edu.rice.cs.drjava.model.definitions
Class CompoundUndoManager

java.lang.Object
  javax.swing.undo.AbstractUndoableEdit
      javax.swing.undo.CompoundEdit
          javax.swing.undo.UndoManager
              edu.rice.cs.drjava.model.definitions.CompoundUndoManager

All Implemented Interfaces:

Serializable, EventListener, UndoableEditListener, UndoableEdit

public class CompoundUndoManager
extends UndoManager

Extended UndoManager with increased functionality. Can handle aggregating multiple edits into one for the purposes of undoing and redoing. It exposes editToBeUndone and editToBeRedone (under new names); they are protected methods in UndoManager. The public methods that involve composite state are synchronized, so this manager can be accessed outside of the event thread. The internal data structures _compoundEdits and _keys are not thread safe but they only accessed only by synchronized methods. The synchronization scheme (locking on this) follows UndoManager.

Version:

$Id: CompoundUndoManager.java 5361 2010-08-13 22:39:45Z mgricken $

See Also:

Serialized Form

Field Summary

private LinkedList<CompoundEdit>	_compoundEdits The compound edits we are storing.
private LinkedList<Integer>	_keys The keys for the CompoundEdits we are storing.
private int	_nextKey The next key to use for nested CompoundEdits.
private GlobalEventNotifier	_notifier Keeps track of the listeners to this undo manager.
private UndoableEdit	_savePoint The last edit that was performed before the last save.
private static int	counter
private int	id
(package private) static Log	LOG

Fields inherited from class javax.swing.undo.CompoundEdit

edits

Fields inherited from class javax.swing.undo.AbstractUndoableEdit

RedoName, UndoName

Constructor Summary

CompoundUndoManager(GlobalEventNotifier notifier)
Standard constructor.

Method Summary

boolean	_compoundEditInProgress() Returns whether or not a compound edit is in progress.
private void	_notifyUndoHappened() Helper method to notify the view that an undoable edit has occured.
boolean	addEdit(UndoableEdit e) Adds an edit.
boolean	canUndo() Returns true when a compound edit is in progress, or when there are valid stored undoable edits
void	documentSaved() Informs this undo manager that the document has been saved.
private void	endCompoundEdit() Ends the compoundEdit in progress if any.
void	endCompoundEdit(int key) Ends a compound edit.
void	endLastCompoundEdit() Ends the last compound edit that was created.
CompoundEdit	getLastCompoundEdit() Gets the last Compound Edit entered into the list.
UndoableEdit	getNextRedo() Gets the next redo.
UndoableEdit	getNextUndo() Gets the next undo.
String	getUndoPresentationName() Returns the presentation name for this undo, or delegates to super if none is available
boolean	isModified() Determines if the document is in the same undo state as it was when it was last saved.
void	redo() Overrides redo so that any compound edit in progress is ended before the redo is performed.
int	startCompoundEdit() Starts a compound edit.
String	toString()
void	undo() Undoes the last undoable edit, or compound edit created by the user.

Methods inherited from class javax.swing.undo.UndoManager

canRedo, canUndoOrRedo, discardAllEdits, editToBeRedone, editToBeUndone, end, getLimit, getRedoPresentationName, getUndoOrRedoPresentationName, redoTo, setLimit, trimEdits, trimForLimit, undoableEditHappened, undoOrRedo, undoTo

Methods inherited from class javax.swing.undo.CompoundEdit

die, getPresentationName, isInProgress, isSignificant, lastEdit

Methods inherited from class javax.swing.undo.AbstractUndoableEdit

replaceEdit

Methods inherited from class java.lang.Object

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

Field Detail

LOG

static Log LOG

counter

private static volatile int counter

id

private final int id

_compoundEdits

private final LinkedList<CompoundEdit> _compoundEdits

The compound edits we are storing. Not thread safe!

_keys

private final LinkedList<Integer> _keys

The keys for the CompoundEdits we are storing.

_nextKey

private volatile int _nextKey

The next key to use for nested CompoundEdits.

_savePoint

private volatile UndoableEdit _savePoint

The last edit that was performed before the last save.

_notifier

private final GlobalEventNotifier _notifier

Keeps track of the listeners to this undo manager.

Constructor Detail

CompoundUndoManager

public CompoundUndoManager(GlobalEventNotifier notifier)

Standard constructor.

Method Detail

startCompoundEdit

public int startCompoundEdit()

Starts a compound edit.

Returns:

the key for the compound edit

endLastCompoundEdit

public void endLastCompoundEdit()

Ends the last compound edit that was created. Used when a compound edit is created by the _undoListener in DefinitionsPane and the key is not known in DefinitionsDocument.

endCompoundEdit

public void endCompoundEdit(int key)

Ends a compound edit.

Parameters:

key - the key that was returned by startCompoundEdit()

getLastCompoundEdit

public CompoundEdit getLastCompoundEdit()

Gets the last Compound Edit entered into the list. Used in making a Compound edit for granular undo.

getNextUndo

public UndoableEdit getNextUndo()

Gets the next undo.

Returns:

the next undo

getNextRedo

public UndoableEdit getNextRedo()

Gets the next redo.

Returns:

the next redo

addEdit

public boolean addEdit(UndoableEdit e)

Adds an edit. Checks whether or not the current edit is a compound edit.

Specified by:

addEdit in interface UndoableEdit

Overrides:

addEdit in class UndoManager

Parameters:

e - the edit to be added

Returns:

true if the add is successful, false otherwise

_compoundEditInProgress

public boolean _compoundEditInProgress()

Returns whether or not a compound edit is in progress.

Returns:

true iff in progress

canUndo

public boolean canUndo()

Returns true when a compound edit is in progress, or when there are valid stored undoable edits

Specified by:

canUndo in interface UndoableEdit

Overrides:

canUndo in class UndoManager

Returns:

true iff undoing is possible

getUndoPresentationName

public String getUndoPresentationName()

Returns the presentation name for this undo, or delegates to super if none is available

Specified by:

getUndoPresentationName in interface UndoableEdit

Overrides:

getUndoPresentationName in class UndoManager

Returns:

the undo's presentation name

undo

public void undo()

Undoes the last undoable edit, or compound edit created by the user.

Specified by:

undo in interface UndoableEdit

Overrides:

undo in class UndoManager

redo

public void redo()

Overrides redo so that any compound edit in progress is ended before the redo is performed.

Specified by:

redo in interface UndoableEdit

Overrides:

redo in class UndoManager

_notifyUndoHappened

private void _notifyUndoHappened()

Helper method to notify the view that an undoable edit has occured. Note that lock on this is not held by the event thread (even if called from event thread) when notification happens.

endCompoundEdit

private void endCompoundEdit()

Ends the compoundEdit in progress if any. Used by undo(), redo(), documentSaved().

documentSaved

public void documentSaved()

Informs this undo manager that the document has been saved.

isModified

public boolean isModified()

Determines if the document is in the same undo state as it was when it was last saved.

Returns:

true iff all changes have been undone since the last save

toString

public String toString()

Overrides:

toString in class UndoManager