Package edu.wpi.first.wpilibj.command

Class Scheduler

java.lang.Object

edu.wpi.first.wpilibj.command.Scheduler

All Implemented Interfaces:

NTSendable, Sendable, AutoCloseable

public final class Scheduler
extends Object
implements NTSendable, AutoCloseable

The Scheduler is a singleton which holds the top-level running commands. It is in charge of both calling the command's run() method and to make sure that there are no two commands with conflicting requirements running.

It is fine if teams wish to take control of the Scheduler themselves, all that needs to be done is to call Scheduler.getInstance().run() often to have Commands function correctly. However, this is already done for you if you use the CommandBased Robot template.

See Also:

Command

Method Summary

Modifier and Type	Method	Description
void	add(Command command)	Adds the command to the Scheduler.
void	addButton(Trigger.ButtonScheduler button)	Adds a button to the Scheduler.
void	close()
void	disable()	Disable the command scheduler.
void	enable()	Enable the command scheduler.
static Scheduler	getInstance()	Returns the Scheduler, creating it if one does not exist.
void	initSendable(NTSendableBuilder builder)	Initializes this Sendable object.
void	removeAll()	Removes all commands.
void	run()	Runs a single iteration of the loop.

Methods inherited from class java.lang.Object

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

Methods inherited from interface edu.wpi.first.networktables.NTSendable

initSendable

Method Details

getInstance

public static Scheduler getInstance()

Returns the Scheduler, creating it if one does not exist.

Returns:

the Scheduler

close

public void close()

Specified by:

close in interface AutoCloseable

add

public void add(Command command)

Adds the command to the Scheduler. This will not add the Command immediately, but will instead wait for the proper time in the run() loop before doing so. The command returns immediately and does nothing if given null.

Adding a Command to the Scheduler involves the Scheduler removing any Command which has shared requirements.

Parameters:

command - the command to add

addButton

public void addButton(Trigger.ButtonScheduler button)

Adds a button to the Scheduler. The Scheduler will poll the button during its run().

Parameters:

button - the button to add

run

public void run()

Runs a single iteration of the loop. This method should be called often in order to have a functioning Command system. The loop has five stages:

1. Poll the Buttons
2. Execute/Remove the Commands
3. Send values to SmartDashboard
4. Add Commands
5. Add Defaults

removeAll

public void removeAll()

Removes all commands.

disable

public void disable()

Disable the command scheduler.

enable

public void enable()

Enable the command scheduler.

initSendable

public void initSendable(NTSendableBuilder builder)

Description copied from interface: NTSendable

Initializes this Sendable object.

Specified by:

initSendable in interface NTSendable

Parameters:

builder - sendable builder