if task has been executed or queued for later execution, otherwise false

invoke

boolean invoke(boolean wait,
               Runnable task)

Appends task to the EDT task queue if current thread is not EDT, otherwise execute task immediately.

Wait until execution is finished if wait == true.

Can be issued from within EDT, ie from within an enqueued task.

Returns:

true if task has been executed or queued for later execution, otherwise false

waitUntilIdle

boolean waitUntilIdle()

Wait until the EDT task queue is empty.
The last task may still be in execution when this method returns.

Returns:

true if waited for idle, otherwise false, i.e. in case of current thread is EDT or NEDT

waitUntilStopped

boolean waitUntilStopped()

Wait until EDT task is stopped.
No stop action is performed, invokeStop(boolean, java.lang.Runnable) should be used before.

If caller thread is EDT or NEDT, this call will not block.

Returns:

true if stopped, otherwise false, i.e. in case of current thread is EDT or NEDT