godot/platform/android/api/jni_singleton.h

/**************************************************************************/
/*  jni_singleton.h                                                       */
/**************************************************************************/
/*                         This file is part of:                          */
/*                             GODOT ENGINE                               */
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/* Copyright (c) 2014-present Godot Engine contributors (see AUTHORS.md). */
/* Copyright (c) 2007-2014 Juan Linietsky, Ariel Manzur.                  */
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#pragma once

#include "java_class_wrapper.h"

#include "core/config/engine.h"
#include "core/templates/rb_map.h"
#include "core/variant/variant.h"

class JNISingleton : public Object {
	GDCLASS(JNISingleton, Object);

	struct MethodData {
		Variant::Type ret_type;
		Vector<Variant::Type> argtypes;
	};

	RBMap<StringName, MethodData> method_map;
	Ref<JavaObject> wrapped_object;

protected:
	static void _bind_methods() {
		ClassDB::bind_method(D_METHOD("has_java_method", "method"), &JNISingleton::has_java_method);
	}

public:
	virtual Variant callp(const StringName &p_method, const Variant **p_args, int p_argcount, Callable::CallError &r_error) override {
		// Godot methods take precedence.
		Variant ret = Object::callp(p_method, p_args, p_argcount, r_error);
		if (r_error.error == Callable::CallError::CALL_OK) {
			return ret;
		}

		// Check the method we're looking for is in the JNISingleton map.
		// This is done because JNISingletons register methods differently than wrapped JavaClass / JavaObject to allow
		// for access to private methods annotated with the @UsedByGodot annotation.
		// In the future, we should remove access to private methods and require that JNISingletons' methods exposed to
		// GDScript be all public, similarly to what we do for wrapped JavaClass / JavaObject methods. Doing so will
		// also allow dropping and deprecating the @UsedByGodot annotation.
		RBMap<StringName, MethodData>::Element *E = method_map.find(p_method);
		if (E) {
			if (wrapped_object.is_valid()) {
				return wrapped_object->callp(p_method, p_args, p_argcount, r_error);
			} else {
				r_error.error = Callable::CallError::CALL_ERROR_INSTANCE_IS_NULL;
			}
		}
		return Variant();
	}

	Ref<JavaObject> get_wrapped_object() const {
		return wrapped_object;
	}

	bool has_java_method(const StringName &p_method) const {
		return method_map.has(p_method);
	}

	void add_method(const StringName &p_name, const Vector<Variant::Type> &p_args, Variant::Type p_ret_type) {
		MethodData md;
		md.argtypes = p_args;
		md.ret_type = p_ret_type;
		method_map[p_name] = md;
	}

	void add_signal(const StringName &p_name, const Vector<Variant::Type> &p_args) {
		MethodInfo mi;
		mi.name = p_name;
		for (int i = 0; i < p_args.size(); i++) {
			mi.arguments.push_back(PropertyInfo(p_args[i], "arg" + itos(i + 1)));
		}
		ADD_SIGNAL(mi);
	}

	JNISingleton() {}

	JNISingleton(const Ref<JavaObject> &p_wrapped_object) {
		wrapped_object = p_wrapped_object;
	}

	~JNISingleton() {
		method_map.clear();
		wrapped_object.unref();
	}
};