org.eclipse.jface.text
Class DefaultUndoManager

java.lang.Object
  |
  +--org.eclipse.jface.text.DefaultUndoManager

All Implemented Interfaces:

IUndoManager

public class DefaultUndoManager

extends Object

implements IUndoManager

Standard implementation of IUndoManager. It registers with the connected text viewer as text listeners and logs all changes. It also monitors mouse and keyboard activities in order to partition the stream of text changes into undoable edit commands.

This class is not intended to be subclassed.

See Also:

ITextViewer, ITextListener, MouseListener, KeyListener

Constructor Summary

DefaultUndoManager(int undoLevel)
Creates a new undo manager who remembers the specified number of edit commands.

Method Summary

void	beginCompoundChange() Signals the undo manager that all subsequent changes until endCompoundChange is called are to be undone in one piece.
void	connect(ITextViewer textViewer) Connects this undo manager to the given text viewer.
void	disconnect() Disconnects this undo manager from its text viewer.
void	endCompoundChange() Signals the undo manager that the sequence of changes which started with beginCompoundChange has been finished.
void	redo() Repeats the most recently rolled back text change.
boolean	redoable() Returns whether at least one text change can be repeated.
void	reset() Resets the history of the undo manager.
void	setMaximalUndoLevel(int undoLevel) The given parameter determines the maximal length of the history remembered by the undo manager.
void	undo() Rolls back the most recently executed text change.
boolean	undoable() Returns whether at least one text change can be rolled back.

Methods inherited from class java.lang.Object

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

Constructor Detail

DefaultUndoManager

public DefaultUndoManager(int undoLevel)

Creates a new undo manager who remembers the specified number of edit commands.

Parameters:

undoLevel - the length of this manager's history

Method Detail

beginCompoundChange

public void beginCompoundChange()

Description copied from interface: IUndoManager

Signals the undo manager that all subsequent changes until endCompoundChange is called are to be undone in one piece.

Specified by:

beginCompoundChange in interface IUndoManager

endCompoundChange

public void endCompoundChange()

Description copied from interface: IUndoManager

Signals the undo manager that the sequence of changes which started with beginCompoundChange has been finished. All subsequent changes are considered to be individually undoable.

Specified by:

endCompoundChange in interface IUndoManager

setMaximalUndoLevel

public void setMaximalUndoLevel(int undoLevel)

Description copied from interface: IUndoManager

The given parameter determines the maximal length of the history remembered by the undo manager.

Specified by:

setMaximalUndoLevel in interface IUndoManager

Parameters:

undoLevel - the length of this undo manager's history

connect

public void connect(ITextViewer textViewer)

Description copied from interface: IUndoManager

Connects this undo manager to the given text viewer.

Specified by:

connect in interface IUndoManager

Parameters:

textViewer - the viewer the undo manager is connected to

disconnect

public void disconnect()

Description copied from interface: IUndoManager

Disconnects this undo manager from its text viewer. If this undo manager hasn't been connected before this operation has no effect.

Specified by:

disconnect in interface IUndoManager

reset

public void reset()

Description copied from interface: IUndoManager

Resets the history of the undo manager. After that call, there aren't any undoable or redoable text changes.

Specified by:

reset in interface IUndoManager

redoable

public boolean redoable()

Description copied from interface: IUndoManager

Returns whether at least one text change can be repeated. A text change can be repeated only if it was executed and rolled back.

Specified by:

redoable in interface IUndoManager

Returns:

true if at least on text change can be repeated

undoable

public boolean undoable()

Description copied from interface: IUndoManager

Returns whether at least one text change can be rolled back.

Specified by:

undoable in interface IUndoManager

Returns:

true if at least one text change can be rolled back

redo

public void redo()

Description copied from interface: IUndoManager

Repeats the most recently rolled back text change.

Specified by:

redo in interface IUndoManager

undo

public void undo()

Description copied from interface: IUndoManager

Rolls back the most recently executed text change.

Specified by:

undo in interface IUndoManager