org.eclipse.emf.common.command
Class BasicCommandStack

java.lang.Object
  |
  +--org.eclipse.emf.common.command.BasicCommandStack

All Implemented Interfaces:

CommandStack

Direct Known Subclasses:

PersistentCommandStack

public class BasicCommandStack

extends java.lang.Object

implements CommandStack

A basic and obvious implementation of an undoable stack of commands. See Command for more details about the command methods that this implementation uses.

Field Summary

protected java.util.List	commandList The list of commands.
protected java.util.Collection	listeners The CommandStackListeners.
protected Command	mostRecentCommand The command most recently executed, undone, or redone.
protected int	saveIndex The value of top when saveIsDone() is called.
protected int	top The current position within the list from which the next execute, undo, or redo, will be performed.

Constructor Summary

BasicCommandStack()
Creates a new empty instance.

Method Summary

void	addCommandStackListener(CommandStackListener listener) Adds a listener to the command stack, which will be notified whenever a command has been processed on the stack.
boolean	canRedo() Returns whether there are commands past the top of the stack that can be redone.
boolean	canUndo() Returns whether the top command on the stack can be undone.
void	execute(Command command) Clears any redoable commands not yet redone, adds the command, and then executes the command.
void	flush() Disposes all the commands in the stack.
Command	getMostRecentCommand() Returns the command most recently executed, undone, or redone.
Command	getRedoCommand() Returns the command that will be redone if redo() is called.
Command	getUndoCommand() Returns the command that will be undone if undo() is called.
boolean	isSaveNeeded() Returns whether the model has changes since saveIsDone() was call the last.
protected void	notifyListeners() This is called to ensure that CommandStackListener.commandStackChanged(java.util.EventObject) is called for each listener.
void	redo() Moves the top of the stack up, redoing the new top command.
void	removeCommandStackListener(CommandStackListener listener) Removes a listener from the command stack.
void	saveIsDone() Called after a save has been successfully performed.
void	undo() Moves the top of the stack down, undoing what was formerly the top command.

Methods inherited from class java.lang.Object

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

Field Detail

commandList

protected java.util.List commandList

The list of commands.

top

protected int top

The current position within the list from which the next execute, undo, or redo, will be performed.

mostRecentCommand

protected Command mostRecentCommand

The command most recently executed, undone, or redone.

listeners

protected java.util.Collection listeners

The CommandStackListeners.

saveIndex

protected int saveIndex

The value of top when saveIsDone() is called.

Constructor Detail

BasicCommandStack

public BasicCommandStack()

Creates a new empty instance.

Method Detail

execute

public void execute(Command command)

Description copied from interface: CommandStack

Clears any redoable commands not yet redone, adds the command, and then executes the command.

Specified by:

execute in interface CommandStack

Following copied from interface: org.eclipse.emf.common.command.CommandStack

Parameters:

command - the command to execute.

canUndo

public boolean canUndo()

Description copied from interface: CommandStack

Returns whether the top command on the stack can be undone.

Specified by:

canUndo in interface CommandStack

Following copied from interface: org.eclipse.emf.common.command.CommandStack

Returns:

whether the top command on the stack can be undone.

undo

public void undo()

Description copied from interface: CommandStack

Moves the top of the stack down, undoing what was formerly the top command.

Specified by:

undo in interface CommandStack

canRedo

public boolean canRedo()

Description copied from interface: CommandStack

Returns whether there are commands past the top of the stack that can be redone.

Specified by:

canRedo in interface CommandStack

Following copied from interface: org.eclipse.emf.common.command.CommandStack

Returns:

whether there are commands past the top of the stack that can be redone.

redo

public void redo()

Description copied from interface: CommandStack

Moves the top of the stack up, redoing the new top command.

Specified by:

redo in interface CommandStack

flush

public void flush()

Description copied from interface: CommandStack

Disposes all the commands in the stack.

Specified by:

flush in interface CommandStack

getUndoCommand

public Command getUndoCommand()

Description copied from interface: CommandStack

Returns the command that will be undone if CommandStack.undo() is called.

Specified by:

getUndoCommand in interface CommandStack

Following copied from interface: org.eclipse.emf.common.command.CommandStack

Returns:

the command that will be undone if CommandStack.undo() is called.

getRedoCommand

public Command getRedoCommand()

Description copied from interface: CommandStack

Returns the command that will be redone if CommandStack.redo() is called.

Specified by:

getRedoCommand in interface CommandStack

Following copied from interface: org.eclipse.emf.common.command.CommandStack

Returns:

the command that will be redone if CommandStack.redo() is called.

getMostRecentCommand

public Command getMostRecentCommand()

Description copied from interface: CommandStack

Returns the command most recently executed, undone, or redone.

Specified by:

getMostRecentCommand in interface CommandStack

Following copied from interface: org.eclipse.emf.common.command.CommandStack

Returns:

the command most recently executed, undone, or redone.

addCommandStackListener

public void addCommandStackListener(CommandStackListener listener)

Description copied from interface: CommandStack

Adds a listener to the command stack, which will be notified whenever a command has been processed on the stack.

Specified by:

addCommandStackListener in interface CommandStack

Following copied from interface: org.eclipse.emf.common.command.CommandStack

Parameters:

listener - the listener to add.

removeCommandStackListener

public void removeCommandStackListener(CommandStackListener listener)

Description copied from interface: CommandStack

Removes a listener from the command stack.

Specified by:

removeCommandStackListener in interface CommandStack

Following copied from interface: org.eclipse.emf.common.command.CommandStack

Parameters:

listener - the listener to remove.

notifyListeners

protected void notifyListeners()

This is called to ensure that CommandStackListener.commandStackChanged(java.util.EventObject) is called for each listener.

saveIsDone

public void saveIsDone()

Called after a save has been successfully performed.

isSaveNeeded

public boolean isSaveNeeded()

Returns whether the model has changes since saveIsDone() was call the last.

Returns:

whether the model has changes since saveIsDone was call the last.