[sim] Add SendableChooserSim (#6763)

Co-authored-by: Tyler Veness <calcmogul@gmail.com>
Co-authored-by: Joseph Eng <91924258+KangarooKoala@users.noreply.github.com>

wpilibc/src/main/native/cpp/simulation/SendableChooserSim.cpp

@@ -0,0 +1,24 @@
+// 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 "frc/simulation/SendableChooserSim.h"
+
+using namespace frc::sim;
+
+SendableChooserSim::SendableChooserSim(std::string_view path)
+    : SendableChooserSim(nt::NetworkTableInstance::GetDefault(), path) {}
+
+SendableChooserSim::SendableChooserSim(nt::NetworkTableInstance inst,
+                                       std::string_view path) {
+  if constexpr (RobotBase::IsSimulation()) {
+    m_publisher =
+        inst.GetStringTopic(fmt::format("{}{}", path, "selected")).Publish();
+  }
+}
+
+void SendableChooserSim::SetSelected(std::string_view option) {
+  if constexpr (RobotBase::IsSimulation()) {
+    m_publisher.Set(option);
+  }
+}

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

@@ -0,0 +1,46 @@
+// 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 <string_view>
+
+#include <networktables/NetworkTableInstance.h>
+#include <networktables/StringTopic.h>
+
+#include "frc/RobotBase.h"
+
+namespace frc::sim {
+
+/**
+ * Class that facilitates control of a SendableChooser's selected option in
+ * simulation.
+ */
+class SendableChooserSim {
+ public:
+  /**
+   * Constructs a SendableChooserSim.
+   *
+   * @param path The path where the SendableChooser is published.
+   */
+  explicit SendableChooserSim(std::string_view path);
+
+  /**
+   * Constructs a SendableChooserSim.
+   *
+   * @param inst The NetworkTables instance.
+   * @param path The path where the SendableChooser is published.
+   */
+  SendableChooserSim(nt::NetworkTableInstance inst, std::string_view path);
+
+  /**
+   * Set the selected option.
+   * @param option The option.
+   */
+  void SetSelected(std::string_view option);
+
+ private:
+  nt::StringPublisher m_publisher;
+};
+}  // namespace frc::sim