edu.wpi.first.wpilibj.command

Class Subsystem

java.lang.Object

edu.wpi.first.wpilibj.SendableBase

edu.wpi.first.wpilibj.command.Subsystem

All Implemented Interfaces:

Sendable

Direct Known Subclasses:

PIDSubsystem

public abstract class Subsystem
extends SendableBase
implements Sendable

This class defines a major component of the robot.

A good example of a subsystem is the driveline, or a claw if the robot has one.

All motors should be a part of a subsystem. For instance, all the wheel motors should be a part of some kind of "Driveline" subsystem.

Subsystems are used within the command system as requirements for Command. Only one command which requires a subsystem can run at a time. Also, subsystems can have default commands which are started if there is no command running which requires this subsystem.

See Also:

Command

Constructor Summary

Constructors

Constructor and Description
Subsystem() Creates a subsystem.
Subsystem(java.lang.String name) Creates a subsystem with the given name.

Method Summary

Modifier and Type	Method and Description
void	addChild(Sendable child) Associate a Sendable with this Subsystem.
void	addChild(java.lang.String name, Sendable child) Associate a Sendable with this Subsystem.
Command	getCurrentCommand() Returns the command which currently claims this subsystem.
java.lang.String	getCurrentCommandName() Returns the current command name, or empty string if no current command.
Command	getDefaultCommand() Returns the default command (or null if there is none).
java.lang.String	getDefaultCommandName() Returns the default command name, or empty string is there is none.
protected abstract void	initDefaultCommand() Initialize the default command for a subsystem By default subsystems have no default command, but if they do, the default command is set with this method.
void	initSendable(SendableBuilder builder) Initializes this Sendable object.
void	periodic() When the run method of the scheduler is called this method will be called.
void	setDefaultCommand(Command command) Sets the default command.
java.lang.String	toString()

Methods inherited from class edu.wpi.first.wpilibj.SendableBase

addChild, free, getName, getSubsystem, setName, setName, setName, setSubsystem

Methods inherited from class java.lang.Object

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

Methods inherited from interface edu.wpi.first.wpilibj.Sendable

getName, getSubsystem, setName, setName, setSubsystem

Constructor Detail

Subsystem

public Subsystem(java.lang.String name)

Creates a subsystem with the given name.

Parameters:

name - the name of the subsystem

Subsystem

public Subsystem()

Creates a subsystem. This will set the name to the name of the class.

Method Detail

initDefaultCommand

protected abstract void initDefaultCommand()

Initialize the default command for a subsystem By default subsystems have no default command, but if they do, the default command is set with this method. It is called on all Subsystems by CommandBase in the users program after all the Subsystems are created.

periodic

public void periodic()

When the run method of the scheduler is called this method will be called.

setDefaultCommand

public void setDefaultCommand(Command command)

Sets the default command. If this is not called or is called with null, then there will be no default command for the subsystem.

WARNING: This should NOT be called in a constructor if the subsystem is a singleton.

Parameters:

command - the default command (or null if there should be none)

Throws:

IllegalUseOfCommandException - if the command does not require the subsystem

getDefaultCommand

public Command getDefaultCommand()

Returns the default command (or null if there is none).

Returns:

the default command

getDefaultCommandName

public java.lang.String getDefaultCommandName()

Returns the default command name, or empty string is there is none.

Returns:

the default command name

getCurrentCommand

public Command getCurrentCommand()

Returns the command which currently claims this subsystem.

Returns:

the command which currently claims this subsystem

getCurrentCommandName

public java.lang.String getCurrentCommandName()

Returns the current command name, or empty string if no current command.

Returns:

the current command name

addChild

public void addChild(java.lang.String name,
                     Sendable child)

Associate a Sendable with this Subsystem. Also update the child's name.

Parameters:

name - name to give child

child - sendable

addChild

public void addChild(Sendable child)

Associate a Sendable with this Subsystem.

Parameters:

child - sendable

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object

initSendable

public void initSendable(SendableBuilder builder)

Description copied from interface: Sendable

Initializes this Sendable object.

Specified by:

initSendable in interface Sendable

Parameters:

builder - sendable builder