| /* |
| * Licensed to the Apache Software Foundation (ASF) under one |
| * or more contributor license agreements. See the NOTICE file |
| * distributed with this work for additional information |
| * regarding copyright ownership. The ASF licenses this file |
| * to you under the Apache License, Version 2.0 (the |
| * "License"); you may not use this file except in compliance |
| * with the License. You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, |
| * software distributed under the License is distributed on an |
| * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY |
| * KIND, either express or implied. See the License for the |
| * specific language governing permissions and limitations |
| * under the License. |
| */ |
| package org.netbeans.modules.javascript.cdnjs; |
| |
| import java.util.EventListener; |
| import java.util.List; |
| import java.util.concurrent.CopyOnWriteArrayList; |
| import org.netbeans.api.annotations.common.NonNull; |
| import org.netbeans.api.annotations.common.NullAllowed; |
| import org.netbeans.api.project.Project; |
| |
| /** |
| * Defines an object which listens for changes in CDNJS libraries. |
| */ |
| public interface LibraryListener extends EventListener { |
| |
| /** |
| * This method is called when libraries in a project change. |
| * @param project project which libraries has changed |
| */ |
| void librariesChanged(@NonNull Project project); |
| |
| //~ Inner classes |
| |
| /** |
| * Support class for working with {@link LibraryListener}. |
| * <p> |
| * This class is thread safe. |
| */ |
| final class Support { |
| |
| private final List<LibraryListener> listeners = new CopyOnWriteArrayList<>(); |
| |
| |
| /** |
| * Adds a {@link LibraryListener} to the listener list. The same |
| * listener object may be added more than once, and will be called |
| * as many times as it is added. If {@code listener} is {@code null}, |
| * no exception is thrown and no action is taken. |
| * @param listener the {@link LibraryListener} to be added, can be {@code null} |
| */ |
| public void addLibraryListener(@NullAllowed LibraryListener listener) { |
| if (listener == null) { |
| return; |
| } |
| listeners.add(listener); |
| } |
| |
| /** |
| * Removes a {@link LibraryListener} from the listener list. |
| * If {@code listener} was added more than once, |
| * it will be notified one less time after being removed. |
| * If {@code listener} is {@code null}, or was never added, no exception is |
| * thrown and no action is taken. |
| * @param listener the {@link LibraryListener} to be removed, can be {@code null} |
| */ |
| public void removeLibraryListener(@NullAllowed LibraryListener listener) { |
| if (listener == null) { |
| return; |
| } |
| listeners.remove(listener); |
| } |
| |
| /** |
| * Fires an event in libraries of the given project. |
| * @param project project which libraries have changed |
| */ |
| public void fireLibrariesChanged(@NonNull Project project) { |
| assert project != null; |
| for (LibraryListener listener : listeners) { |
| listener.librariesChanged(project); |
| } |
| } |
| |
| /** |
| * Checks if there are any listeners registered to this {@code Support}. |
| * @return {@code true} if there are one or more listeners, {@code false} otherwise. |
| */ |
| public boolean hasListeners() { |
| return !listeners.isEmpty(); |
| } |
| |
| } |
| |
| } |