Package com.levigo.jadice.web.client.undo

Class MementoBasedUndoableEdit

java.lang.Object

com.levigo.jadice.web.client.undo.AbstractUndoableEdit

com.levigo.jadice.web.client.undo.MementoBasedUndoableEdit

All Implemented Interfaces:

UndoableEdit

public class MementoBasedUndoableEdit
extends AbstractUndoableEdit

An UndoableEdit using two Memento, one from before and one after the edit.

Constructor Summary

Constructors

Constructor	Description
MementoBasedUndoableEdit(String description, Object mergeKey, org.jadice.util.base.Memento before, org.jadice.util.base.Memento after)	Create a memento-based undoable edit from the given menentos and the description of the edit.

Method Summary

Modifier and Type	Method	Description
String	getDescription()	Return a presentation name fragment suitable for use both in an "undo something" and "redo something" style phrase.
void	redo()	Re-do the edit.
boolean	tryMergeInto(UndoableEdit anEdit)	Determine whether the given edit can be merged into this edit.
void	undo()	Undo the edit.
protected void	updateAfterState(MementoBasedUndoableEdit newEdit)

Methods inherited from class com.levigo.jadice.web.client.undo.AbstractUndoableEdit

getRedoDescription, getUndoDescription

Methods inherited from class java.lang.Object

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

Methods inherited from interface com.levigo.jadice.web.client.undo.UndoableEdit

canRedo, canUndo, discard

Constructor Details

MementoBasedUndoableEdit

public MementoBasedUndoableEdit(String description,
 Object mergeKey,
 org.jadice.util.base.Memento before,
 org.jadice.util.base.Memento after)

Create a memento-based undoable edit from the given menentos and the description of the edit. If non-null, the merge key is used to determine mergeability of two memento-based undoable edits: if they have the same merge key, as merge is performed by replacing the old after-memento with the new after-memento.

Parameters:

description - the description of the edit

mergeKey - the merge key or null if this edit can never be merged with another one

before - the before memento (used for undo)

after - the after memento (used for redo)

Method Details

tryMergeInto

public boolean tryMergeInto(UndoableEdit anEdit)

Description copied from interface: UndoableEdit

Determine whether the given edit can be merged into this edit. If it can, merge the edit and return true, otherwise do nothing and return false.

Parameters:

anEdit - the edit that should possible be merged into this edit

Returns:

true if this edit could be merged, false otherwise

getDescription

public String getDescription()

Description copied from class: AbstractUndoableEdit

Return a presentation name fragment suitable for use both in an "undo something" and "redo something" style phrase.

Specified by:

getDescription in class AbstractUndoableEdit

Returns:

a "something" fragment

undo

public void undo()
          throws CannotUndoException

Description copied from interface: UndoableEdit

Undo the edit.

Throws:

CannotUndoException - if this edit can not be undone

redo

public void redo()
          throws CannotRedoException

Description copied from interface: UndoableEdit

Re-do the edit.

Throws:

CannotRedoException - if this edit can not be re-done

updateAfterState

protected void updateAfterState(MementoBasedUndoableEdit newEdit)