The Undo/Redo action has thrown exceptions when no more items

were part of the stack. This exceptions are caught in the actionPerformed method
and logged to the console on Log Level "Debug" with a simple "beep" sound for the user
to notify an empty stack

VadereGui/src/org/vadere/gui/topographycreator/control/ActionRedo.java

 package org.vadere.gui.topographycreator.control;
 
+import org.apache.log4j.LogManager;
+import org.apache.log4j.Logger;
+import org.apache.log4j.Priority;
+
+import java.awt.*;
 import java.awt.event.ActionEvent;
 
-import javax.swing.AbstractAction;
-import javax.swing.ImageIcon;
+import javax.swing.*;
+import javax.swing.undo.CannotRedoException;
 import javax.swing.undo.UndoManager;
 
 /**
@@ -15,6 +20,7 @@ public class ActionRedo extends AbstractAction {
 	private static final long serialVersionUID = 4975524648404524891L;
 	private final UndoManager undoManager;
 	private final TopographyAction action;
+	private static Logger logger = LogManager.getLogger(ActionRedo.class);
 
 	public ActionRedo(final String name, final ImageIcon icon, final UndoManager undoManager,
 			final TopographyAction action) {
@@ -25,7 +31,12 @@ public class ActionRedo extends AbstractAction {
 
 	@Override
 	public void actionPerformed(ActionEvent arg0) {
-		undoManager.redo();
+		try {
+			undoManager.redo();
+		} catch (CannotRedoException e) {
+			logger.log(Priority.DEBUG, "Cannot redo! List of edits is empty!");
+			Toolkit.getDefaultToolkit().beep();
+		}
 		action.actionPerformed(arg0);
 	}
 }

VadereGui/src/org/vadere/gui/topographycreator/control/ActionUndo.java

 package org.vadere.gui.topographycreator.control;
 
+import org.apache.log4j.LogManager;
+import org.apache.log4j.Logger;
+import org.apache.log4j.Priority;
+
+import java.awt.*;
 import java.awt.event.ActionEvent;
 
-import javax.swing.AbstractAction;
-import javax.swing.ImageIcon;
+import javax.swing.*;
+import javax.swing.undo.CannotUndoException;
 import javax.swing.undo.UndoManager;
 
 /**
@@ -16,6 +21,7 @@ public class ActionUndo extends AbstractAction {
 	private static final long serialVersionUID = 6022031098257929748L;
 	private final UndoManager undoManager;
 	private final TopographyAction action;
+	private static Logger logger = LogManager.getLogger(ActionUndo.class);
 
 	public ActionUndo(final String name, final ImageIcon icon, UndoManager undoManager, final TopographyAction action) {
 		super(name, icon);
@@ -25,7 +31,13 @@ public class ActionUndo extends AbstractAction {
 
 	@Override
 	public void actionPerformed(ActionEvent arg0) {
-		undoManager.undo();
+		try {
+			undoManager.undo();
+		} catch (CannotUndoException e) {
+			logger.log(Priority.DEBUG, "Cannot undo! List of edits is empty!");
+			Toolkit.getDefaultToolkit().beep();
+		}
+
 		action.actionPerformed(arg0);
 	}