--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/jdk/src/java.desktop/share/classes/javax/swing/undo/UndoableEditSupport.java Sun Aug 17 15:54:13 2014 +0100
@@ -0,0 +1,183 @@
+/*
+ * Copyright (c) 1997, 2008, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation. Oracle designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Oracle in the LICENSE file that accompanied this code.
+ *
+ * This code 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
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+package javax.swing.undo;
+
+import javax.swing.event.*;
+import java.util.*;
+
+/**
+ * A support class used for managing <code>UndoableEdit</code> listeners.
+ *
+ * @author Ray Ryan
+ */
+public class UndoableEditSupport {
+ protected int updateLevel;
+ protected CompoundEdit compoundEdit;
+ protected Vector<UndoableEditListener> listeners;
+ protected Object realSource;
+
+ /**
+ * Constructs an <code>UndoableEditSupport</code> object.
+ */
+ public UndoableEditSupport() {
+ this(null);
+ }
+
+ /**
+ * Constructs an <code>UndoableEditSupport</code> object.
+ *
+ * @param r an <code>Object</code>
+ */
+ public UndoableEditSupport(Object r) {
+ realSource = r == null ? this : r;
+ updateLevel = 0;
+ compoundEdit = null;
+ listeners = new Vector<UndoableEditListener>();
+ }
+
+ /**
+ * Registers an <code>UndoableEditListener</code>.
+ * The listener is notified whenever an edit occurs which can be undone.
+ *
+ * @param l an <code>UndoableEditListener</code> object
+ * @see #removeUndoableEditListener
+ */
+ public synchronized void addUndoableEditListener(UndoableEditListener l) {
+ listeners.addElement(l);
+ }
+
+ /**
+ * Removes an <code>UndoableEditListener</code>.
+ *
+ * @param l the <code>UndoableEditListener</code> object to be removed
+ * @see #addUndoableEditListener
+ */
+ public synchronized void removeUndoableEditListener(UndoableEditListener l)
+ {
+ listeners.removeElement(l);
+ }
+
+ /**
+ * Returns an array of all the <code>UndoableEditListener</code>s added
+ * to this UndoableEditSupport with addUndoableEditListener().
+ *
+ * @return all of the <code>UndoableEditListener</code>s added or an empty
+ * array if no listeners have been added
+ * @since 1.4
+ */
+ public synchronized UndoableEditListener[] getUndoableEditListeners() {
+ return listeners.toArray(new UndoableEditListener[0]);
+ }
+
+ /**
+ * Called only from <code>postEdit</code> and <code>endUpdate</code>. Calls
+ * <code>undoableEditHappened</code> in all listeners. No synchronization
+ * is performed here, since the two calling methods are synchronized.
+ *
+ * @param e edit to be verified
+ */
+ protected void _postEdit(UndoableEdit e) {
+ UndoableEditEvent ev = new UndoableEditEvent(realSource, e);
+ @SuppressWarnings("unchecked")
+ Enumeration<UndoableEditListener> cursor =
+ ((Vector<UndoableEditListener>)listeners.clone()).elements();
+ while (cursor.hasMoreElements()) {
+ cursor.nextElement().undoableEditHappened(ev);
+ }
+ }
+
+ /**
+ * DEADLOCK WARNING: Calling this method may call
+ * <code>undoableEditHappened</code> in all listeners.
+ * It is unwise to call this method from one of its listeners.
+ *
+ * @param e edit to be posted
+ */
+ public synchronized void postEdit(UndoableEdit e) {
+ if (updateLevel == 0) {
+ _postEdit(e);
+ } else {
+ // PENDING(rjrjr) Throw an exception if this fails?
+ compoundEdit.addEdit(e);
+ }
+ }
+
+ /**
+ * Returns the update level value.
+ *
+ * @return an integer representing the update level
+ */
+ public int getUpdateLevel() {
+ return updateLevel;
+ }
+
+ /**
+ *
+ */
+ public synchronized void beginUpdate() {
+ if (updateLevel == 0) {
+ compoundEdit = createCompoundEdit();
+ }
+ updateLevel++;
+ }
+
+ /**
+ * Called only from <code>beginUpdate</code>.
+ * Exposed here for subclasses' use.
+ *
+ * @return new created {@code CompoundEdit} object
+ */
+ protected CompoundEdit createCompoundEdit() {
+ return new CompoundEdit();
+ }
+
+ /**
+ * DEADLOCK WARNING: Calling this method may call
+ * <code>undoableEditHappened</code> in all listeners.
+ * It is unwise to call this method from one of its listeners.
+ */
+ public synchronized void endUpdate() {
+ updateLevel--;
+ if (updateLevel == 0) {
+ compoundEdit.end();
+ _postEdit(compoundEdit);
+ compoundEdit = null;
+ }
+ }
+
+ /**
+ * Returns a string that displays and identifies this
+ * object's properties.
+ *
+ * @return a <code>String</code> representation of this object
+ */
+ public String toString() {
+ return super.toString() +
+ " updateLevel: " + updateLevel +
+ " listeners: " + listeners +
+ " compoundEdit: " + compoundEdit;
+ }
+}