Add new C++ Command framework (#1785)

This is the C++ version of #1682.

The old command framework is still available, but will be deprecated.

Due to name conflicts, the new framework is in the frc2 namespace.
Eventually (after the old command framework is removed in a future year)
it will be moved into the main frc namespace.

wpilibcExamples/src/main/cpp/examples/Frisbeebot/include/RobotContainer.h

@@ -0,0 +1,102 @@
+/*----------------------------------------------------------------------------*/
+/* Copyright (c) 2019 FIRST. All Rights Reserved.                             */
+/* Open Source Software - may be modified and shared by FRC teams. The code   */
+/* must be accompanied by the FIRST BSD license file in the root directory of */
+/* the project.                                                               */
+/*----------------------------------------------------------------------------*/
+
+#pragma once
+
+#include <frc2/command/Command.h>
+#include <frc2/command/ConditionalCommand.h>
+#include <frc2/command/InstantCommand.h>
+#include <frc2/command/ParallelRaceGroup.h>
+#include <frc2/command/RunCommand.h>
+#include <frc2/command/SequentialCommandGroup.h>
+#include <frc2/command/WaitCommand.h>
+#include <frc2/command/WaitUntilCommand.h>
+
+#include <frc/XboxController.h>
+#include <frc/smartdashboard/SendableChooser.h>
+
+#include "Constants.h"
+#include "subsystems/DriveSubsystem.h"
+#include "subsystems/ShooterSubsystem.h"
+
+namespace ac = AutoConstants;
+
+/**
+ * This class is where the bulk of the robot should be declared.  Since
+ * Command-based is a "declarative" paradigm, very little robot logic should
+ * actually be handled in the {@link Robot} periodic methods (other than the
+ * scheduler calls).  Instead, the structure of the robot (including subsystems,
+ * commands, and button mappings) should be declared here.
+ */
+class RobotContainer {
+ public:
+  RobotContainer();
+
+  frc2::Command* GetAutonomousCommand();
+
+ private:
+  // The driver's controller
+  frc::XboxController m_driverController{OIConstants::kDriverControllerPort};
+
+  // The robot's subsystems and commands are defined here...
+
+  // The robot's subsystems
+  DriveSubsystem m_drive;
+  ShooterSubsystem m_shooter;
+
+  // A simple autonomous routine that shoots the loaded frisbees
+  frc2::SequentialCommandGroup m_autonomousCommand =
+      frc2::SequentialCommandGroup{
+          // Start the command by spinning up the shooter...
+          frc2::InstantCommand([this] { m_shooter.Enable(); }, {&m_shooter}),
+          // Wait until the shooter is at speed before feeding the frisbees
+          frc2::WaitUntilCommand([this] { return m_shooter.AtSetpoint(); }),
+          // Start running the feeder
+          frc2::InstantCommand([this] { m_shooter.RunFeeder(); }, {&m_shooter}),
+          // Shoot for the specified time
+          frc2::WaitCommand(ac::kAutoShootTimeSeconds)}
+          // Add a timeout (will end the command if, for instance, the shooter
+          // never gets up to
+          // speed)
+          .WithTimeout(ac::kAutoTimeoutSeconds)
+          // When the command ends, turn off the shooter and the feeder
+          .WhenFinished([this] {
+            m_shooter.Disable();
+            m_shooter.StopFeeder();
+          });
+
+  // Assorted commands to be bound to buttons
+
+  frc2::InstantCommand m_spinUpShooter{[this] { m_shooter.Enable(); },
+                                       {&m_shooter}};
+
+  frc2::InstantCommand m_stopShooter{[this] { m_shooter.Disable(); },
+                                     {&m_shooter}};
+
+  // Shoots if the shooter wheen has reached the target speed
+  frc2::ConditionalCommand m_shoot{
+      // Run the feeder
+      frc2::InstantCommand{[this] { m_shooter.RunFeeder(); }, {&m_shooter}},
+      // Do nothing
+      frc2::InstantCommand(),
+      // Determine which of the above to do based on whether the shooter has
+      // reached the
+      // desired speed
+      [this] { return m_shooter.AtSetpoint(); }};
+
+  frc2::InstantCommand m_stopFeeder{[this] { m_shooter.StopFeeder(); },
+                                    {&m_shooter}};
+
+  frc2::InstantCommand m_driveHalfSpeed{[this] { m_drive.SetMaxOutput(.5); },
+                                        {}};
+  frc2::InstantCommand m_driveFullSpeed{[this] { m_drive.SetMaxOutput(1); },
+                                        {}};
+
+  // The chooser for the autonomous routines
+
+  void ConfigureButtonBindings();
+};