com.luciad.gui

LuciadLightspeedInterface ILcdUndoable

All Superinterfaces:

ILcdPropertyChangeSource

All Known Implementing Classes:

ALcdUndoable, TLcdCompositeUndoable

public interface ILcdUndoable
extends ILcdPropertyChangeSource

This interface describes objects that implement undo and redo behavior. When actions want to support a undo/redo mechanism, they should generate these kinds of objects and notify an ILcdUndoableListener that an undoable event has happened. This listener can than for instance provide actions to undo these events.

See Also:

TLcdUndoManager, TLcdUndoAction, TLcdRedoAction

Method Summary

Modifier and Type	Method and Description
boolean	addUndoable(ILcdUndoable aUndoable) Adds aUndoable to this ILcdUndoable.
boolean	canRedo() Returns whether or not this ILcdUndoable can be redone.
boolean	canUndo() Returns whether or not this ILcdUndoable can be undone.
void	die() Method that might be invoked to allow for cleanup tasks.
String	getDisplayName() Returns the display name of this ILcdUndoable.
String	getRedoDisplayName() Returns the redo display name of this ILcdUndoable.
String	getUndoDisplayName() Returns the undo display name of this ILcdUndoable.
boolean	isSignificant() Returns false if this ILcdUndoable is insignificant--for example one that maintains the user's selection, but does not change any model state.
void	redo() Redoes the operation represented by this ILcdUndoable.
void	undo() Undoes the operation represented by this ILcdUndoable.

Methods inherited from interface com.luciad.util.ILcdPropertyChangeSource

addPropertyChangeListener, removePropertyChangeListener

Method Detail

undo

void undo()
   throws TLcdCannotUndoRedoException

Undoes the operation represented by this ILcdUndoable.

Throws:

TLcdCannotUndoRedoException

redo

void redo()
   throws TLcdCannotUndoRedoException

Redoes the operation represented by this ILcdUndoable.

Throws:

TLcdCannotUndoRedoException

canUndo

boolean canUndo()

Returns whether or not this ILcdUndoable can be undone.

Returns:

Whether or not this ILcdUndoable can be undone.

canRedo

boolean canRedo()

Returns whether or not this ILcdUndoable can be redone.

Returns:

Whether or not this ILcdUndoable can be redone.

getDisplayName

String getDisplayName()

Returns the display name of this ILcdUndoable. It can for example be used for logging purposes.

getRedoDisplayName

String getRedoDisplayName()

Returns the redo display name of this ILcdUndoable. It can for example be used as the text of a menu item.

Returns:

The redo display name

getUndoDisplayName

String getUndoDisplayName()

Returns the undo display name of this ILcdUndoable. It can for example be used as the text of a menu item.

isSignificant

boolean isSignificant()

Returns false if this ILcdUndoable is insignificant--for example one that maintains the user's selection, but does not change any model state. This status can be used by an ILcdUndoableListener (like TLcdUndoManager) when deciding which ILcdUndoables to present to the user as Undo/Redo options, and which to perform as side effects of undoing or redoing other events.

Returns:

Whether or not this ILcdUndoable is significant.

die

void die()

Method that might be invoked to allow for cleanup tasks. For instance I/O streams could be closed here.

addUndoable

boolean addUndoable(ILcdUndoable aUndoable)

Adds aUndoable to this ILcdUndoable. If aUndoable cannot be added, this method should return false.

This mechanism allows you to collapse multiple ILcdUndoables into one. For instance when typing, you may or may not want every single keystroke to be separately undoable, but instead to undo a series of keystrokes that were within a certain time of each other.

Parameters:

aUndoable - The undoable to add to this ILcdUndoable.

Returns:

Whether or not aUndoable was accepted by this ILcdUndoable.