[sim] Move Sim classes from HAL to wpilibc/j (#2549)

Also move some things in HAL for consistency.

WAS:
C++:
- C APIs: #include "mockdata/AccelerometerData.h"
- User side class: #include "simulation/AccelerometerSim.h"
Java:
- JNI APIs: hal.sim.mockdata.AccelerometerData (and a few classes in hal.sim)
- User side classes: hal.sim.AccelerometerSim

IS:
C++:
- C APIs: #include "hal/simulation/AccelerometerData.h"
- C++ class: #include "frc/simulation/AccelerometerSim.h"
Java:
- JNI APIs: hal.simulation.AccelerometerData
- User side class: wpilibj.simulation.AccelerometerSim

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

@@ -0,0 +1,89 @@
+/*----------------------------------------------------------------------------*/
+/* Copyright (c) 2018-2020 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 <memory>
+#include <utility>
+
+#include <hal/simulation/RelayData.h>
+
+#include "CallbackStore.h"
+
+namespace frc {
+namespace sim {
+class RelaySim {
+ public:
+  explicit RelaySim(int index) { m_index = index; }
+
+  std::unique_ptr<CallbackStore> RegisterInitializedForwardCallback(
+      NotifyCallback callback, bool initialNotify) {
+    auto store = std::make_unique<CallbackStore>(
+        m_index, -1, callback, &HALSIM_CancelRelayInitializedForwardCallback);
+    store->SetUid(HALSIM_RegisterRelayInitializedForwardCallback(
+        m_index, &CallbackStoreThunk, store.get(), initialNotify));
+    return store;
+  }
+
+  bool GetInitializedForward() const {
+    return HALSIM_GetRelayInitializedForward(m_index);
+  }
+
+  void SetInitializedForward(bool initializedForward) {
+    HALSIM_SetRelayInitializedForward(m_index, initializedForward);
+  }
+
+  std::unique_ptr<CallbackStore> RegisterInitializedReverseCallback(
+      NotifyCallback callback, bool initialNotify) {
+    auto store = std::make_unique<CallbackStore>(
+        m_index, -1, callback, &HALSIM_CancelRelayInitializedReverseCallback);
+    store->SetUid(HALSIM_RegisterRelayInitializedReverseCallback(
+        m_index, &CallbackStoreThunk, store.get(), initialNotify));
+    return store;
+  }
+
+  bool GetInitializedReverse() const {
+    return HALSIM_GetRelayInitializedReverse(m_index);
+  }
+
+  void SetInitializedReverse(bool initializedReverse) {
+    HALSIM_SetRelayInitializedReverse(m_index, initializedReverse);
+  }
+
+  std::unique_ptr<CallbackStore> RegisterForwardCallback(
+      NotifyCallback callback, bool initialNotify) {
+    auto store = std::make_unique<CallbackStore>(
+        m_index, -1, callback, &HALSIM_CancelRelayForwardCallback);
+    store->SetUid(HALSIM_RegisterRelayForwardCallback(
+        m_index, &CallbackStoreThunk, store.get(), initialNotify));
+    return store;
+  }
+
+  bool GetForward() const { return HALSIM_GetRelayForward(m_index); }
+
+  void SetForward(bool forward) { HALSIM_SetRelayForward(m_index, forward); }
+
+  std::unique_ptr<CallbackStore> RegisterReverseCallback(
+      NotifyCallback callback, bool initialNotify) {
+    auto store = std::make_unique<CallbackStore>(
+        m_index, -1, callback, &HALSIM_CancelRelayReverseCallback);
+    store->SetUid(HALSIM_RegisterRelayReverseCallback(
+        m_index, &CallbackStoreThunk, store.get(), initialNotify));
+    return store;
+  }
+
+  bool GetReverse() const { return HALSIM_GetRelayReverse(m_index); }
+
+  void SetReverse(bool reverse) { HALSIM_SetRelayReverse(m_index, reverse); }
+
+  void ResetData() { HALSIM_ResetRelayData(m_index); }
+
+ private:
+  int m_index;
+};
+}  // namespace sim
+}  // namespace frc