text: /*************************************************************************/
  /*  godot_plugin_jni.cpp                                                 */
  /*************************************************************************/
  /*                       This file is part of:                           */
  /*                           GODOT ENGINE                                */
  /*                      https://godotengine.org                          */
  /*************************************************************************/
  /* Copyright (c) 2007-2020 Juan Linietsky, Ariel Manzur.                 */
  /* Copyright (c) 2014-2020 Godot Engine contributors (cf. AUTHORS.md).   */
  /*                                                                       */
  /* Permission is hereby granted, free of charge, to any person obtaining */
  /* a copy of this software and associated documentation files (the       */
  /* "Software"), to deal in the Software without restriction, including   */
  /* without limitation the rights to use, copy, modify, merge, publish,   */
  /* distribute, sublicense, and/or sell copies of the Software, and to    */
  /* permit persons to whom the Software is furnished to do so, subject to */
  /* the following conditions:                                             */
  /*                                                                       */
  /* The above copyright notice and this permission notice shall be        */
  /* included in all copies or substantial portions of the Software.       */
  /*                                                                       */
  /* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,       */
  /* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF    */
  /* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.*/
  /* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY  */
  /* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,  */
  /* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE     */
  /* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.                */
  /*************************************************************************/
  
  #include "godot_plugin_jni.h"
  
  #include <core/engine.h>
  #include <core/error_macros.h>
  #include <core/project_settings.h>
  #include <platform/android/api/jni_singleton.h>
  #include <platform/android/jni_utils.h>
  #include <platform/android/string_android.h>
  
  static HashMap<String, JNISingleton *> jni_singletons;
  
  extern "C" {
  
  JNIEXPORT void JNICALL Java_org_godotengine_godot_plugin_GodotPlugin_nativeRegisterSingleton(JNIEnv *env, jobject obj, jstring name) {
  	String singname = jstring_to_string(name, env);
  	JNISingleton *s = (JNISingleton *)ClassDB::instance("JNISingleton");
  	s->set_instance(env->NewGlobalRef(obj));
  	jni_singletons[singname] = s;
  
  	Engine::get_singleton()->add_singleton(Engine::Singleton(singname, s));
  	ProjectSettings::get_singleton()->set(singname, s);
  }
  
  JNIEXPORT void JNICALL Java_org_godotengine_godot_plugin_GodotPlugin_nativeRegisterMethod(JNIEnv *env, jobject obj, jstring sname, jstring name, jstring ret, jobjectArray args) {
  	String singname = jstring_to_string(sname, env);
  
  	ERR_FAIL_COND(!jni_singletons.has(singname));
  
  	JNISingleton *s = jni_singletons.get(singname);
  
  	String mname = jstring_to_string(name, env);
  	String retval = jstring_to_string(ret, env);
  	Vector<Variant::Type> types;
  	String cs = "(";
  
  	int stringCount = env->GetArrayLength(args);
  
  	for (int i = 0; i < stringCount; i++) {
  		jstring string = (jstring)env->GetObjectArrayElement(args, i);
  		const String rawString = jstring_to_string(string, env);
  		types.push_back(get_jni_type(rawString));
  		cs += get_jni_sig(rawString);
  	}
  
  	cs += ")";
  	cs += get_jni_sig(retval);
  	jclass cls = env->GetObjectClass(s->get_instance());
  	jmethodID mid = env->GetMethodID(cls, mname.ascii().get_data(), cs.ascii().get_data());
  	if (!mid) {
  		print_line("Failed getting method ID " + mname);
  	}
  
  	s->add_method(mname, mid, types, get_jni_type(retval));
  }
  
  JNIEXPORT void JNICALL Java_org_godotengine_godot_plugin_GodotPlugin_nativeRegisterSignal(JNIEnv *env, jobject obj, jstring j_plugin_name, jstring j_signal_name, jobjectArray j_signal_param_types) {
  	String singleton_name = jstring_to_string(j_plugin_name, env);
  
  	ERR_FAIL_COND(!jni_singletons.has(singleton_name));
  
  	JNISingleton *singleton = jni_singletons.get(singleton_name);
  
  	String signal_name = jstring_to_string(j_signal_name, env);
  	Vector<Variant::Type> types;
  
  	int stringCount = env->GetArrayLength(j_signal_param_types);
  
  	for (int i = 0; i < stringCount; i++) {
  		jstring j_signal_param_type = (jstring)env->GetObjectArrayElement(j_signal_param_types, i);
  		const String signal_param_type = jstring_to_string(j_signal_param_type, env);
  		types.push_back(get_jni_type(signal_param_type));
  	}
  
  	singleton->add_signal(signal_name, types);
  }
  
  JNIEXPORT void JNICALL Java_org_godotengine_godot_plugin_GodotPlugin_nativeEmitSignal(JNIEnv *env, jobject obj, jstring j_plugin_name, jstring j_signal_name, jobjectArray j_signal_params) {
  	String singleton_name = jstring_to_string(j_plugin_name, env);
  
  	ERR_FAIL_COND(!jni_singletons.has(singleton_name));
  
  	JNISingleton *singleton = jni_singletons.get(singleton_name);
  
  	String signal_name = jstring_to_string(j_signal_name, env);
  
  	int count = env->GetArrayLength(j_signal_params);
  	ERR_FAIL_COND_MSG(count > VARIANT_ARG_MAX, "Maximum argument count exceeded!");
  
  	Variant variant_params[VARIANT_ARG_MAX];
  	const Variant *args[VARIANT_ARG_MAX];
  
  	for (int i = 0; i < count; i++) {
  		jobject j_param = env->GetObjectArrayElement(j_signal_params, i);
  		variant_params[i] = _jobject_to_variant(env, j_param);
  		args[i] = &variant_params[i];
  		env->DeleteLocalRef(j_param);
  	};
  
  	singleton->emit_signal(signal_name, args, count);
  }
  
  JNIEXPORT void JNICALL Java_org_godotengine_godot_plugin_GodotPlugin_nativeRegisterGDNativeLibraries(JNIEnv *env, jobject obj, jobjectArray gdnlib_paths) {
  	int gdnlib_count = env->GetArrayLength(gdnlib_paths);
  	if (gdnlib_count == 0) {
  		return;
  	}
  
  	// Retrieve the current list of gdnative libraries.
  	Array singletons = Array();
  	if (ProjectSettings::get_singleton()->has_setting("gdnative/singletons")) {
  		singletons = ProjectSettings::get_singleton()->get("gdnative/singletons");
  	}
  
  	// Insert the libraries provided by the plugin
  	for (int i = 0; i < gdnlib_count; i++) {
  		jstring relative_path = (jstring)env->GetObjectArrayElement(gdnlib_paths, i);
  
  		String path = "res://" + jstring_to_string(relative_path, env);
  		if (!singletons.has(path)) {
  			singletons.push_back(path);
  		}
  		env->DeleteLocalRef(relative_path);
  	}
  
  	// Insert the updated list back into project settings.
  	ProjectSettings::get_singleton()->set("gdnative/singletons", singletons);
  }
  }
  