Sometimes the behavior of a command needs to change depending on the environment.
Sometimes you need to run multiple commands in a sequence, and the commands change depending on the conditions.
However, directly binding a command to a button/Trigger/JoystickButton gives you little flexibility to change the behavior. Using DeferredCommand, you can create commands on the fly which have different behavior when you run them in a match.
Depending on your exact scenario, you may also need CommandComposer to create command sequences.
Also, sometimes you have a long command sequence(usually for autos,) and you'd prefer not to clog up RobotContainer. CommandComposer also solves that problem.
CommandComposer is a way to create long command groups without clogging up RobotContainer. This is particularly useful for auto command sequences, where using it makes the code significantly easier to read. To use it, create a static method in CommandComposer with a return type of Command, and write some logic. The logic might check some conditions and change a CommandGroup accordingly. It might just accept a few parameters, and pass them along to certain commands.
/**
*
* @param someCondition A condition that's either true or false
* @param position An enum representing positions
* @return
*/
public static Command createCommandSequence(boolean someCondition, Position position) {
// If some condition is true, go to the position
if (someCondition) {
return new ExampleCommand(position);
} else {
// If not, go to the middle first, then go to the position
return new SequentialCommandGroup(new ExampleCommand(Position.MIDDLE), new ExampleCommand(position));
}
}DeferredCommand allows command construction to be delayed until runtime(instead of robot initialization.)
When you need to create commands where their behavior changes depending on outside conditions, use DeferredCommand. To use it, use a lambda expression that returns a Command. A CommandComposer method can also be used in place of a Command, as the static methods should return a Command.
new DeferredCommand(() -> CommandComposer.createCommandSequence(true, Position.FAR), Set.of(m_subsystem));