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: UndoListener.java 57044 2010-01-27 22:41:05Z cxh $

Author:

Ben Leinfelder, ben leinfelder

Accepted Rating:

Red (cx)

Proposed Rating:

Yellow (cxh)

Nested Class Summary

protected class	UndoListener.RedoAction Peform the redo action.
protected class	UndoListener.UndoAction Perform the undo action.

Field Summary

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

UndoListener()
Construct an undo listener.

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

Method Summary

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

_undoAction

protected UndoListener.UndoAction _undoAction

The undo action.

_redoAction

protected UndoListener.RedoAction _redoAction

The redo 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

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.