[wpilib] Only read DS control word once in IterativeRobotBase (#3504)

wpilibc/src/main/native/include/frc/DSControlWord.h

@@ -0,0 +1,102 @@
+// 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 <hal/DriverStationTypes.h>
+
+namespace frc {
+
+/**
+ * A wrapper around Driver Station control word.
+ */
+class DSControlWord {
+ public:
+  /**
+   * DSControlWord constructor.
+   *
+   * Upon construction, the current Driver Station control word is read and
+   * stored internally.
+   */
+  DSControlWord();
+
+  /**
+   * Check if the DS has enabled the robot.
+   *
+   * @return True if the robot is enabled and the DS is connected
+   */
+  bool IsEnabled() const;
+
+  /**
+   * Check if the robot is disabled.
+   *
+   * @return True if the robot is explicitly disabled or the DS is not connected
+   */
+  bool IsDisabled() const;
+
+  /**
+   * Check if the robot is e-stopped.
+   *
+   * @return True if the robot is e-stopped
+   */
+  bool IsEStopped() const;
+
+  /**
+   * Check if the DS is commanding autonomous mode.
+   *
+   * @return True if the robot is being commanded to be in autonomous mode
+   */
+  bool IsAutonomous() const;
+
+  /**
+   * Check if the DS is commanding autonomous mode and if it has enabled the
+   * robot.
+   *
+   * @return True if the robot is being commanded to be in autonomous mode and
+   * enabled.
+   */
+  bool IsAutonomousEnabled() const;
+
+  /**
+   * Check if the DS is commanding teleop mode.
+   *
+   * @return True if the robot is being commanded to be in teleop mode
+   */
+  bool IsTeleop() const;
+
+  /**
+   * Check if the DS is commanding teleop mode and if it has enabled the robot.
+   *
+   * @return True if the robot is being commanded to be in teleop mode and
+   * enabled.
+   */
+  bool IsTeleopEnabled() const;
+
+  /**
+   * Check if the DS is commanding test mode.
+   *
+   * @return True if the robot is being commanded to be in test mode
+   */
+  bool IsTest() const;
+
+  /**
+   * Check if the DS is attached.
+   *
+   * @return True if the DS is connected to the robot
+   */
+  bool IsDSAttached() const;
+
+  /**
+   * Is the driver station attached to a Field Management System?
+   *
+   * @return True if the robot is competing on a field being controlled by a
+   *         Field Management System
+   */
+  bool IsFMSAttached() const;
+
+ private:
+  HAL_ControlWord m_controlWord;
+};
+
+}  // namespace frc