org.wandora.topicmap.undowrapper

Class UndoBuffer

java.lang.Object

org.wandora.topicmap.undowrapper.UndoBuffer

public class UndoBuffer
extends java.lang.Object

UndoBuffer implements a storage for undo operations. Stored undo operations are grouped by a special marker-operations, also stored into the buffer. Marker-operation is added to the buffer after real operations. Undoing processes all undo-operations till next marker-operation.

UndoBuffer contains a redo-buffer also. Undoed operations are stored in redo-buffer until next operation is stored into the undo-buffer.

Undo-buffer's size is limited to MAX_BUFFER_SIZE operations. Undo-buffer removes marked sets of operations until the number of operations is below MAX_BUFFER_SIZE.

Author:

olli

Field Summary

Fields

Modifier and Type	Field and Description
static int	MAX_BUFFER_SIZE
private java.util.LinkedList<UndoOperation>	redobuffer
static boolean	SHOW_MESSAGE
static boolean	SKIP_EMPTY_OPERATIONS
static boolean	SKIP_OPERATIONS_TILL_NEXT_MARKER
private java.util.LinkedList<UndoOperation>	undobuffer

Constructor Summary

Constructors

Constructor and Description
UndoBuffer()

Method Summary

Modifier and Type	Method and Description
void	addMarker(java.lang.String label)
void	addMarker(java.lang.String undoLabel, java.lang.String redoLabel)
void	addOperation(UndoOperation op)
boolean	canRedo()
boolean	canUndo()
void	clear()
java.util.Collection<UndoOperation>	getOperations()
int	getRedoOperationNumber()
int	getUndoOperationNumber()
void	pruneOne()
void	redo()
private void	redoOne()
void	setSkipEmptyOperations(boolean s)
void	undo()
private void	undoOne()

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

SKIP_EMPTY_OPERATIONS

public static boolean SKIP_EMPTY_OPERATIONS

SHOW_MESSAGE

public static boolean SHOW_MESSAGE

MAX_BUFFER_SIZE

public static final int MAX_BUFFER_SIZE

See Also:

Constant Field Values

SKIP_OPERATIONS_TILL_NEXT_MARKER

public static boolean SKIP_OPERATIONS_TILL_NEXT_MARKER

undobuffer

private java.util.LinkedList<UndoOperation> undobuffer

redobuffer

private java.util.LinkedList<UndoOperation> redobuffer

Constructor Detail

UndoBuffer

public UndoBuffer()

Method Detail

clear

public void clear()

addOperation

public void addOperation(UndoOperation op)

pruneOne

public void pruneOne()

addMarker

public void addMarker(java.lang.String label)

addMarker

public void addMarker(java.lang.String undoLabel,
                      java.lang.String redoLabel)

undoOne

private void undoOne()
              throws UndoException

Throws:

UndoException

undo

public void undo()
          throws UndoException

Throws:

UndoException

redoOne

private void redoOne()
              throws UndoException

Throws:

UndoException

redo

public void redo()
          throws UndoException

Throws:

UndoException

canUndo

public boolean canUndo()

canRedo

public boolean canRedo()

getUndoOperationNumber

public int getUndoOperationNumber()

getRedoOperationNumber

public int getRedoOperationNumber()

setSkipEmptyOperations

public void setSkipEmptyOperations(boolean s)

getOperations

public java.util.Collection<UndoOperation> getOperations()