jaroslav@601: /*
jaroslav@601:  * Copyright (c) 2007, Oracle and/or its affiliates. All rights reserved.
jaroslav@601:  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
jaroslav@601:  *
jaroslav@601:  * This code is free software; you can redistribute it and/or modify it
jaroslav@601:  * under the terms of the GNU General Public License version 2 only, as
jaroslav@601:  * published by the Free Software Foundation.  Oracle designates this
jaroslav@601:  * particular file as subject to the "Classpath" exception as provided
jaroslav@601:  * by Oracle in the LICENSE file that accompanied this code.
jaroslav@601:  *
jaroslav@601:  * This code is distributed in the hope that it will be useful, but WITHOUT
jaroslav@601:  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
jaroslav@601:  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
jaroslav@601:  * version 2 for more details (a copy is included in the LICENSE file that
jaroslav@601:  * accompanied this code).
jaroslav@601:  *
jaroslav@601:  * You should have received a copy of the GNU General Public License version
jaroslav@601:  * 2 along with this work; if not, write to the Free Software Foundation,
jaroslav@601:  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
jaroslav@601:  *
jaroslav@601:  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
jaroslav@601:  * or visit www.oracle.com if you need additional information or have any
jaroslav@601:  * questions.
jaroslav@601:  */
jaroslav@601: package java.beans;
jaroslav@601: 
jaroslav@601: import java.util.ArrayList;
jaroslav@601: import java.util.Collections;
jaroslav@601: import java.util.EventListener;
jaroslav@601: import java.util.EventListenerProxy;
jaroslav@601: import java.util.HashMap;
jaroslav@601: import java.util.List;
jaroslav@601: import java.util.Map;
jaroslav@601: import java.util.Map.Entry;
jaroslav@601: import java.util.Set;
jaroslav@604: import org.apidesign.bck2brwsr.emul.lang.System;
jaroslav@601: 
jaroslav@601: /**
jaroslav@601:  * This is an abstract class that provides base functionality
jaroslav@601:  * for the {@link PropertyChangeSupport PropertyChangeSupport} class
jaroslav@601:  * and the {@link VetoableChangeSupport VetoableChangeSupport} class.
jaroslav@601:  *
jaroslav@601:  * @see PropertyChangeListenerMap
jaroslav@601:  * @see VetoableChangeListenerMap
jaroslav@601:  *
jaroslav@601:  * @author Sergey A. Malenkov
jaroslav@601:  */
jaroslav@601: abstract class ChangeListenerMap<L extends EventListener> {
jaroslav@601:     private Map<String, L[]> map;
jaroslav@601: 
jaroslav@601:     /**
jaroslav@601:      * Creates an array of listeners.
jaroslav@601:      * This method can be optimized by using
jaroslav@601:      * the same instance of the empty array
jaroslav@601:      * when {@code length} is equal to {@code 0}.
jaroslav@601:      *
jaroslav@601:      * @param length  the array length
jaroslav@601:      * @return        an array with specified length
jaroslav@601:      */
jaroslav@601:     protected abstract L[] newArray(int length);
jaroslav@601: 
jaroslav@601:     /**
jaroslav@601:      * Creates a proxy listener for the specified property.
jaroslav@601:      *
jaroslav@601:      * @param name      the name of the property to listen on
jaroslav@601:      * @param listener  the listener to process events
jaroslav@601:      * @return          a proxy listener
jaroslav@601:      */
jaroslav@601:     protected abstract L newProxy(String name, L listener);
jaroslav@601: 
jaroslav@601:     /**
jaroslav@601:      * Adds a listener to the list of listeners for the specified property.
jaroslav@601:      * This listener is called as many times as it was added.
jaroslav@601:      *
jaroslav@601:      * @param name      the name of the property to listen on
jaroslav@601:      * @param listener  the listener to process events
jaroslav@601:      */
jaroslav@601:     public final synchronized void add(String name, L listener) {
jaroslav@601:         if (this.map == null) {
jaroslav@601:             this.map = new HashMap<String, L[]>();
jaroslav@601:         }
jaroslav@601:         L[] array = this.map.get(name);
jaroslav@601:         int size = (array != null)
jaroslav@601:                 ? array.length
jaroslav@601:                 : 0;
jaroslav@601: 
jaroslav@601:         L[] clone = newArray(size + 1);
jaroslav@601:         clone[size] = listener;
jaroslav@601:         if (array != null) {
jaroslav@601:             System.arraycopy(array, 0, clone, 0, size);
jaroslav@601:         }
jaroslav@601:         this.map.put(name, clone);
jaroslav@601:     }
jaroslav@601: 
jaroslav@601:     /**
jaroslav@601:      * Removes a listener from the list of listeners for the specified property.
jaroslav@601:      * If the listener was added more than once to the same event source,
jaroslav@601:      * this listener will be notified one less time after being removed.
jaroslav@601:      *
jaroslav@601:      * @param name      the name of the property to listen on
jaroslav@601:      * @param listener  the listener to process events
jaroslav@601:      */
jaroslav@601:     public final synchronized void remove(String name, L listener) {
jaroslav@601:         if (this.map != null) {
jaroslav@601:             L[] array = this.map.get(name);
jaroslav@601:             if (array != null) {
jaroslav@601:                 for (int i = 0; i < array.length; i++) {
jaroslav@601:                     if (listener.equals(array[i])) {
jaroslav@601:                         int size = array.length - 1;
jaroslav@601:                         if (size > 0) {
jaroslav@601:                             L[] clone = newArray(size);
jaroslav@601:                             System.arraycopy(array, 0, clone, 0, i);
jaroslav@601:                             System.arraycopy(array, i + 1, clone, i, size - i);
jaroslav@601:                             this.map.put(name, clone);
jaroslav@601:                         }
jaroslav@601:                         else {
jaroslav@601:                             this.map.remove(name);
jaroslav@601:                             if (this.map.isEmpty()) {
jaroslav@601:                                 this.map = null;
jaroslav@601:                             }
jaroslav@601:                         }
jaroslav@601:                         break;
jaroslav@601:                     }
jaroslav@601:                 }
jaroslav@601:             }
jaroslav@601:         }
jaroslav@601:     }
jaroslav@601: 
jaroslav@601:     /**
jaroslav@601:      * Returns the list of listeners for the specified property.
jaroslav@601:      *
jaroslav@601:      * @param name  the name of the property
jaroslav@601:      * @return      the corresponding list of listeners
jaroslav@601:      */
jaroslav@601:     public final synchronized L[] get(String name) {
jaroslav@601:         return (this.map != null)
jaroslav@601:                 ? this.map.get(name)
jaroslav@601:                 : null;
jaroslav@601:     }
jaroslav@601: 
jaroslav@601:     /**
jaroslav@601:      * Sets new list of listeners for the specified property.
jaroslav@601:      *
jaroslav@601:      * @param name       the name of the property
jaroslav@601:      * @param listeners  new list of listeners
jaroslav@601:      */
jaroslav@601:     public final void set(String name, L[] listeners) {
jaroslav@601:         if (listeners != null) {
jaroslav@601:             if (this.map == null) {
jaroslav@601:                 this.map = new HashMap<String, L[]>();
jaroslav@601:             }
jaroslav@601:             this.map.put(name, listeners);
jaroslav@601:         }
jaroslav@601:         else if (this.map != null) {
jaroslav@601:             this.map.remove(name);
jaroslav@601:             if (this.map.isEmpty()) {
jaroslav@601:                 this.map = null;
jaroslav@601:             }
jaroslav@601:         }
jaroslav@601:     }
jaroslav@601: 
jaroslav@601:     /**
jaroslav@601:      * Returns all listeners in the map.
jaroslav@601:      *
jaroslav@601:      * @return an array of all listeners
jaroslav@601:      */
jaroslav@601:     public final synchronized L[] getListeners() {
jaroslav@601:         if (this.map == null) {
jaroslav@601:             return newArray(0);
jaroslav@601:         }
jaroslav@601:         List<L> list = new ArrayList<L>();
jaroslav@601: 
jaroslav@601:         L[] listeners = this.map.get(null);
jaroslav@601:         if (listeners != null) {
jaroslav@601:             for (L listener : listeners) {
jaroslav@601:                 list.add(listener);
jaroslav@601:             }
jaroslav@601:         }
jaroslav@601:         for (Entry<String, L[]> entry : this.map.entrySet()) {
jaroslav@601:             String name = entry.getKey();
jaroslav@601:             if (name != null) {
jaroslav@601:                 for (L listener : entry.getValue()) {
jaroslav@601:                     list.add(newProxy(name, listener));
jaroslav@601:                 }
jaroslav@601:             }
jaroslav@601:         }
jaroslav@601:         return list.toArray(newArray(list.size()));
jaroslav@601:     }
jaroslav@601: 
jaroslav@601:     /**
jaroslav@601:      * Returns listeners that have been associated with the named property.
jaroslav@601:      *
jaroslav@601:      * @param name  the name of the property
jaroslav@601:      * @return an array of listeners for the named property
jaroslav@601:      */
jaroslav@601:     public final L[] getListeners(String name) {
jaroslav@601:         if (name != null) {
jaroslav@601:             L[] listeners = get(name);
jaroslav@601:             if (listeners != null) {
jaroslav@601:                 return listeners.clone();
jaroslav@601:             }
jaroslav@601:         }
jaroslav@601:         return newArray(0);
jaroslav@601:     }
jaroslav@601: 
jaroslav@601:     /**
jaroslav@601:      * Indicates whether the map contains
jaroslav@601:      * at least one listener to be notified.
jaroslav@601:      *
jaroslav@601:      * @param name  the name of the property
jaroslav@601:      * @return      {@code true} if at least one listener exists or
jaroslav@601:      *              {@code false} otherwise
jaroslav@601:      */
jaroslav@601:     public final synchronized boolean hasListeners(String name) {
jaroslav@601:         if (this.map == null) {
jaroslav@601:             return false;
jaroslav@601:         }
jaroslav@601:         L[] array = this.map.get(null);
jaroslav@601:         return (array != null) || ((name != null) && (null != this.map.get(name)));
jaroslav@601:     }
jaroslav@601: 
jaroslav@601:     /**
jaroslav@601:      * Returns a set of entries from the map.
jaroslav@601:      * Each entry is a pair consisted of the property name
jaroslav@601:      * and the corresponding list of listeners.
jaroslav@601:      *
jaroslav@601:      * @return a set of entries from the map
jaroslav@601:      */
jaroslav@601:     public final Set<Entry<String, L[]>> getEntries() {
jaroslav@601:         return (this.map != null)
jaroslav@601:                 ? this.map.entrySet()
jaroslav@601:                 : Collections.<Entry<String, L[]>>emptySet();
jaroslav@601:     }
jaroslav@601: 
jaroslav@601:     /**
jaroslav@601:      * Extracts a real listener from the proxy listener.
jaroslav@601:      * It is necessary because default proxy class is not serializable.
jaroslav@601:      *
jaroslav@601:      * @return a real listener
jaroslav@601:      */
jaroslav@601:     public final L extract(L listener) {
jaroslav@601:         while (listener instanceof EventListenerProxy) {
jaroslav@601:             EventListenerProxy<L> proxy = (EventListenerProxy<L>) listener;
jaroslav@601:             listener = proxy.getListener();
jaroslav@601:         }
jaroslav@601:         return listener;
jaroslav@601:     }
jaroslav@601: }