Added XboxController class (#140)

Joystick and Gamepad functionality was separated into cleaner interfaces.

wpilibc/shared/include/XboxController.h

@@ -0,0 +1,53 @@
+/*----------------------------------------------------------------------------*/
+/* Copyright (c) FIRST 2016. 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 "ErrorBase.h"
+#include "GamepadBase.h"
+
+namespace frc {
+
+class DriverStation;
+
+/**
+ * Handle input from Xbox 360 or Xbox One controllers connected to the Driver
+ * Station.
+ *
+ * This class handles Xbox input that comes from the Driver Station. Each time a
+ * value is requested the most recent value is returend. There is a single class
+ * instance for each controller and the mapping of ports to hardware buttons
+ * depends on the code in the Driver Station.
+ */
+class XboxController : public GamepadBase, public ErrorBase {
+ public:
+  explicit XboxController(int port);
+  virtual ~XboxController() = default;
+
+  XboxController(const XboxController&) = delete;
+  XboxController& operator=(const XboxController&) = delete;
+
+  float GetX(JoystickHand hand) const override;
+  float GetY(JoystickHand hand) const override;
+
+  bool GetBumper(JoystickHand hand) const override;
+  bool GetStickButton(JoystickHand hand) const override;
+
+  virtual float GetTriggerAxis(JoystickHand hand) const;
+
+  bool GetAButton() const;
+  bool GetBButton() const;
+  bool GetXButton() const;
+  bool GetYButton() const;
+  bool GetBackButton() const;
+  bool GetStartButton() const;
+
+ private:
+  DriverStation& m_ds;
+};
+
+}  // namespace frc