public abstract class Command
extends java.lang.Object
Command
.Constructor and Description |
---|
Command()
Constructs a Command with no label.
|
Command(java.lang.String label)
Constructs a Command with the specified label.
|
Modifier and Type | Method and Description |
---|---|
boolean |
canExecute() |
boolean |
canRedo() |
boolean |
canUndo() |
Command |
chain(Command command)
Returns a Command that represents the chaining of a specified Command to
this Command.
|
void |
dispose()
This is called to indicate that the
Command will not be used
again. |
void |
execute()
Executes the Command.
|
java.lang.String |
getDebugLabel() |
java.lang.String |
getLabel() |
void |
redo()
Re-executes the Command.
|
void |
setDebugLabel(java.lang.String label)
Sets the debug label for this command
|
void |
setLabel(java.lang.String label)
Sets the label used to describe this command to the User.
|
void |
undo()
Undoes the changes performed during
execute() . |
public Command()
public Command(java.lang.String label)
label
- the Command's labelpublic boolean canRedo()
true
if the command can be redone. This method
should only be called after undo()
has been called.public boolean canExecute()
true
if the command can be executedpublic boolean canUndo()
true
if the command can be undone. This method
should only be called after execute()
or
redo()
has been called.public Command chain(Command command)
execute()
after
this command has executed, and it will undo()
before this
Command is undone.command
- null
or the Command being chainedpublic void dispose()
Command
will not be used
again. The Command may be in any state (executed, undone or redone) when
dispose is called. The Command should not be referenced in any way after
it has been disposed.public void execute()
public java.lang.String getDebugLabel()
public java.lang.String getLabel()
public void redo()
undo()
has been called.public void setDebugLabel(java.lang.String label)
label
- a description used for debugging onlypublic void setLabel(java.lang.String label)
label
- the labelpublic void undo()
execute()
. This method
should only be called after execute
has been called, and
only when canUndo()
returns true
.canUndo()
Copyright (c) IBM Corp. and others 2000, 2011. All Rights Reserved.