[hal,wpilib] Move Alert to HAL (#8646)

SystemCore implementation is not yet connected to MRCComm.

wpilibc/src/main/native/cpp/driverstation/Alert.cpp

@@ -0,0 +1,52 @@
+// 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 "wpi/driverstation/Alert.hpp"
+
+#include <stdint.h>
+
+#include <string>
+
+#include "wpi/util/string.h"
+
+using namespace wpi;
+
+static HAL_AlertHandle CreateAlert(std::string_view group,
+                                   std::string_view text, Alert::Level level) {
+  WPI_String wpiGroup = wpi::util::make_string(group);
+  WPI_String wpiText = wpi::util::make_string(text);
+  int32_t status = 0;
+  return HAL_CreateAlert(&wpiGroup, &wpiText, static_cast<int32_t>(level),
+                         &status);
+}
+
+Alert::Alert(std::string_view text, Level type) : Alert("Alerts", text, type) {}
+
+Alert::Alert(std::string_view group, std::string_view text, Level type)
+    : m_handle{CreateAlert(group, text, type)} {}
+
+void Alert::Set(bool active) {
+  int32_t status = 0;
+  HAL_SetAlertActive(m_handle, active, &status);
+}
+
+bool Alert::Get() const {
+  int32_t status = 0;
+  return HAL_IsAlertActive(m_handle, &status);
+}
+
+void Alert::SetText(std::string_view text) {
+  WPI_String wpiText = wpi::util::make_string(text);
+  int32_t status = 0;
+  HAL_SetAlertText(m_handle, &wpiText, &status);
+}
+
+std::string Alert::GetText() const {
+  WPI_String wpiText;
+  int32_t status = 0;
+  HAL_GetAlertText(m_handle, &wpiText, &status);
+  std::string rv{wpiText.str, wpiText.len};
+  WPI_FreeString(&wpiText);
+  return rv;
+}