Package com.mxgraph.util
Class mxUndoManager
java.lang.Object
com.mxgraph.util.mxEventSource
com.mxgraph.util.mxUndoManager
Implements an undo history.
This class fires the following events:
mxEvent.CLEAR fires after clear was executed. The event has no properties.
mxEvent.UNDO fires afer a significant edit was undone in undo. The
edit
property contains the mxUndoableEdit that was undone.
mxEvent.REDO fires afer a significant edit was redone in redo. The
edit
property contains the mxUndoableEdit that was redone.
mxEvent.ADD fires after an undoable edit was added to the history. The
edit
property contains the mxUndoableEdit that was added.-
Nested Class Summary
Nested classes/interfaces inherited from class com.mxgraph.util.mxEventSource
mxEventSource.mxIEventListener
-
Field Summary
FieldsModifier and TypeFieldDescriptionprotected List
<mxUndoableEdit> List that contains the steps of the command history.protected int
Index of the element to be added next.protected int
Maximum command history size.Fields inherited from class com.mxgraph.util.mxEventSource
eventListeners, eventsEnabled, eventSource
-
Constructor Summary
ConstructorsConstructorDescriptionConstructs a new undo manager with a default history size.mxUndoManager
(int size) Constructs a new undo manager for the specified size. -
Method Summary
Modifier and TypeMethodDescriptionboolean
canRedo()
Returns true if a redo is possible.boolean
canUndo()
Returns true if an undo is possible.void
clear()
Clears the command history.boolean
isEmpty()
void
redo()
Redoes the last change.protected void
trim()
Removes all pending steps after indexOfNextAdd from the history, invoking die on each edit.void
undo()
Undoes the last change.void
undoableEditHappened
(mxUndoableEdit undoableEdit) Method to be called to add new undoable edits to the history.Methods inherited from class com.mxgraph.util.mxEventSource
addListener, fireEvent, fireEvent, getEventSource, isEventsEnabled, removeListener, removeListener, setEventsEnabled, setEventSource
-
Field Details
-
size
protected int sizeMaximum command history size. 0 means unlimited history. Default is 100. -
history
List that contains the steps of the command history. -
indexOfNextAdd
protected int indexOfNextAddIndex of the element to be added next.
-
-
Constructor Details
-
mxUndoManager
public mxUndoManager()Constructs a new undo manager with a default history size. -
mxUndoManager
public mxUndoManager(int size) Constructs a new undo manager for the specified size.
-
-
Method Details
-
isEmpty
public boolean isEmpty() -
clear
public void clear()Clears the command history. -
canUndo
public boolean canUndo()Returns true if an undo is possible. -
undo
public void undo()Undoes the last change. -
canRedo
public boolean canRedo()Returns true if a redo is possible. -
redo
public void redo()Redoes the last change. -
undoableEditHappened
Method to be called to add new undoable edits to the history. -
trim
protected void trim()Removes all pending steps after indexOfNextAdd from the history, invoking die on each edit. This is called from undoableEditHappened.
-