/
AnnotatedSubscriberFinder.java
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/
AnnotatedSubscriberFinder.java
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/*
* WorldEdit, a Minecraft world manipulation toolkit
* Copyright (C) sk89q <http://www.sk89q.com>
* Copyright (C) WorldEdit team and contributors
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <https://www.gnu.org/licenses/>.
*/
package com.sk89q.worldedit.util.eventbus;
import com.google.common.collect.HashMultimap;
import com.google.common.collect.Multimap;
import java.lang.invoke.MethodHandle;
import java.lang.invoke.MethodHandles;
import java.lang.reflect.Method;
/**
* A {@link SubscriberFindingStrategy} for collecting all event handler methods
* that are marked with the {@link Subscribe} annotation.
*
* <p>Original for Guava, licensed under the Apache License, Version 2.0.</p>
*/
class AnnotatedSubscriberFinder implements SubscriberFindingStrategy {
/**
* {@inheritDoc}
*
* <p>
* This implementation finds all methods marked with a {@link Subscribe}
* annotation.
* </p>
*/
@Override
public Multimap<Class<?>, EventHandler> findAllSubscribers(Object listener) {
Multimap<Class<?>, EventHandler> methodsInListener = HashMultimap.create();
Class<?> clazz = listener.getClass();
while (clazz != null) {
for (Method method : clazz.getMethods()) {
Subscribe annotation = method.getAnnotation(Subscribe.class);
method.setAccessible(true);
if (annotation != null) {
Class<?>[] parameterTypes = method.getParameterTypes();
if (parameterTypes.length != 1) {
throw new IllegalArgumentException(
"Method " + method + " has @Subscribe annotation, but requires "
+ parameterTypes.length + " arguments. Event handler methods "
+ "must require a single argument."
);
}
Class<?> eventType = parameterTypes[0];
MethodHandle handle;
try {
handle = MethodHandles.publicLookup().unreflect(method);
} catch (IllegalAccessException e) {
throw new IllegalArgumentException("Method " + method + " failed to unreflect.", e);
}
EventHandler handler = new MethodHandleEventHandler(annotation.priority(), listener, handle, method.getName());
methodsInListener.put(eventType, handler);
}
}
clazz = clazz.getSuperclass();
}
return methodsInListener;
}
}