oracle.adf.view.faces.bi.component.gantt

Class UndoManager

java.lang.Object

oracle.adf.view.faces.bi.component.gantt.UndoManager

All Implemented Interfaces:

java.io.Serializable

public class UndoManager
extends java.lang.Object
implements java.io.Serializable

The UndoManager manages a list of UndoableEdits. When an undoable action occurs (user presses the zoom-in button for example), an UndoableEdit representing the action is registered with the UndoManager. When a user presses the undo/redo button in the Gantt toolbar/menubar, the UndoManager is responsible for determining what the last/next UndoableEdit should be, so that the appropriate action can be taken to restore the state. Applications can provide their own UndoManager by extending this class and registering it on the Gantt instance using the setUndoManager method.

See Also:

Serialized Form

Field Summary

Fields

Modifier and Type	Field and Description
protected java.util.ArrayList<UndoableEdit>	m_edits

Constructor Summary

Constructors

Constructor and Description
UndoManager() Constructs a new instance of UndoManager.

Method Summary

Methods

Modifier and Type	Method and Description
void	addEdit(UndoableEdit edit) Adds an UndoableEdit to UndoManager.
boolean	canRedo() Determines whether redo is possible.
boolean	canUndo() Determines whether undo is possible.
UndoableEdit	current() Gets the current UndoableEdit
void	discardAllEdits() Removes all UndoableEdits.
protected int	getUndoLimits() Returns the maximum number of undo(s)/redo(s).
UndoableEdit	redo() Performs an redo action.
UndoableEdit	undo() Performs an undo action.

Methods inherited from class java.lang.Object

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

Field Detail

m_edits

protected java.util.ArrayList<UndoableEdit> m_edits

Constructor Detail

UndoManager

public UndoManager()

Constructs a new instance of UndoManager.

Method Detail

getUndoLimits

protected int getUndoLimits()

Returns the maximum number of undo(s)/redo(s).

Returns:

the maximum number of undo(s)/redo(s).

canUndo

public boolean canUndo()

Determines whether undo is possible.

Returns:

true if undo is possible, false otherwise.

canRedo

public boolean canRedo()

Determines whether redo is possible.

Returns:

true if redo is possible, false otherwise.

addEdit

public void addEdit(UndoableEdit edit)

Adds an UndoableEdit to UndoManager.

Parameters:

edit - the UndoableEdit to register with the UndoManager.

undo

public UndoableEdit undo()

Performs an undo action.

Returns:

the last UndoableEdit. null if no action needs to be taken.

redo

public UndoableEdit redo()

Performs an redo action.

Returns:

the next UndoableEdit. null if no action needs to be taken.

discardAllEdits

public void discardAllEdits()

Removes all UndoableEdits.

current

public UndoableEdit current()

Gets the current UndoableEdit

Returns:

the current UndoableEdit