/*
* Copyright (c) 1997, 2004, Oracle and/or its affiliates. All rights reserved.
* ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
*
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*/
package javax.swing.undo;
import java.util.*;
/**
* A concrete subclass of AbstractUndoableEdit, used to assemble little
* UndoableEdits into great big ones.
*
* @author Ray Ryan
*/
public class
CompoundEdit extends
AbstractUndoableEdit {
/**
* True if this edit has never received <code>end</code>.
*/
boolean
inProgress;
/**
* The collection of <code>UndoableEdit</code>s
* undone/redone en masse by this <code>CompoundEdit</code>.
*/
protected
Vector<
UndoableEdit>
edits;
public
CompoundEdit() {
super();
inProgress = true;
edits = new
Vector<
UndoableEdit>();
}
/**
* Sends <code>undo</code> to all contained
* <code>UndoableEdits</code> in the reverse of
* the order in which they were added.
*/
public void
undo() throws
CannotUndoException {
super.undo();
int
i =
edits.
size();
while (
i-- > 0) {
UndoableEdit e =
edits.
elementAt(
i);
e.
undo();
}
}
/**
* Sends <code>redo</code> to all contained
* <code>UndoableEdit</code>s in the order in
* which they were added.
*/
public void
redo() throws
CannotRedoException {
super.redo();
Enumeration cursor =
edits.
elements();
while (
cursor.
hasMoreElements()) {
((
UndoableEdit)
cursor.
nextElement()).
redo();
}
}
/**
* Returns the last <code>UndoableEdit</code> in
* <code>edits</code>, or <code>null</code>
* if <code>edits</code> is empty.
*/
protected
UndoableEdit lastEdit() {
int
count =
edits.
size();
if (
count > 0)
return
edits.
elementAt(
count-1);
else
return null;
}
/**
* Sends <code>die</code> to each subedit,
* in the reverse of the order that they were added.
*/
public void
die() {
int
size =
edits.
size();
for (int
i =
size-1;
i >= 0;
i--)
{
UndoableEdit e =
edits.
elementAt(
i);
// System.out.println("CompoundEdit(" + i + "): Discarding " +
// e.getUndoPresentationName());
e.
die();
}
super.die();
}
/**
* If this edit is <code>inProgress</code>,
* accepts <code>anEdit</code> and returns true.
*
* <p>The last edit added to this <code>CompoundEdit</code>
* is given a chance to <code>addEdit(anEdit)</code>.
* If it refuses (returns false), <code>anEdit</code> is
* given a chance to <code>replaceEdit</code> the last edit.
* If <code>anEdit</code> returns false here,
* it is added to <code>edits</code>.
*
* @param anEdit the edit to be added
* @return true if the edit is <code>inProgress</code>;
* otherwise returns false
*/
public boolean
addEdit(
UndoableEdit anEdit) {
if (!
inProgress) {
return false;
} else {
UndoableEdit last =
lastEdit();
// If this is the first subedit received, just add it.
// Otherwise, give the last one a chance to absorb the new
// one. If it won't, give the new one a chance to absorb
// the last one.
if (
last == null) {
edits.
addElement(
anEdit);
}
else if (!
last.
addEdit(
anEdit)) {
if (
anEdit.
replaceEdit(
last)) {
edits.
removeElementAt(
edits.
size()-1);
}
edits.
addElement(
anEdit);
}
return true;
}
}
/**
* Sets <code>inProgress</code> to false.
*
* @see #canUndo
* @see #canRedo
*/
public void
end() {
inProgress = false;
}
/**
* Returns false if <code>isInProgress</code> or if super
* returns false.
*
* @see #isInProgress
*/
public boolean
canUndo() {
return !
isInProgress() && super.canUndo();
}
/**
* Returns false if <code>isInProgress</code> or if super
* returns false.
*
* @see #isInProgress
*/
public boolean
canRedo() {
return !
isInProgress() && super.canRedo();
}
/**
* Returns true if this edit is in progress--that is, it has not
* received end. This generally means that edits are still being
* added to it.
*
* @see #end
*/
public boolean
isInProgress() {
return
inProgress;
}
/**
* Returns true if any of the <code>UndoableEdit</code>s
* in <code>edits</code> do.
* Returns false if they all return false.
*/
public boolean
isSignificant() {
Enumeration cursor =
edits.
elements();
while (
cursor.
hasMoreElements()) {
if (((
UndoableEdit)
cursor.
nextElement()).
isSignificant()) {
return true;
}
}
return false;
}
/**
* Returns <code>getPresentationName</code> from the
* last <code>UndoableEdit</code> added to
* <code>edits</code>. If <code>edits</code> is empty,
* calls super.
*/
public
String getPresentationName() {
UndoableEdit last =
lastEdit();
if (
last != null) {
return
last.
getPresentationName();
} else {
return super.getPresentationName();
}
}
/**
* Returns <code>getUndoPresentationName</code>
* from the last <code>UndoableEdit</code>
* added to <code>edits</code>.
* If <code>edits</code> is empty, calls super.
*/
public
String getUndoPresentationName() {
UndoableEdit last =
lastEdit();
if (
last != null) {
return
last.
getUndoPresentationName();
} else {
return super.getUndoPresentationName();
}
}
/**
* Returns <code>getRedoPresentationName</code>
* from the last <code>UndoableEdit</code>
* added to <code>edits</code>.
* If <code>edits</code> is empty, calls super.
*/
public
String getRedoPresentationName() {
UndoableEdit last =
lastEdit();
if (
last != null) {
return
last.
getRedoPresentationName();
} else {
return super.getRedoPresentationName();
}
}
/**
* Returns a string that displays and identifies this
* object's properties.
*
* @return a String representation of this object
*/
public
String toString()
{
return super.toString()
+ " inProgress: " +
inProgress
+ " edits: " +
edits;
}
}