Android: Add new input mapping implementation

Source/Android/jni/Input/ControlReference.cpp

@@ -0,0 +1,54 @@
+// Copyright 2022 Dolphin Emulator Project
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#include "jni/Input/ControlReference.h"
+
+#include <string>
+
+#include <jni.h>
+
+#include "InputCommon/ControlReference/ControlReference.h"
+#include "jni/AndroidCommon/AndroidCommon.h"
+#include "jni/AndroidCommon/IDCache.h"
+
+ControlReference* ControlReferenceFromJava(JNIEnv* env, jobject control_reference)
+{
+  return reinterpret_cast<ControlReference*>(
+      env->GetLongField(control_reference, IDCache::GetControlReferencePointer()));
+}
+
+jobject ControlReferenceToJava(JNIEnv* env, ControlReference* control_reference)
+{
+  if (!control_reference)
+    return nullptr;
+
+  return env->NewObject(IDCache::GetControlReferenceClass(),
+                        IDCache::GetControlReferenceConstructor(),
+                        reinterpret_cast<jlong>(control_reference));
+}
+
+extern "C" {
+
+JNIEXPORT jdouble JNICALL
+Java_org_dolphinemu_dolphinemu_features_input_model_controlleremu_ControlReference_getState(
+    JNIEnv* env, jobject obj)
+{
+  return ControlReferenceFromJava(env, obj)->GetState<double>();
+}
+
+JNIEXPORT jstring JNICALL
+Java_org_dolphinemu_dolphinemu_features_input_model_controlleremu_ControlReference_getExpression(
+    JNIEnv* env, jobject obj)
+{
+  return ToJString(env, ControlReferenceFromJava(env, obj)->GetExpression());
+}
+
+JNIEXPORT jstring JNICALL
+Java_org_dolphinemu_dolphinemu_features_input_model_controlleremu_ControlReference_setExpression(
+    JNIEnv* env, jobject obj, jstring expr)
+{
+  const std::optional<std::string> result =
+      ControlReferenceFromJava(env, obj)->SetExpression(GetJString(env, expr));
+  return result ? ToJString(env, *result) : nullptr;
+}
+}