Simple Utilities

Simple Utilities

The Simple Utilities, located in the util and triggers packages, make developing robot code easier and more ergonomic by using lambdas to create WPILib components (Commands, Buttons, etc.) without having to create an entire anonymous class.

SimpleButton

SimpleButton is a way to create a WPILIb Button class based off of an arbitrary function returning a boolean in one line of code. This is useful if you want to set up complex control schemes; for example, having a button that is only considered pressed if a joystick is in a certain range.

Examples

Method reference:

Button fooButton = new SimpleButton(this::getFoo);

Simple statement lambda:

Button fooAndBarButton = new SimpleButton(() -> getFoo() && getBar());

More complicated logic:

Button atLeast5TrueButton = new SimpleButton(() -> {
    int numTrue = 0;
    for (boolean b : aListOfBooleans) {
        if (b) {
            numTrue++;
        }
    }
    return numTrue >= 5;
});

SimpleCommand/SimpleLoopCommand

SimpleCommand and SimpleLoopCommand are wrappers that allow the creation of WPILib Commands that run an arbitrary function when executed. SimpleCommand runs the provided code once before finishing, while SimpleLoopCommand will run until canceled or interrupted. Both types can have requirements just like normal commands.

Note that the constructor for SimpleCommand requires a name; this is so that the command has a sensible name that is preserved across different program runs (as otherwise the names could be different depending on what order something is initialized statically).

SimpleCommand in particular is very useful for putting buttons to do things on the SmartDashboard or Shuffleboard. Simply create the command and put it up using SmartDashboard.putData().

Examples

Hello world:

Command printHello = new SimpleCommand("Print hello", () -> System.out.println("Hello world!"));

Command with requirements:

Command openClaw = new SimpleCommand("Open claw", Robot.claw::open, Robot.claw);

Command with multiple requirements:

Command openClawAndRaiseArm = new SimpleCommand("Open Claw and Raise Arm",
    () -> {
        Robot.claw.open();
        Robot.arm.raise();
    }, 
    Robot.claw, Robot.arm);

Looping command:

Command printTime = new SimpleLoopCommand("Print Current Time", () -> System.out.println(System.currentTimeMillis()));

SimpleConditionalCommand

SimpleConditionalCommand is a wrapper that allows the creation of WPILib ConditionalCommand instances based off of an arbitrary function returning a boolean in one line of code. SimpleConditionalCommands, like ConditionalCommands, can run a Command only if the provided condition is true, or run one of two commands depending on the condition.

Examples

Run a command only if getFoo() returns true:

Command doSomethingIfFoo = new SimpleConditionalCommand(this::getFoo, new DoSomething());

Run the DoSomething command if getFoo() returns true, otherwise run DoSomethingElse:

Command somethingOrSomethingElse = new SimpleConditionalCommand(this::getFoo, 
    new DoSomething(), 
    new DoSomethingElse());