[sim] Add joystick simulation support (#2595)

This adds joystick functions to DriverStationSim, and new GenericHIDSim,
JoystickSim, and XboxControllerSim classes.

wpilibc/src/main/native/include/frc/simulation/XboxControllerSim.h

@@ -0,0 +1,111 @@
+/*----------------------------------------------------------------------------*/
+/* Copyright (c) 2020 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 "frc/XboxController.h"
+#include "frc/simulation/GenericHIDSim.h"
+
+namespace frc {
+namespace sim {
+
+/**
+ * Class to control a simulated Xbox 360 or Xbox One controller.
+ */
+class XboxControllerSim : public GenericHIDSim {
+ public:
+  /**
+   * Constructs from a XboxController object.
+   *
+   * @param joystick controller to simulate
+   */
+  explicit XboxControllerSim(const XboxController& joystick)
+      : GenericHIDSim{joystick} {
+    SetAxisCount(6);
+    SetButtonCount(10);
+  }
+
+  /**
+   * Constructs from a joystick port number.
+   *
+   * @param port port number
+   */
+  explicit XboxControllerSim(int port) : GenericHIDSim{port} {
+    SetAxisCount(6);
+    SetButtonCount(10);
+  }
+
+  void SetX(GenericHID::JoystickHand hand, double value) {
+    if (hand == GenericHID::kLeftHand) {
+      SetRawAxis(static_cast<int>(XboxController::Axis::kLeftX), value);
+    } else {
+      SetRawAxis(static_cast<int>(XboxController::Axis::kRightX), value);
+    }
+  }
+
+  void SetY(GenericHID::JoystickHand hand, double value) {
+    if (hand == GenericHID::kLeftHand) {
+      SetRawAxis(static_cast<int>(XboxController::Axis::kLeftY), value);
+    } else {
+      SetRawAxis(static_cast<int>(XboxController::Axis::kRightY), value);
+    }
+  }
+
+  void SetTriggerAxis(GenericHID::JoystickHand hand, double value) {
+    if (hand == GenericHID::kLeftHand) {
+      SetRawAxis(static_cast<int>(XboxController::Axis::kLeftTrigger), value);
+    } else {
+      SetRawAxis(static_cast<int>(XboxController::Axis::kRightTrigger), value);
+    }
+  }
+
+  void SetBumper(GenericHID::JoystickHand hand, bool state) {
+    if (hand == GenericHID::kLeftHand) {
+      SetRawButton(static_cast<int>(XboxController::Button::kBumperLeft),
+                   state);
+    } else {
+      SetRawButton(static_cast<int>(XboxController::Button::kBumperRight),
+                   state);
+    }
+  }
+
+  void SetStickButton(GenericHID::JoystickHand hand, bool state) {
+    if (hand == GenericHID::kLeftHand) {
+      SetRawButton(static_cast<int>(XboxController::Button::kStickLeft), state);
+    } else {
+      SetRawButton(static_cast<int>(XboxController::Button::kStickRight),
+                   state);
+    }
+  }
+
+  void SetAButton(bool state) {
+    SetRawButton(static_cast<int>(XboxController::Button::kA), state);
+  }
+
+  void SetBButton(bool state) {
+    SetRawButton(static_cast<int>(XboxController::Button::kB), state);
+  }
+
+  void SetXButton(bool state) {
+    SetRawButton(static_cast<int>(XboxController::Button::kX), state);
+  }
+
+  void SetYButton(bool state) {
+    SetRawButton(static_cast<int>(XboxController::Button::kY), state);
+  }
+
+  void SetBackButton(bool state) {
+    SetRawButton(static_cast<int>(XboxController::Button::kBack), state);
+  }
+
+  void SetStartButton(bool state) {
+    SetRawButton(static_cast<int>(XboxController::Button::kStart), state);
+  }
+};
+
+}  // namespace sim
+}  // namespace frc