org.eclipse.gef.commands
Class CompoundCommand

java.lang.Object
  org.eclipse.gef.commands.Command
      org.eclipse.gef.commands.CompoundCommand

Direct Known Subclasses:

ForwardUndoCompoundCommand

public class CompoundCommand
extends Command

An aggregation of multiple Commands. A CompoundCommand is executable if all of its contained Commands are executable, and it has at least one contained Command. The same is true for undo. When undo is called, the contained Commands are undone in the reverse order in which they were executed.

An empty CompoundCommand is not executable.

A CompoundCommand can be unwrapped. Unwrapping returns the simplest equivalent form of the CompoundCommand. So, if a CompoundCommand contains just one Command, that Command is returned.

Constructor Summary

CompoundCommand()
Constructs an empty CompoundCommand

CompoundCommand(String label)
Constructs an empty CompoundCommand with the specified label.

Method Summary

void	add(Command command) Adds the specified command if it is not null.
boolean	canExecute()
boolean	canUndo()
void	dispose() Disposes all contained Commands.
void	execute() Execute the command.For a compound command this means executing all of the commands that it contains.
Object[]	getChildren() This is useful when implementing ITreeContentProvider.getChildren(Object) to display the Command's nested structure.
List	getCommands()
String	getLabel()
boolean	isEmpty()
void	redo() Re-executes the Command.
int	size()
void	undo() Undoes the changes performed during execute().
Command	unwrap() Returns the simplest form of this Command that is equivalent.

Methods inherited from class org.eclipse.gef.commands.Command

chain, getDebugLabel, setDebugLabel, setLabel

Methods inherited from class java.lang.Object

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

Constructor Detail

CompoundCommand

public CompoundCommand()

Constructs an empty CompoundCommand

Since:

2.0

CompoundCommand

public CompoundCommand(String label)

Constructs an empty CompoundCommand with the specified label.

Parameters:

label - the label for the Command

Method Detail

add

public void add(Command command)

Adds the specified command if it is not null.

Parameters:

command - null or a Command

canExecute

public boolean canExecute()

Overrides:

canExecute in class Command

Returns:

true if the command can be executed

See Also:

Command.canExecute()

canUndo

public boolean canUndo()

Overrides:

canUndo in class Command

Returns:

true if the command can be undone. This method should only be called after execute() or redo() has been called.

See Also:

Command.canUndo()

dispose

public void dispose()

Disposes all contained Commands.

Overrides:

dispose in class Command

See Also:

Command.dispose()

execute

public void execute()

Execute the command.For a compound command this means executing all of the commands that it contains.

Overrides:

execute in class Command

getChildren

public Object[] getChildren()

This is useful when implementing ITreeContentProvider.getChildren(Object) to display the Command's nested structure.

Returns:

returns the Commands as an array of Objects.

getCommands

public List getCommands()

Returns:

the List of contained Commands

getLabel

public String getLabel()

Overrides:

getLabel in class Command

Returns:

a String used to describe this command to the User

See Also:

Command.getLabel()

isEmpty

public boolean isEmpty()

Returns:

true if the CompoundCommand is empty

redo

public void redo()

Description copied from class: Command

Re-executes the Command. This method should only be called after undo() has been called.

Overrides:

redo in class Command

See Also:

Command.redo()

size

public int size()

Returns:

the number of contained Commands

undo

public void undo()

Description copied from class: Command

Undoes the changes performed during execute(). This method should only be called after execute has been called, and only when canUndo() returns true.

Overrides:

undo in class Command

See Also:

Command.undo()

unwrap

public Command unwrap()

Returns the simplest form of this Command that is equivalent. This is useful for removing unnecessary nesting of Commands.

Returns:

the simplest form of this Command that is equivalent