org.openimaj.time

Class Sequencer

java.lang.Object

org.openimaj.time.Sequencer

All Implemented Interfaces:

Runnable

public class Sequencer
extends Object
implements Runnable

An object that will fire events at specific times thereby sequencing objects into a stream. Can be used to trigger anything, such as animations on a slideshow or sequencing audio samples.

The class is parameterised on a Timecode object which will be used to determine whether actions should be triggered. The accuracy of the triggers can be determined by changing the internal timer tick of the sequencer. For example, if you know that actions will never occur more than once a second, you can set the tick to something near a second.

This class will automatically start the TimeKeeper running when it is run. The time of firing of an event cannot be guaranteed and an event will always be fired if

Author:

David Dupplaw (dpd@ecs.soton.ac.uk)

Created:

27 Nov 2011

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static interface	Sequencer.SequencedAction A class that can be sequenced by the sequencer can implement this interface.
static class	Sequencer.SequencerEvent An event in the sequencer, this represents an action occurring at a specific time.

Constructor Summary

Constructors

Constructor and Description
Sequencer(TimeKeeper<? extends Timecode> timeKeeper) Default constructor that instantiates a sequencer that will check for actions every 10 milliseconds using the given time keeper.
Sequencer(TimeKeeper<? extends Timecode> timeKeeper, long tickAccuracyMillis) Constructor that instantiates a sequencer that will check for actions at the given rate using the given time keeper.

Method Summary

Modifier and Type	Method and Description
void	addEvent(Sequencer.SequencerEvent event) Add an event to the sequencer.
TreeSet<Sequencer.SequencerEvent>	getEvents() Returns the set of events in this sequencer.
void	run()
void	setRemoveEventsWhenComplete(boolean rewc) Sets whether to remove events from the event list when they have been completed.
void	setRetryFailedEvents(boolean rfe) Sets whether failed events will be retried at the next processing time.

Methods inherited from class java.lang.Object

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

Constructor Detail

Sequencer

public Sequencer(TimeKeeper<? extends Timecode> timeKeeper)

Default constructor that instantiates a sequencer that will check for actions every 10 milliseconds using the given time keeper.

Parameters:

timeKeeper - The timekeeper to use

Sequencer

public Sequencer(TimeKeeper<? extends Timecode> timeKeeper,
                 long tickAccuracyMillis)

Constructor that instantiates a sequencer that will check for actions at the given rate using the given time keeper.

Parameters:

timeKeeper - The timekeeper to use

tickAccuracyMillis - How often the sequencer will check for events.

Method Detail

addEvent

public void addEvent(Sequencer.SequencerEvent event)

Add an event to the sequencer.

Parameters:

event - The event to add.

run

public void run()

Specified by:

run in interface Runnable

See Also:

Runnable.run()

getEvents

public TreeSet<Sequencer.SequencerEvent> getEvents()

Returns the set of events in this sequencer.

Returns:

The set of events in this sequencer.

setRetryFailedEvents

public void setRetryFailedEvents(boolean rfe)

Sets whether failed events will be retried at the next processing time.

Parameters:

rfe - TRUE to retry failed events.

setRemoveEventsWhenComplete

public void setRemoveEventsWhenComplete(boolean rewc)

Sets whether to remove events from the event list when they have been completed. Doing so will speed up the processing at each event check but events will be lost. A way around this is to set up all your events then use getEvents() to retrieve the list of events and clone it. Failed events will be removed from the list only if retryFailedEvents is set to false.

Parameters:

rewc - TRUE to remove successfully completed events.