Package edu.wpi.first.wpilibj.command

Class CommandGroup

java.lang.Object

edu.wpi.first.wpilibj.command.Command

edu.wpi.first.wpilibj.command.CommandGroup

public class CommandGroup
extends Command

A CommandGroup is a list of commands which are executed in sequence.

Commands in a CommandGroup are added using the addSequential(...) method and are called sequentially. CommandGroups are themselves commands and can be given to other CommandGroups.

CommandGroups will carry all of the requirements of their subcommands. Additional requirements can be specified by calling requires(...) normally in the constructor.

CommandGroups can also execute commands in parallel, simply by adding them using addParallel(...).

See Also:

Command, Subsystem, IllegalUseOfCommandException

Constructor Summary

Constructors

Constructor	Description
CommandGroup()	Creates a new CommandGroup.
CommandGroup(java.lang.String name)	Creates a new CommandGroup with the given name.

Method Summary

Modifier and Type	Method	Description
void	addParallel(Command command)	Adds a new child Command to the group.
void	addParallel(Command command, double timeout)	Adds a new child Command to the group with the given timeout.
void	addSequential(Command command)	Adds a new Command to the group.
void	addSequential(Command command, double timeout)	Adds a new Command to the group with a given timeout.
boolean	isInterruptible()	Returns whether or not this group is interruptible.

Methods inherited from class edu.wpi.first.wpilibj.command.Command

cancel, doesRequire, isCanceled, isCompleted, isRunning, setRunWhenDisabled, start, timeSinceInitialized, willRunWhenDisabled

Methods inherited from class java.lang.Object

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

Constructor Details

CommandGroup

public CommandGroup()

Creates a new CommandGroup. The name of this command will be set to its class name.

CommandGroup

public CommandGroup(java.lang.String name)

Creates a new CommandGroup with the given name.

Parameters:

name - the name for this command group

Throws:

java.lang.IllegalArgumentException - if name is null

Method Details

addSequential

public final void addSequential(Command command) throws java.lang.Exception

Adds a new Command to the group. The Command will be started after all the previously added Commands.

Note that any requirements the given Command has will be added to the group. For this reason, a Command's requirements can not be changed after being added to a group.

It is recommended that this method be called in the constructor.

Parameters:

command - The Command to be added

Throws:

java.lang.Exception

IllegalUseOfCommandException - if the group has been started before or been given to another group

java.lang.IllegalArgumentException - if command is null

addSequential

public final void addSequential(Command command, double timeout) throws java.lang.Exception

Adds a new Command to the group with a given timeout. The Command will be started after all the previously added commands.

Once the Command is started, it will be run until it finishes or the time expires, whichever is sooner. Note that the given Command will have no knowledge that it is on a timer.

Note that any requirements the given Command has will be added to the group. For this reason, a Command's requirements can not be changed after being added to a group.

It is recommended that this method be called in the constructor.

Parameters:

command - The Command to be added

timeout - The timeout (in seconds)

Throws:

java.lang.Exception

IllegalUseOfCommandException - if the group has been started before or been given to another group or if the Command has been started before or been given to another group

java.lang.IllegalArgumentException - if command is null or timeout is negative

addParallel

public final void addParallel(Command command) throws java.lang.Exception

Adds a new child Command to the group. The Command will be started after all the previously added Commands.

Instead of waiting for the child to finish, a CommandGroup will have it run at the same time as the subsequent Commands. The child will run until either it finishes, a new child with conflicting requirements is started, or the main sequence runs a Command with conflicting requirements. In the latter two cases, the child will be canceled even if it says it can't be interrupted.

Note that any requirements the given Command has will be added to the group. For this reason, a Command's requirements can not be changed after being added to a group.

It is recommended that this method be called in the constructor.

Parameters:

command - The command to be added

Throws:

java.lang.Exception

IllegalUseOfCommandException - if the group has been started before or been given to another command group

java.lang.IllegalArgumentException - if command is null

addParallel

public final void addParallel(Command command, double timeout) throws java.lang.Exception

Adds a new child Command to the group with the given timeout. The Command will be started after all the previously added Commands.

Once the Command is started, it will run until it finishes, is interrupted, or the time expires, whichever is sooner. Note that the given Command will have no knowledge that it is on a timer.

Instead of waiting for the child to finish, a CommandGroup will have it run at the same time as the subsequent Commands. The child will run until either it finishes, the timeout expires, a new child with conflicting requirements is started, or the main sequence runs a Command with conflicting requirements. In the latter two cases, the child will be canceled even if it says it can't be interrupted.

Note that any requirements the given Command has will be added to the group. For this reason, a Command's requirements can not be changed after being added to a group.

It is recommended that this method be called in the constructor.

Parameters:

command - The command to be added

timeout - The timeout (in seconds)

Throws:

java.lang.Exception

IllegalUseOfCommandException - if the group has been started before or been given to another command group

java.lang.IllegalArgumentException - if command is null

isInterruptible

public boolean isInterruptible()

Returns whether or not this group is interruptible. A command group will be uninterruptible if setInterruptable(false) was called or if it is currently running an uninterruptible command or child.

Overrides:

isInterruptible in class Command

Returns:

whether or not this CommandGroup is interruptible.