[commands] Add command factories (#4476)

Co-authored-by: oblarg <emichaelbarnett@gmail.com>

wpilibNewCommands/src/main/java/edu/wpi/first/wpilibj2/command/Command.java

@@ -430,14 +430,32 @@ public interface Command {
   }
 
   /**
-   * Gets the name of this Command.
+   * Gets the name of this Command. Defaults to the simple class name if not overridden.
    *
-   * @return Name
+   * @return The display name of the Command
    */
   default String getName() {
     return this.getClass().getSimpleName();
   }
 
+  /**
+   * Sets the name of this Command. Nullop if not overridden.
+   *
+   * @param name The display name of the Command.
+   */
+  default void setName(String name) {}
+
+  /**
+   * Decorates this Command with a name. Is an inline function for #setName(String);
+   *
+   * @param name name
+   * @return the decorated Command
+   */
+  default Command withName(String name) {
+    this.setName(name);
+    return this;
+  }
+
   /**
    * An enum describing the command's behavior when another command with a shared requirement is
    * scheduled.

wpilibNewCommands/src/main/java/edu/wpi/first/wpilibj2/command/CommandBase.java

@@ -51,21 +51,11 @@ public abstract class CommandBase implements Sendable, Command {
    *
    * @param name name
    */
+  @Override
   public void setName(String name) {
     SendableRegistry.setName(this, name);
   }
 
-  /**
-   * Decorates this Command with a name. Is an inline function for #setName(String);
-   *
-   * @param name name
-   * @return the decorated Command
-   */
-  public CommandBase withName(String name) {
-    this.setName(name);
-    return this;
-  }
-
   /**
    * Gets the subsystem name of this Command.
    *

wpilibNewCommands/src/main/java/edu/wpi/first/wpilibj2/command/Commands.java

@@ -0,0 +1,210 @@
+// Copyright (c) FIRST and other WPILib contributors.
+// Open Source Software; you can modify and/or share it under the terms of
+// the WPILib BSD license file in the root directory of this project.
+
+package edu.wpi.first.wpilibj2.command;
+
+import static edu.wpi.first.wpilibj.util.ErrorMessages.requireNonNullParam;
+
+import java.util.Map;
+import java.util.function.BooleanSupplier;
+import java.util.function.Supplier;
+
+/**
+ * Namespace for command factory methods.
+ *
+ * <p>For convenience, you might want to static import the members of this class.
+ */
+public final class Commands {
+  /**
+   * Constructs a command that does nothing, finishing immediately.
+   *
+   * @return the command
+   */
+  public static Command none() {
+    return new InstantCommand();
+  }
+
+  // Action Commands
+
+  /**
+   * Constructs a command that runs an action once and finishes.
+   *
+   * @param action the action to run
+   * @param requirements subsystems the action requires
+   * @return the command
+   * @see InstantCommand
+   */
+  public static Command runOnce(Runnable action, Subsystem... requirements) {
+    return new InstantCommand(action, requirements);
+  }
+
+  /**
+   * Constructs a command that runs an action every iteration until interrupted.
+   *
+   * @param action the action to run
+   * @param requirements subsystems the action requires
+   * @return the command
+   * @see RunCommand
+   */
+  public static Command run(Runnable action, Subsystem... requirements) {
+    return new RunCommand(action, requirements);
+  }
+
+  /**
+   * Constructs a command that runs an action once and another action when the command is
+   * interrupted.
+   *
+   * @param start the action to run on start
+   * @param end the action to run on interrupt
+   * @param requirements subsystems the action requires
+   * @return the command
+   * @see StartEndCommand
+   */
+  public static Command startEnd(Runnable start, Runnable end, Subsystem... requirements) {
+    return new StartEndCommand(start, end, requirements);
+  }
+
+  /**
+   * Constructs a command that runs an action every iteration until interrupted, and then runs a
+   * second action.
+   *
+   * @param run the action to run every iteration
+   * @param end the action to run on interrupt
+   * @param requirements subsystems the action requires
+   * @return the command
+   */
+  public static Command runEnd(Runnable run, Runnable end, Subsystem... requirements) {
+    requireNonNullParam(end, "end", "Command.runEnd");
+    return new FunctionalCommand(
+        () -> {}, run, interrupted -> end.run(), () -> false, requirements);
+  }
+
+  /**
+   * Constructs a command that prints a message and finishes.
+   *
+   * @param message the message to print
+   * @return the command
+   * @see PrintCommand
+   */
+  public static Command print(String message) {
+    return new PrintCommand(message);
+  }
+
+  // Idling Commands
+
+  /**
+   * Constructs a command that does nothing, finishing after a specified duration.
+   *
+   * @param seconds after how long the command finishes
+   * @return the command
+   * @see WaitCommand
+   */
+  public static Command wait(double seconds) {
+    return new WaitCommand(seconds);
+  }
+
+  /**
+   * Constructs a command that does nothing, finishing once a command becomes true.
+   *
+   * @param condition the condition
+   * @return the command
+   * @see WaitUntilCommand
+   */
+  public static Command waitUntil(BooleanSupplier condition) {
+    return new WaitUntilCommand(condition);
+  }
+
+  // Selector Commands
+
+  /**
+   * Runs one of two commands, based on the boolean selector function.
+   *
+   * @param onTrue the command to run if the selector function returns true
+   * @param onFalse the command to run if the selector function returns false
+   * @param selector the selector function
+   * @return the command
+   * @see ConditionalCommand
+   */
+  public static Command either(Command onTrue, Command onFalse, BooleanSupplier selector) {
+    return new ConditionalCommand(onTrue, onFalse, selector);
+  }
+
+  /**
+   * Runs one of several commands, based on the selector function.
+   *
+   * @param selector the selector function
+   * @param commands map of commands to select from
+   * @return the command
+   * @see SelectCommand
+   */
+  public static Command select(Map<Object, Command> commands, Supplier<Object> selector) {
+    return new SelectCommand(commands, selector);
+  }
+
+  /**
+   * Runs a group of commands in series, one after the other.
+   *
+   * @param commands the commands to include
+   * @return the command group
+   * @see SequentialCommandGroup
+   */
+  public static Command sequence(Command... commands) {
+    return new SequentialCommandGroup(commands);
+  }
+
+  // Command Groups
+
+  /**
+   * Runs a group of commands in series, one after the other. Once the last command ends, the group
+   * is restarted.
+   *
+   * @param commands the commands to include
+   * @return the command group
+   * @see SequentialCommandGroup
+   * @see Command#repeatedly()
+   */
+  public static Command repeatingSequence(Command... commands) {
+    return sequence(commands).repeatedly();
+  }
+
+  /**
+   * Runs a group of commands at the same time. Ends once all commands in the group finish.
+   *
+   * @param commands the commands to include
+   * @return the command
+   * @see ParallelCommandGroup
+   */
+  public static Command parallel(Command... commands) {
+    return new ParallelCommandGroup(commands);
+  }
+
+  /**
+   * Runs a group of commands at the same time. Ends once any command in the group finishes, and
+   * cancels the others.
+   *
+   * @param commands the commands to include
+   * @return the command group
+   * @see ParallelRaceGroup
+   */
+  public static Command race(Command... commands) {
+    return new ParallelRaceGroup(commands);
+  }
+
+  /**
+   * Runs a group of commands at the same time. Ends once a specific command finishes, and cancels
+   * the others.
+   *
+   * @param deadline the deadline command
+   * @param commands the commands to include
+   * @return the command group
+   * @see ParallelDeadlineGroup
+   */
+  public static Command deadline(Command deadline, Command... commands) {
+    return new ParallelDeadlineGroup(deadline, commands);
+  }
+
+  private Commands() {
+    throw new UnsupportedOperationException("This is a utility class");
+  }
+}