Undo (Big Faceless PDF Library 2.28.1)

java.lang.Object
- org.faceless.pdf2.viewer2.ViewerFeature
- - org.faceless.pdf2.viewer2.feature.Undo

All Implemented Interfaces:

ActionListener, EventListener, UndoableEditListener, DocumentPanelListener
```
public final class Undo
extends ViewerFeature
implements ActionListener, UndoableEditListener, DocumentPanelListener
```
This features adds an "Undo" and "Redo" entry to the Edit menu, which interfaces with the DocumentPanel.fireUndoableEditEvent(javax.swing.event.UndoableEditEvent) method to provide undo/redo across the Document. The name of this feature is Undo
This code is copyright the Big Faceless Organization. You're welcome to use, modify and distribute it in any form in your own projects, provided those projects continue to make use of the Big Faceless PDF library.

Since:

2.11.19

Field Summary

Fields
Modifier and Type	Field	Description
`static UndoableEdit`	`DISCARD`	An UndableEdit which can be passed into `DocumentPanel.fireUndoableEditEvent(javax.swing.event.UndoableEditEvent)` to clear the list.

Constructor Summary

Constructors
Constructor Description

Undo()

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`void`	`actionPerformed(ActionEvent e)`
`void`	`documentUpdated(DocumentPanelEvent event)`	Called when an `DocumentPanelEvent` is raised
`void`	`initialize(PDFViewer viewer)`	Called when the feature is first added to a viewer
`void`	`redo(DocumentPanel panel)`	Perform a redo action on the specified panel
`void`	`undo(DocumentPanel panel)`	Perform an undo action on the specified panel
`void`	`undoableEditHappened(UndoableEditEvent event)`

Methods inherited from class org.faceless.pdf2.viewer2.ViewerFeature
getAllEnabledFeatures, getAllFeatures, getCustomJavaScript, getFeatureProperty, getFeatureURLProperty, getName, isEnabledByDefault, setFeatureName, teardown, toString

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

- Field Detail
  - DISCARD
```
public static final UndoableEdit DISCARD
```
    An UndableEdit which can be passed into DocumentPanel.fireUndoableEditEvent(javax.swing.event.UndoableEditEvent) to clear the list. This should be done when the list needs to be cleared, due to an action on the Document that permanently changes the state of the PDF.
- Constructor Detail
  - Undo
```
public Undo()
```
- Method Detail
  - actionPerformed
```
public void actionPerformed(ActionEvent e)
```
    Specified by:
    
    actionPerformed in interface ActionListener
  - undo
```
public void undo(DocumentPanel panel)
```
    Perform an undo action on the specified panel
  - redo
```
public void redo(DocumentPanel panel)
```
    Perform a redo action on the specified panel
  - initialize
```
public void initialize(PDFViewer viewer)
```
    Description copied from class: ViewerFeature
    
    Called when the feature is first added to a viewer
    
    Overrides:
    
    initialize in class ViewerFeature
  - documentUpdated
```
public void documentUpdated(DocumentPanelEvent event)
```
    Description copied from interface: DocumentPanelListener
    
    Called when an DocumentPanelEvent is raised
    
    Specified by:
    
    documentUpdated in interface DocumentPanelListener
  - undoableEditHappened
```
public void undoableEditHappened(UndoableEditEvent event)
```
    Specified by:
    
    undoableEditHappened in interface UndoableEditListener