[examples] Update Command-based starter project (#4778)

wpilibcExamples/src/main/cpp/templates/commandbased/cpp/Robot.cpp

@@ -4,7 +4,6 @@
 
 #include "Robot.h"
 
-#include <frc/smartdashboard/SmartDashboard.h>
 #include <frc2/command/CommandScheduler.h>
 
 void Robot::RobotInit() {}
@@ -37,7 +36,7 @@ void Robot::DisabledPeriodic() {}
 void Robot::AutonomousInit() {
   m_autonomousCommand = m_container.GetAutonomousCommand();
 
-  if (m_autonomousCommand != nullptr) {
+  if (m_autonomousCommand) {
     m_autonomousCommand->Schedule();
   }
 }
@@ -49,9 +48,8 @@ void Robot::TeleopInit() {
   // teleop starts running. If you want the autonomous to
   // continue until interrupted by another command, remove
   // this line or comment it out.
-  if (m_autonomousCommand != nullptr) {
+  if (m_autonomousCommand) {
     m_autonomousCommand->Cancel();
-    m_autonomousCommand = nullptr;
   }
 }
 

wpilibcExamples/src/main/cpp/templates/commandbased/cpp/RobotContainer.cpp

@@ -4,18 +4,20 @@
 
 #include "RobotContainer.h"
 
-RobotContainer::RobotContainer() : m_autonomousCommand(&m_subsystem) {
+#include "commands/Autos.h"
+
+RobotContainer::RobotContainer() {
   // Initialize all of your commands and subsystems here
 
   // Configure the button bindings
-  ConfigureButtonBindings();
+  ConfigureBindings();
 }
 
-void RobotContainer::ConfigureButtonBindings() {
+void RobotContainer::ConfigureBindings() {
   // Configure your button bindings here
 }
 
-frc2::Command* RobotContainer::GetAutonomousCommand() {
+frc2::CommandPtr RobotContainer::GetAutonomousCommand() {
   // An example command will be run in autonomous
-  return &m_autonomousCommand;
+  return autos::ExampleAuto(&m_subsystem);
 }

wpilibcExamples/src/main/cpp/templates/commandbased/cpp/commands/Autos.cpp

@@ -0,0 +1,14 @@
+// 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.
+
+#include "commands/Autos.h"
+
+#include <frc2/command/Commands.h>
+
+#include "commands/ExampleCommand.h"
+
+frc2::CommandPtr autos::ExampleAuto(ExampleSubsystem* subsystem) {
+  return frc2::cmd::Sequence(subsystem->ExampleMethodCommand(),
+                             ExampleCommand(subsystem).ToPtr());
+}

wpilibcExamples/src/main/cpp/templates/commandbased/cpp/commands/ExampleCommand.cpp

@@ -5,4 +5,7 @@
 #include "commands/ExampleCommand.h"
 
 ExampleCommand::ExampleCommand(ExampleSubsystem* subsystem)
-    : m_subsystem{subsystem} {}
+    : m_subsystem{subsystem} {
+  // Register that this command requires the subsystem.
+  AddRequirements(m_subsystem);
+}

wpilibcExamples/src/main/cpp/templates/commandbased/cpp/subsystems/ExampleSubsystem.cpp

@@ -8,6 +8,12 @@ ExampleSubsystem::ExampleSubsystem() {
   // Implementation of subsystem constructor goes here.
 }
 
+frc2::CommandPtr ExampleSubsystem::ExampleMethodCommand() {
+  // Inline construction of command goes here.
+  // Subsystem::RunOnce implicitly requires `this` subsystem.
+  return RunOnce([/* this */] { /* one-time action goes here */ });
+}
+
 void ExampleSubsystem::Periodic() {
   // Implementation of subsystem periodic method goes here.
 }

wpilibcExamples/src/main/cpp/templates/commandbased/include/Robot.h

@@ -4,8 +4,10 @@
 
 #pragma once
 
+#include <optional>
+
 #include <frc/TimedRobot.h>
-#include <frc2/command/Command.h>
+#include <frc2/command/CommandPtr.h>
 
 #include "RobotContainer.h"
 
@@ -24,9 +26,9 @@ class Robot : public frc::TimedRobot {
   void SimulationPeriodic() override;
 
  private:
-  // Have it null by default so that if testing teleop it
+  // Have it empty by default so that if testing teleop it
   // doesn't have undefined behavior and potentially crash.
-  frc2::Command* m_autonomousCommand = nullptr;
+  std::optional<frc2::CommandPtr> m_autonomousCommand;
 
   RobotContainer m_container;
 };

wpilibcExamples/src/main/cpp/templates/commandbased/include/RobotContainer.h

@@ -4,9 +4,8 @@
 
 #pragma once
 
-#include <frc2/command/Command.h>
+#include <frc2/command/CommandPtr.h>
 
-#include "commands/ExampleCommand.h"
 #include "subsystems/ExampleSubsystem.h"
 
 /**
@@ -20,12 +19,11 @@ class RobotContainer {
  public:
   RobotContainer();
 
-  frc2::Command* GetAutonomousCommand();
+  frc2::CommandPtr GetAutonomousCommand();
 
  private:
-  // The robot's subsystems and commands are defined here...
+  // The robot's subsystems are defined here...
   ExampleSubsystem m_subsystem;
-  ExampleCommand m_autonomousCommand;
 
-  void ConfigureButtonBindings();
+  void ConfigureBindings();
 };

wpilibcExamples/src/main/cpp/templates/commandbased/include/commands/Autos.h

@@ -0,0 +1,16 @@
+// 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.
+
+#pragma once
+
+#include <frc2/command/CommandPtr.h>
+
+#include "subsystems/ExampleSubsystem.h"
+
+namespace autos {
+/**
+ * Example static factory for an autonomous command.
+ */
+frc2::CommandPtr ExampleAuto(ExampleSubsystem* subsystem);
+}  // namespace autos

wpilibcExamples/src/main/cpp/templates/commandbased/include/subsystems/ExampleSubsystem.h

@@ -4,12 +4,18 @@
 
 #pragma once
 
+#include <frc2/command/CommandPtr.h>
 #include <frc2/command/SubsystemBase.h>
 
 class ExampleSubsystem : public frc2::SubsystemBase {
  public:
   ExampleSubsystem();
 
+  /**
+   * Example command factory method.
+   */
+  frc2::CommandPtr ExampleMethodCommand();
+
   /**
    * Will be called periodically whenever the CommandScheduler runs.
    */

wpilibjExamples/src/main/java/edu/wpi/first/wpilibj/templates/commandbased/RobotContainer.java

@@ -6,7 +6,7 @@ package edu.wpi.first.wpilibj.templates.commandbased;
 
 import edu.wpi.first.wpilibj.GenericHID;
 import edu.wpi.first.wpilibj.XboxController;
-import edu.wpi.first.wpilibj.templates.commandbased.commands.ExampleCommand;
+import edu.wpi.first.wpilibj.templates.commandbased.commands.Autos;
 import edu.wpi.first.wpilibj.templates.commandbased.subsystems.ExampleSubsystem;
 import edu.wpi.first.wpilibj2.command.Command;
 
@@ -20,12 +20,10 @@ public class RobotContainer {
   // The robot's subsystems and commands are defined here...
   private final ExampleSubsystem m_exampleSubsystem = new ExampleSubsystem();
 
-  private final ExampleCommand m_autoCommand = new ExampleCommand(m_exampleSubsystem);
-
   /** The container for the robot. Contains subsystems, OI devices, and commands. */
   public RobotContainer() {
     // Configure the button bindings
-    configureButtonBindings();
+    configureBindings();
   }
 
   /**
@@ -34,7 +32,7 @@ public class RobotContainer {
    * edu.wpi.first.wpilibj.Joystick} or {@link XboxController}), and then passing it to a {@link
    * edu.wpi.first.wpilibj2.command.button.JoystickButton}.
    */
-  private void configureButtonBindings() {}
+  private void configureBindings() {}
 
   /**
    * Use this to pass the autonomous command to the main {@link Robot} class.
@@ -42,7 +40,7 @@ public class RobotContainer {
    * @return the command to run in autonomous
    */
   public Command getAutonomousCommand() {
-    // An ExampleCommand will run in autonomous
-    return m_autoCommand;
+    // An example command will be run in autonomous
+    return Autos.exampleAuto(m_exampleSubsystem);
   }
 }

wpilibjExamples/src/main/java/edu/wpi/first/wpilibj/templates/commandbased/commands/Autos.java

@@ -0,0 +1,20 @@
+// 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.wpilibj.templates.commandbased.commands;
+
+import edu.wpi.first.wpilibj.templates.commandbased.subsystems.ExampleSubsystem;
+import edu.wpi.first.wpilibj2.command.CommandBase;
+import edu.wpi.first.wpilibj2.command.Commands;
+
+public final class Autos {
+  /** Example static factory for an autonomous command. */
+  public static CommandBase exampleAuto(ExampleSubsystem subsystem) {
+    return Commands.sequence(subsystem.exampleMethodCommand(), new ExampleCommand(subsystem));
+  }
+
+  private Autos() {
+    throw new UnsupportedOperationException("This is a utility class!");
+  }
+}

wpilibjExamples/src/main/java/edu/wpi/first/wpilibj/templates/commandbased/subsystems/ExampleSubsystem.java

@@ -4,12 +4,27 @@
 
 package edu.wpi.first.wpilibj.templates.commandbased.subsystems;
 
+import edu.wpi.first.wpilibj2.command.CommandBase;
 import edu.wpi.first.wpilibj2.command.SubsystemBase;
 
 public class ExampleSubsystem extends SubsystemBase {
   /** Creates a new ExampleSubsystem. */
   public ExampleSubsystem() {}
 
+  /**
+   * Example command factory method.
+   *
+   * @return a command
+   */
+  public CommandBase exampleMethodCommand() {
+    // Inline construction of command goes here.
+    // Subsystem::RunOnce implicitly requires `this` subsystem.
+    return runOnce(
+        () -> {
+          /* one-time action goes here */
+        });
+  }
+
   @Override
   public void periodic() {
     // This method will be called once per scheduler run