Remove the restriction on supported types for Godot Android plugins

The Android plugin implementation is updated to use `JavaClassWrapper` which was fixed in https://github.com/godotengine/godot/pull/96182, thus removing the limitation on supported types.

Note that `JavaClassWrapper` has also been updated in order to only provide access to public methods and constructor to GDScript.

6 files changed, 51 insertions, 208 deletions

diff --git a/platform/android/api/api.cpp b/platform/android/api/api.cpp
index 6920f801e5..078b9ab748 100644
--- a/platform/android/api/api.cpp
+++ b/platform/android/api/api.cpp
@@ -41,13 +41,11 @@ static JavaClassWrapper *java_class_wrapper = nullptr;
 
 void register_android_api() {
 #if !defined(ANDROID_ENABLED)
-	// On Android platforms, the `java_class_wrapper` instantiation and the
-	// `JNISingleton` registration occurs in
+	// On Android platforms, the `java_class_wrapper` instantiation occurs in
 	// `platform/android/java_godot_lib_jni.cpp#Java_org_godotengine_godot_GodotLib_setup`
-	java_class_wrapper = memnew(JavaClassWrapper); // Dummy
-	GDREGISTER_CLASS(JNISingleton);
+	java_class_wrapper = memnew(JavaClassWrapper);
 #endif
-
+	GDREGISTER_CLASS(JNISingleton);
 	GDREGISTER_CLASS(JavaClass);
 	GDREGISTER_CLASS(JavaObject);
 	GDREGISTER_CLASS(JavaClassWrapper);
@@ -108,7 +106,7 @@ Ref<JavaClass> JavaObject::get_java_class() const {
 
 JavaClassWrapper *JavaClassWrapper::singleton = nullptr;
 
-Ref<JavaClass> JavaClassWrapper::wrap(const String &) {
+Ref<JavaClass> JavaClassWrapper::_wrap(const String &, bool) {
 	return Ref<JavaClass>();
 }
 
diff --git a/platform/android/api/java_class_wrapper.h b/platform/android/api/java_class_wrapper.h
index 71f9c32318..c74cef8dd0 100644
--- a/platform/android/api/java_class_wrapper.h
+++ b/platform/android/api/java_class_wrapper.h
@@ -262,6 +262,8 @@ class JavaClassWrapper : public Object {
 	bool _get_type_sig(JNIEnv *env, jobject obj, uint32_t &sig, String &strsig);
 #endif
 
+	Ref<JavaClass> _wrap(const String &p_class, bool p_allow_private_methods_access);
+
 	static JavaClassWrapper *singleton;
 
 protected:
@@ -270,15 +272,14 @@ protected:
 public:
 	static JavaClassWrapper *get_singleton() { return singleton; }
 
-	Ref<JavaClass> wrap(const String &p_class);
+	Ref<JavaClass> wrap(const String &p_class) {
+		return _wrap(p_class, false);
+	}
 
 #ifdef ANDROID_ENABLED
-	Ref<JavaClass> wrap_jclass(jclass p_class);
-
-	JavaClassWrapper(jobject p_activity = nullptr);
-#else
-	JavaClassWrapper();
+	Ref<JavaClass> wrap_jclass(jclass p_class, bool p_allow_private_methods_access = false);
 #endif
+	JavaClassWrapper();
 };
 
 #endif // JAVA_CLASS_WRAPPER_H
diff --git a/platform/android/api/jni_singleton.h b/platform/android/api/jni_singleton.h
index 06afc4eb78..5e940819bc 100644
--- a/platform/android/api/jni_singleton.h
+++ b/platform/android/api/jni_singleton.h
@@ -31,193 +31,53 @@
 #ifndef JNI_SINGLETON_H
 #define JNI_SINGLETON_H
 
+#include "java_class_wrapper.h"
+
 #include "core/config/engine.h"
 #include "core/variant/variant.h"
 
-#ifdef ANDROID_ENABLED
-#include "jni_utils.h"
-#endif
-
 class JNISingleton : public Object {
 	GDCLASS(JNISingleton, Object);
 
-#ifdef ANDROID_ENABLED
 	struct MethodData {
-		jmethodID method;
 		Variant::Type ret_type;
 		Vector<Variant::Type> argtypes;
 	};
 
-	jobject instance;
 	RBMap<StringName, MethodData> method_map;
-#endif
+	Ref<JavaObject> wrapped_object;
 
 public:
 	virtual Variant callp(const StringName &p_method, const Variant **p_args, int p_argcount, Callable::CallError &r_error) override {
-#ifdef ANDROID_ENABLED
-		RBMap<StringName, MethodData>::Element *E = method_map.find(p_method);
-
-		// Check the method we're looking for is in the JNISingleton map and that
-		// the arguments match.
-		bool call_error = !E || E->get().argtypes.size() != p_argcount;
-		if (!call_error) {
-			for (int i = 0; i < p_argcount; i++) {
-				if (!Variant::can_convert(p_args[i]->get_type(), E->get().argtypes[i])) {
-					call_error = true;
-					break;
+		if (wrapped_object.is_valid()) {
+			RBMap<StringName, MethodData>::Element *E = method_map.find(p_method);
+
+			// Check the method we're looking for is in the JNISingleton map and that
+			// the arguments match.
+			bool call_error = !E || E->get().argtypes.size() != p_argcount;
+			if (!call_error) {
+				for (int i = 0; i < p_argcount; i++) {
+					if (!Variant::can_convert(p_args[i]->get_type(), E->get().argtypes[i])) {
+						call_error = true;
+						break;
+					}
 				}
 			}
-		}
-
-		if (call_error) {
-			// The method is not in this map, defaulting to the regular instance calls.
-			return Object::callp(p_method, p_args, p_argcount, r_error);
-		}
-
-		ERR_FAIL_NULL_V(instance, Variant());
-
-		r_error.error = Callable::CallError::CALL_OK;
-
-		jvalue *v = nullptr;
 
-		if (p_argcount) {
-			v = (jvalue *)alloca(sizeof(jvalue) * p_argcount);
-		}
-
-		JNIEnv *env = get_jni_env();
-
-		int res = env->PushLocalFrame(16);
-
-		ERR_FAIL_COND_V(res != 0, Variant());
-
-		List<jobject> to_erase;
-		for (int i = 0; i < p_argcount; i++) {
-			jvalret vr = _variant_to_jvalue(env, E->get().argtypes[i], p_args[i]);
-			v[i] = vr.val;
-			if (vr.obj) {
-				to_erase.push_back(vr.obj);
+			if (!call_error) {
+				return wrapped_object->callp(p_method, p_args, p_argcount, r_error);
 			}
 		}
 
-		Variant ret;
-
-		switch (E->get().ret_type) {
-			case Variant::NIL: {
-				env->CallVoidMethodA(instance, E->get().method, v);
-			} break;
-			case Variant::BOOL: {
-				ret = env->CallBooleanMethodA(instance, E->get().method, v) == JNI_TRUE;
-			} break;
-			case Variant::INT: {
-				ret = env->CallIntMethodA(instance, E->get().method, v);
-			} break;
-			case Variant::FLOAT: {
-				ret = env->CallFloatMethodA(instance, E->get().method, v);
-			} break;
-			case Variant::STRING: {
-				jobject o = env->CallObjectMethodA(instance, E->get().method, v);
-				ret = jstring_to_string((jstring)o, env);
-				env->DeleteLocalRef(o);
-			} break;
-			case Variant::PACKED_STRING_ARRAY: {
-				jobjectArray arr = (jobjectArray)env->CallObjectMethodA(instance, E->get().method, v);
-
-				ret = _jobject_to_variant(env, arr);
-
-				env->DeleteLocalRef(arr);
-			} break;
-			case Variant::PACKED_INT32_ARRAY: {
-				jintArray arr = (jintArray)env->CallObjectMethodA(instance, E->get().method, v);
-
-				int fCount = env->GetArrayLength(arr);
-				Vector<int> sarr;
-				sarr.resize(fCount);
-
-				int *w = sarr.ptrw();
-				env->GetIntArrayRegion(arr, 0, fCount, w);
-				ret = sarr;
-				env->DeleteLocalRef(arr);
-			} break;
-			case Variant::PACKED_INT64_ARRAY: {
-				jlongArray arr = (jlongArray)env->CallObjectMethodA(instance, E->get().method, v);
-
-				int fCount = env->GetArrayLength(arr);
-				Vector<int64_t> sarr;
-				sarr.resize(fCount);
-
-				int64_t *w = sarr.ptrw();
-				env->GetLongArrayRegion(arr, 0, fCount, w);
-				ret = sarr;
-				env->DeleteLocalRef(arr);
-			} break;
-			case Variant::PACKED_FLOAT32_ARRAY: {
-				jfloatArray arr = (jfloatArray)env->CallObjectMethodA(instance, E->get().method, v);
-
-				int fCount = env->GetArrayLength(arr);
-				Vector<float> sarr;
-				sarr.resize(fCount);
-
-				float *w = sarr.ptrw();
-				env->GetFloatArrayRegion(arr, 0, fCount, w);
-				ret = sarr;
-				env->DeleteLocalRef(arr);
-			} break;
-			case Variant::PACKED_FLOAT64_ARRAY: {
-				jdoubleArray arr = (jdoubleArray)env->CallObjectMethodA(instance, E->get().method, v);
-
-				int fCount = env->GetArrayLength(arr);
-				Vector<double> sarr;
-				sarr.resize(fCount);
-
-				double *w = sarr.ptrw();
-				env->GetDoubleArrayRegion(arr, 0, fCount, w);
-				ret = sarr;
-				env->DeleteLocalRef(arr);
-			} break;
-			case Variant::DICTIONARY: {
-				jobject obj = env->CallObjectMethodA(instance, E->get().method, v);
-				ret = _jobject_to_variant(env, obj);
-				env->DeleteLocalRef(obj);
-
-			} break;
-			case Variant::OBJECT: {
-				jobject obj = env->CallObjectMethodA(instance, E->get().method, v);
-				ret = _jobject_to_variant(env, obj);
-				env->DeleteLocalRef(obj);
-			} break;
-			default: {
-				env->PopLocalFrame(nullptr);
-				ERR_FAIL_V(Variant());
-			} break;
-		}
-
-		while (to_erase.size()) {
-			env->DeleteLocalRef(to_erase.front()->get());
-			to_erase.pop_front();
-		}
-
-		env->PopLocalFrame(nullptr);
-
-		return ret;
-#else // ANDROID_ENABLED
-
-		// Defaulting to the regular instance calls.
 		return Object::callp(p_method, p_args, p_argcount, r_error);
-#endif
 	}
 
-#ifdef ANDROID_ENABLED
-	jobject get_instance() const {
-		return instance;
+	Ref<JavaObject> get_wrapped_object() const {
+		return wrapped_object;
 	}
 
-	void set_instance(jobject p_instance) {
-		instance = p_instance;
-	}
-
-	void add_method(const StringName &p_name, jmethodID p_method, const Vector<Variant::Type> &p_args, Variant::Type p_ret_type) {
+	void add_method(const StringName &p_name, const Vector<Variant::Type> &p_args, Variant::Type p_ret_type) {
 		MethodData md;
-		md.method = p_method;
 		md.argtypes = p_args;
 		md.ret_type = p_ret_type;
 		method_map[p_name] = md;
@@ -232,24 +92,15 @@ public:
 		ADD_SIGNAL(mi);
 	}
 
-#endif
+	JNISingleton() {}
 
-	JNISingleton() {
-#ifdef ANDROID_ENABLED
-		instance = nullptr;
-#endif
+	JNISingleton(const Ref<JavaObject> &p_wrapped_object) {
+		wrapped_object = p_wrapped_object;
 	}
 
 	~JNISingleton() {
-#ifdef ANDROID_ENABLED
 		method_map.clear();
-		if (instance) {
-			JNIEnv *env = get_jni_env();
-			ERR_FAIL_NULL(env);
-
-			env->DeleteGlobalRef(instance);
-		}
-#endif
+		wrapped_object.unref();
 	}
 };
 
diff --git a/platform/android/java_class_wrapper.cpp b/platform/android/java_class_wrapper.cpp
index c92717e922..6bedbfd157 100644
--- a/platform/android/java_class_wrapper.cpp
+++ b/platform/android/java_class_wrapper.cpp
@@ -1120,7 +1120,7 @@ bool JavaClass::_convert_object_to_variant(JNIEnv *env, jobject obj, Variant &va
 	return false;
 }
 
-Ref<JavaClass> JavaClassWrapper::wrap(const String &p_class) {
+Ref<JavaClass> JavaClassWrapper::_wrap(const String &p_class, bool p_allow_private_methods_access) {
 	String class_name_dots = p_class.replace("/", ".");
 	if (class_cache.has(class_name_dots)) {
 		return class_cache[class_name_dots];
@@ -1175,7 +1175,7 @@ Ref<JavaClass> JavaClassWrapper::wrap(const String &p_class) {
 
 		jint mods = env->CallIntMethod(obj, is_constructor ? Constructor_getModifiers : Method_getModifiers);
 
-		if (!(mods & 0x0001)) {
+		if (!(mods & 0x0001) && (is_constructor || !p_allow_private_methods_access)) {
 			env->DeleteLocalRef(obj);
 			continue; //not public bye
 		}
@@ -1336,7 +1336,7 @@ Ref<JavaClass> JavaClassWrapper::wrap(const String &p_class) {
 	return java_class;
 }
 
-Ref<JavaClass> JavaClassWrapper::wrap_jclass(jclass p_class) {
+Ref<JavaClass> JavaClassWrapper::wrap_jclass(jclass p_class, bool p_allow_private_methods_access) {
 	JNIEnv *env = get_jni_env();
 	ERR_FAIL_NULL_V(env, Ref<JavaClass>());
 
@@ -1344,12 +1344,12 @@ Ref<JavaClass> JavaClassWrapper::wrap_jclass(jclass p_class) {
 	String class_name_string = jstring_to_string(class_name, env);
 	env->DeleteLocalRef(class_name);
 
-	return wrap(class_name_string);
+	return _wrap(class_name_string, p_allow_private_methods_access);
 }
 
 JavaClassWrapper *JavaClassWrapper::singleton = nullptr;
 
-JavaClassWrapper::JavaClassWrapper(jobject p_activity) {
+JavaClassWrapper::JavaClassWrapper() {
 	singleton = this;
 
 	JNIEnv *env = get_jni_env();
diff --git a/platform/android/java_godot_lib_jni.cpp b/platform/android/java_godot_lib_jni.cpp
index 6086f67a1e..1a256959cd 100644
--- a/platform/android/java_godot_lib_jni.cpp
+++ b/platform/android/java_godot_lib_jni.cpp
@@ -32,7 +32,6 @@
 
 #include "android_input_handler.h"
 #include "api/java_class_wrapper.h"
-#include "api/jni_singleton.h"
 #include "dir_access_jandroid.h"
 #include "display_server_android.h"
 #include "file_access_android.h"
@@ -209,8 +208,7 @@ JNIEXPORT jboolean JNICALL Java_org_godotengine_godot_GodotLib_setup(JNIEnv *env
 
 	TTS_Android::setup(p_godot_tts);
 
-	java_class_wrapper = memnew(JavaClassWrapper(godot_java->get_activity()));
-	GDREGISTER_CLASS(JNISingleton);
+	java_class_wrapper = memnew(JavaClassWrapper);
 	return true;
 }
 
diff --git a/platform/android/plugin/godot_plugin_jni.cpp b/platform/android/plugin/godot_plugin_jni.cpp
index 75c8dd9528..acb18cc5c5 100644
--- a/platform/android/plugin/godot_plugin_jni.cpp
+++ b/platform/android/plugin/godot_plugin_jni.cpp
@@ -30,6 +30,7 @@
 
 #include "godot_plugin_jni.h"
 
+#include "api/java_class_wrapper.h"
 #include "api/jni_singleton.h"
 #include "jni_utils.h"
 #include "string_android.h"
@@ -57,11 +58,15 @@ JNIEXPORT jboolean JNICALL Java_org_godotengine_godot_plugin_GodotPlugin_nativeR
 
 	ERR_FAIL_COND_V(jni_singletons.has(singname), false);
 
-	JNISingleton *s = (JNISingleton *)ClassDB::instantiate("JNISingleton");
-	s->set_instance(env->NewGlobalRef(obj));
-	jni_singletons[singname] = s;
+	jclass java_class = env->GetObjectClass(obj);
+	Ref<JavaClass> java_class_wrapped = JavaClassWrapper::get_singleton()->wrap_jclass(java_class, true);
+	env->DeleteLocalRef(java_class);
 
-	Engine::get_singleton()->add_singleton(Engine::Singleton(singname, s));
+	Ref<JavaObject> plugin_object = memnew(JavaObject(java_class_wrapped, obj));
+	JNISingleton *plugin_singleton = memnew(JNISingleton(plugin_object));
+	jni_singletons[singname] = plugin_singleton;
+
+	Engine::get_singleton()->add_singleton(Engine::Singleton(singname, plugin_singleton));
 	return true;
 }
 
@@ -75,7 +80,6 @@ JNIEXPORT void JNICALL Java_org_godotengine_godot_plugin_GodotPlugin_nativeRegis
 	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);
 
@@ -83,18 +87,9 @@ JNIEXPORT void JNICALL Java_org_godotengine_godot_plugin_GodotPlugin_nativeRegis
 		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));
+	s->add_method(mname, types, get_jni_type(retval));
 }
 
 JNIEXPORT void JNICALL Java_org_godotengine_godot_plugin_GodotPlugin_nativeRegisterSignal(JNIEnv *env, jclass clazz, jstring j_plugin_name, jstring j_signal_name, jobjectArray j_signal_param_types) {