author | mcimadamore |
Thu, 01 Dec 2011 18:34:23 +0000 | |
changeset 11120 | f8576c769572 |
parent 5506 | 202f599c92aa |
child 12032 | 49ac5a2b1d5c |
permissions | -rw-r--r-- |
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/* |
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* Copyright (c) 2007, Oracle and/or its affiliates. All rights reserved. |
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* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
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* |
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* This code is free software; you can redistribute it and/or modify it |
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* under the terms of the GNU General Public License version 2 only, as |
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* published by the Free Software Foundation. Oracle designates this |
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* particular file as subject to the "Classpath" exception as provided |
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* by Oracle in the LICENSE file that accompanied this code. |
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* |
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* This code is distributed in the hope that it will be useful, but WITHOUT |
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* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
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* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
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* version 2 for more details (a copy is included in the LICENSE file that |
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* accompanied this code). |
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* |
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* You should have received a copy of the GNU General Public License version |
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* 2 along with this work; if not, write to the Free Software Foundation, |
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* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
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* |
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* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
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* or visit www.oracle.com if you need additional information or have any |
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* questions. |
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*/ |
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package java.beans; |
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import java.util.ArrayList; |
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import java.util.Collections; |
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import java.util.EventListener; |
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import java.util.EventListenerProxy; |
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import java.util.HashMap; |
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import java.util.List; |
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import java.util.Map; |
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import java.util.Map.Entry; |
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import java.util.Set; |
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/** |
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* This is an abstract class that provides base functionality |
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* for the {@link PropertyChangeSupport PropertyChangeSupport} class |
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* and the {@link VetoableChangeSupport VetoableChangeSupport} class. |
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* |
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* @see PropertyChangeListenerMap |
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* @see VetoableChangeListenerMap |
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* |
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* @author Sergey A. Malenkov |
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*/ |
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abstract class ChangeListenerMap<L extends EventListener> { |
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private Map<String, L[]> map; |
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/** |
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* Creates an array of listeners. |
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* This method can be optimized by using |
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* the same instance of the empty array |
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* when {@code length} is equal to {@code 0}. |
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* |
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* @param length the array length |
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* @return an array with specified length |
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*/ |
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protected abstract L[] newArray(int length); |
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/** |
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* Creates a proxy listener for the specified property. |
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* |
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* @param name the name of the property to listen on |
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* @param listener the listener to process events |
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* @return a proxy listener |
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*/ |
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protected abstract L newProxy(String name, L listener); |
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/** |
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* Adds a listener to the list of listeners for the specified property. |
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* This listener is called as many times as it was added. |
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* |
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* @param name the name of the property to listen on |
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* @param listener the listener to process events |
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*/ |
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public final synchronized void add(String name, L listener) { |
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if (this.map == null) { |
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this.map = new HashMap<>(); |
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} |
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L[] array = this.map.get(name); |
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int size = (array != null) |
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? array.length |
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: 0; |
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L[] clone = newArray(size + 1); |
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clone[size] = listener; |
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if (array != null) { |
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System.arraycopy(array, 0, clone, 0, size); |
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} |
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this.map.put(name, clone); |
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} |
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/** |
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* Removes a listener from the list of listeners for the specified property. |
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* If the listener was added more than once to the same event source, |
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* this listener will be notified one less time after being removed. |
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* |
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* @param name the name of the property to listen on |
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* @param listener the listener to process events |
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*/ |
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public final synchronized void remove(String name, L listener) { |
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if (this.map != null) { |
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L[] array = this.map.get(name); |
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if (array != null) { |
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for (int i = 0; i < array.length; i++) { |
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if (listener.equals(array[i])) { |
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int size = array.length - 1; |
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if (size > 0) { |
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L[] clone = newArray(size); |
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System.arraycopy(array, 0, clone, 0, i); |
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System.arraycopy(array, i + 1, clone, i, size - i); |
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this.map.put(name, clone); |
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} |
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else { |
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this.map.remove(name); |
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if (this.map.isEmpty()) { |
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this.map = null; |
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} |
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} |
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break; |
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} |
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} |
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} |
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} |
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} |
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/** |
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* Returns the list of listeners for the specified property. |
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* |
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* @param name the name of the property |
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* @return the corresponding list of listeners |
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*/ |
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public final synchronized L[] get(String name) { |
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return (this.map != null) |
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? this.map.get(name) |
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: null; |
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} |
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/** |
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* Sets new list of listeners for the specified property. |
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* |
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* @param name the name of the property |
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* @param listeners new list of listeners |
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*/ |
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public final void set(String name, L[] listeners) { |
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if (listeners != null) { |
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if (this.map == null) { |
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mcimadamore
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this.map = new HashMap<>(); |
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} |
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this.map.put(name, listeners); |
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} |
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else if (this.map != null) { |
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this.map.remove(name); |
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if (this.map.isEmpty()) { |
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this.map = null; |
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} |
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} |
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} |
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/** |
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* Returns all listeners in the map. |
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* |
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* @return an array of all listeners |
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*/ |
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public final synchronized L[] getListeners() { |
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if (this.map == null) { |
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return newArray(0); |
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} |
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7116954: Misc warnings in java.beans/java.beans.context
mcimadamore
parents:
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diff
changeset
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List<L> list = new ArrayList<>(); |
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L[] listeners = this.map.get(null); |
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if (listeners != null) { |
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for (L listener : listeners) { |
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list.add(listener); |
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} |
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} |
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for (Entry<String, L[]> entry : this.map.entrySet()) { |
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String name = entry.getKey(); |
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if (name != null) { |
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for (L listener : entry.getValue()) { |
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list.add(newProxy(name, listener)); |
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} |
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} |
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} |
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return list.toArray(newArray(list.size())); |
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} |
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/** |
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* Returns listeners that have been associated with the named property. |
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* |
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* @param name the name of the property |
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* @return an array of listeners for the named property |
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*/ |
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public final L[] getListeners(String name) { |
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if (name != null) { |
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L[] listeners = get(name); |
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if (listeners != null) { |
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return listeners.clone(); |
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} |
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} |
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return newArray(0); |
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} |
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/** |
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* Indicates whether the map contains |
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* at least one listener to be notified. |
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* |
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* @param name the name of the property |
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* @return {@code true} if at least one listener exists or |
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* {@code false} otherwise |
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*/ |
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public final synchronized boolean hasListeners(String name) { |
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if (this.map == null) { |
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return false; |
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} |
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L[] array = this.map.get(null); |
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return (array != null) || ((name != null) && (null != this.map.get(name))); |
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} |
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/** |
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* Returns a set of entries from the map. |
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* Each entry is a pair consisted of the property name |
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* and the corresponding list of listeners. |
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* |
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* @return a set of entries from the map |
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*/ |
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public final Set<Entry<String, L[]>> getEntries() { |
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return (this.map != null) |
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? this.map.entrySet() |
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: Collections.<Entry<String, L[]>>emptySet(); |
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} |
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/** |
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* Extracts a real listener from the proxy listener. |
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* It is necessary because default proxy class is not serializable. |
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* |
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* @return a real listener |
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*/ |
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public final L extract(L listener) { |
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while (listener instanceof EventListenerProxy) { |
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11120
f8576c769572
7116954: Misc warnings in java.beans/java.beans.context
mcimadamore
parents:
5506
diff
changeset
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@SuppressWarnings("unchecked") |
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EventListenerProxy<L> proxy = (EventListenerProxy<L>) listener; |
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listener = proxy.getListener(); |
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} |
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return listener; |
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} |
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} |