/*
* @(#)CompoundEdit.java 1.25 04/05/05
*
* Copyright 2004 Sun Microsystems, Inc. All rights reserved.
* SUN PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
*/
package javax.swing.undo;
import java.util.*;
/**
* A concrete subclass of AbstractUndoableEdit, used to assemble little
* UndoableEdits into great big ones.
*
* @version 1.25 05/05/04
* @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 = (UndoableEdit)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 (UndoableEdit)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 = (UndoableEdit)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;
}
}
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