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- /*
- * Copyright (c) 2006-2017 DMDirc Developers
- *
- * 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.
- */
-
- package com.dmdirc.util.collections;
-
- import java.lang.reflect.InvocationHandler;
- import java.lang.reflect.InvocationTargetException;
- import java.lang.reflect.Method;
- import java.lang.reflect.Proxy;
- import java.util.Collection;
- import java.util.HashMap;
- import java.util.Map;
- import java.util.concurrent.CopyOnWriteArrayList;
-
- /**
- * Represents a list of event listeners, similar to EventListenerList, but
- * not swing specific.
- */
- public class ListenerList {
-
- /** The map of class->listener or string->listener that we're using. */
- private final Map<Object, Collection<Object>> listeners = new HashMap<>();
-
- /**
- * Adds a new listener of the specified type to this listener list.
- *
- * @param <T> The type of listener to be added
- * @param listenerType The type of listener to be added
- * @param listener The listener to be added
- */
- public <T> void add(final Class<T> listenerType, final T listener) {
- if (listener == null) {
- throw new IllegalArgumentException("Listener cannot be null");
- }
- if (!listeners.containsKey(listenerType)) {
- listeners.put(listenerType, new CopyOnWriteArrayList<>());
- }
-
- listeners.get(listenerType).add(listener);
- }
-
- /**
- * Adds a new listener of the specified type to this listener list.
- *
- * @param listenerType The name of the type of listener that's being added
- * @param listener The listener to be added
- */
- public void add(final String listenerType, final Object listener) {
- if (listener == null) {
- throw new IllegalArgumentException("Listener cannot be null");
- }
- if (!listeners.containsKey(listenerType)) {
- listeners.put(listenerType, new CopyOnWriteArrayList<>());
- }
-
- listeners.get(listenerType).add(listener);
- }
-
- /**
- * Removes the specified listener from the list of listeners for the
- * specified type.
- *
- * @param <T> The type of listener to be removed
- * @param listenerType The type that the listener should be removed from
- * @param listener The listener to be removed
- */
- public <T> void remove(final Class<T> listenerType, final T listener) {
- get(listenerType).remove(listener);
- }
-
- /**
- * Removes the specified listener from the list of listeners for the
- * specified type.
- *
- * @param listenerType The name of the type that the listener should be
- * removed from
- * @param listener The listener to be removed
- */
- public void remove(final String listenerType, final Object listener) {
- get(listenerType).remove(listener);
- }
-
- /**
- * Retrieves the list of listeners for the specified type.
- *
- * @param <T> The type of listener to be retrieved
- * @param listenerType The type of listener that's being retrieved
- * @return A list of listeners for the specified type
- */
- @SuppressWarnings("unchecked")
- public <T> Collection<T> get(final Class<T> listenerType) {
- if (listeners.containsKey(listenerType)) {
- return (Collection<T>) listeners.get(listenerType);
- } else {
- return new CopyOnWriteArrayList<>();
- }
- }
-
- /**
- * Retrieves the list of listeners for the specified type.
- *
- * @param listenerType The type of listener to be retrieved
- * @return A list of listeners for the specified type
- */
- public Collection<Object> get(final String listenerType) {
- if (listeners.containsKey(listenerType)) {
- return listeners.get(listenerType);
- } else {
- return new CopyOnWriteArrayList<>();
- }
- }
-
- /**
- * Returns a callable proxy of the specified type. Methods called on the
- * returned proxy will be proxied to all of the registered listeners.
- *
- * @param <T> The type of listener to be called
- * @param listenerType The type of listener to be called
- * @return A proxy instance that can be used to call methods
- */
- @SuppressWarnings("unchecked")
- public <T> T getCallable(final Class<T> listenerType) {
- return (T) Proxy.newProxyInstance(listenerType.getClassLoader(),
- new Class<?>[] { listenerType }, new CallHandler<>(listenerType));
- }
-
- /**
- * Utility class to handle calls to a "callable" interface as returned by
- * {@link #getCallable(Class)}.
- *
- * @param <T> The type of listener being called
- */
- private class CallHandler<T> implements InvocationHandler {
-
- /** The type of listener this handler is handling. */
- private final Class<T> listenerType;
-
- /**
- * Creates a new call handler for the specified type of listener.
- *
- * @param listenerType The type of listener to handle
- */
- CallHandler(final Class<T> listenerType) {
- this.listenerType = listenerType;
- }
-
- @Override
- public Object invoke(final Object proxy, final Method method,
- final Object[] args) throws Throwable {
- for (T target : get(listenerType)) {
- try {
- method.invoke(target, args);
- } catch (IllegalAccessException | IllegalArgumentException ex) {
- // Ignore, not possible
- } catch (InvocationTargetException ex) {
- throw ex.getCause();
- }
- }
-
- return null;
- }
-
- }
-
- }
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