ptolemy.gui

Class UndoListener

java.lang.Object

ptolemy.gui.UndoListener

All Implemented Interfaces:

java.util.EventListener, javax.swing.event.UndoableEditListener

public class UndoListener
extends java.lang.Object
implements javax.swing.event.UndoableEditListener

An Undo/Redo listener for use with a JTextComponent.

A convenience constructor has been provided such that a caller can immediately have default shortcut key mappings for undo/redo actions on the text component

Since:

Ptolemy II 8.0

Version:

$Id$

Author:

Ben Leinfelder, ben leinfelder

Pt.AcceptedRating:

Red (cx)

Pt.ProposedRating:

Yellow (cxh)

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
protected class	UndoListener.RedoAction Perform the redo action.
protected class	UndoListener.UndoAction Perform the undo action.

Field Summary

Fields

Modifier and Type	Field and Description
protected javax.swing.undo.CompoundEdit	_compoundEdit A compound undo edit, or null if none is progress.
protected UndoListener.RedoAction	_redoAction The redo action.
protected javax.swing.undo.UndoManager	_undo The undo manager.
protected UndoListener.UndoAction	_undoAction The undo action.

Constructor Summary

Constructors

Constructor and Description
UndoListener() Construct an undo listener.
UndoListener(javax.swing.text.JTextComponent textArea) Construct an undo listener with default key mappings.

Method Summary

Modifier and Type	Method and Description
void	endCompoundEdit() End a compound edit.
void	redo() Perform a redo.
void	startCompoundEdit() Start a compound undo edit.
void	undo() Perform an undo.
void	undoableEditHappened(javax.swing.event.UndoableEditEvent event) Remember the edit and update the action state.

Methods inherited from class java.lang.Object

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

Field Detail

_redoAction

protected UndoListener.RedoAction _redoAction

The redo action.

_compoundEdit

protected javax.swing.undo.CompoundEdit _compoundEdit

A compound undo edit, or null if none is progress.

_undoAction

protected UndoListener.UndoAction _undoAction

The undo action.

_undo

protected javax.swing.undo.UndoManager _undo

The undo manager.

Constructor Detail

UndoListener

public UndoListener()

Construct an undo listener.

This constructor allows simple usage without setting up key mapping automatically (it is then the responsibilty of the caller to provide a mechanism for invoking the undo and redo actions.)

UndoListener

public UndoListener(javax.swing.text.JTextComponent textArea)

Construct an undo listener with default key mappings. The default key mappings invoke the undo and redo actions on textArea .

A typical usage pattern would be: JTextArea textArea = new JTextArea("testing"); textArea.getDocument().addUndoableEditListener(new UndoListener(textArea));

Parameters:

textArea - the text component that is being listened to and upon which undo/redo actions will be performed

Method Detail

endCompoundEdit

public void endCompoundEdit()

End a compound edit.

redo

public void redo()
          throws javax.swing.undo.CannotUndoException

Perform a redo.

Throws:

javax.swing.undo.CannotUndoException - Thrown if the redo cannot be done.

startCompoundEdit

public void startCompoundEdit()

Start a compound undo edit.

undo

public void undo()
          throws javax.swing.undo.CannotUndoException

Perform an undo.

Throws:

javax.swing.undo.CannotUndoException - Thrown if the redo cannot be done.

undoableEditHappened

public void undoableEditHappened(javax.swing.event.UndoableEditEvent event)

Remember the edit and update the action state.

Specified by:

undoableEditHappened in interface javax.swing.event.UndoableEditListener

Parameters:

event - The event that occurred.