Class CommandGroup

java.lang.Object
edu.wpi.first.wpilibj.command.Command
edu.wpi.first.wpilibj.command.CommandGroup
All Implemented Interfaces:
Sendable, AutoCloseable

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(...).

This class is provided by the OldCommands VendorDep

See Also:
Command, Subsystem, IllegalUseOfCommandException
  • Constructor Details

  • Method Details

    • addSequential

      public final void addSequential​(Command command)
      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:
      IllegalUseOfCommandException - if the group has been started before or been given to another group
      IllegalArgumentException - if command is null
    • addSequential

      public final void addSequential​(Command command, double timeout)
      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:
      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
      IllegalArgumentException - if command is null or timeout is negative
    • addParallel

      public final void addParallel​(Command command)
      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:
      IllegalUseOfCommandException - if the group has been started before or been given to another command group
      IllegalArgumentException - if command is null
    • addParallel

      public final void addParallel​(Command command, double timeout)
      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:
      IllegalUseOfCommandException - if the group has been started before or been given to another command group
      IllegalArgumentException - if command is null
    • isFinished

      protected boolean isFinished()
      Returns true if all the Commands in this group have been started and have finished.

      Teams may override this method, although they should probably reference super.isFinished() if they do.

      Specified by:
      isFinished in class Command
      Returns:
      whether this CommandGroup is finished
      See Also:
      isTimedOut()
    • initialize

      protected void initialize()
      Description copied from class: Command
      The initialize method is called the first time this Command is run after being started.
      Overrides:
      initialize in class Command
    • execute

      protected void execute()
      Description copied from class: Command
      The execute method is called repeatedly until this Command either finishes or is canceled.
      Overrides:
      execute in class Command
    • end

      protected void end()
      Description copied from class: Command
      Called when the command ended peacefully. This is where you may want to wrap up loose ends, like shutting off a motor that was being used in the command.
      Overrides:
      end in class Command
    • interrupted

      protected void interrupted()
      Description copied from class: Command
      Called when the command ends because somebody called cancel() or another command shared the same requirements as this one, and booted it out.

      This is where you may want to wrap up loose ends, like shutting off a motor that was being used in the command.

      Generally, it is useful to simply call the end() method within this method, as done here.

      Overrides:
      interrupted in class Command
    • isInterruptible

      public boolean isInterruptible()
      Returns whether or not this group is interruptible. A command group will be uninterruptible if setInterruptible(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.