myhw3.command

Class CommandHistoryObj

java.lang.Object

myhw3.command.CommandHistoryObj

All Implemented Interfaces:

CommandHistory

public final class CommandHistoryObj
extends java.lang.Object
implements CommandHistory

Field Summary

Fields

Modifier and Type	Field and Description
(package private) java.util.Stack<Command>	redoStack
(package private) java.util.Stack<Command>	undoStack

Constructor Summary

Constructors

Constructor and Description
CommandHistoryObj()

Method Summary

Modifier and Type	Method and Description
void	add(Command cmd) Add command undoable and clear redoable.
boolean	redo() Pop command from redoable, redo it, then push it onto undoable.
(package private) Command	topRedoCommand()
(package private) Command	topUndoCommand()
boolean	undo() Pop command from undoable, undo it, then push it onto redoable.

Methods inherited from class java.lang.Object

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

Field Detail

undoStack

java.util.Stack<Command> undoStack

redoStack

java.util.Stack<Command> redoStack

Constructor Detail

CommandHistoryObj

public CommandHistoryObj()

Method Detail

add

public void add(Command cmd)

Description copied from interface: CommandHistory

Add command undoable and clear redoable.

Specified by:

add in interface CommandHistory

Parameters:

cmd - the command to be run.

undo

public boolean undo()

Description copied from interface: CommandHistory

Pop command from undoable, undo it, then push it onto redoable.

Specified by:

undo in interface CommandHistory

redo

public boolean redo()

Description copied from interface: CommandHistory

Pop command from redoable, redo it, then push it onto undoable.

Specified by:

redo in interface CommandHistory

topUndoCommand

Command topUndoCommand()

topRedoCommand

Command topRedoCommand()