dk.rode.thesis.factorymethod
Class SequenceCommandCreator<E>

java.lang.Object
  dk.rode.thesis.factorymethod.CommandCreator<E,Sequence.State>
      dk.rode.thesis.factorymethod.SequenceCommandCreator<E>

Type Parameters:

E - The type of values delivered by created commands (and thus sequences).

Direct Known Subclasses:

EvilSequenceCommandCreator, ReversibleSequenceCommandCreator

@Participant(value="ConcreteCreator")
public class SequenceCommandCreator<E>
extends CommandCreator<E,Sequence.State>

A standard command creator creates new commands based on sequence states as tokens.

This creator can create the following commands based on the supplied internal sequence state:

• null: a NullCommand is returned.

• Sequence.State.NORMAL: creates a new NextCommand instance.

• Sequence.State.RESET: creates a new ResetCommand instance.

• Otherwise: a command created by CommandCreator.createDefault(Sequence) is returned, if not null; if null, a null command is returned.

A sequence command creator is stateless and thread-safe.

Author:

Gunni Rode / rode.dk

Constructor Summary

SequenceCommandCreator()
No-arg constructor.

Method Summary

protected Command<E>

create(Sequence<E> sequence, Sequence.State state) Factory method to create a new command of the type specified by the token supplied as token.

Methods inherited from class dk.rode.thesis.factorymethod.CommandCreator

createDefault, equals, getCommand, hashCode, toString

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Constructor Detail

SequenceCommandCreator

public SequenceCommandCreator()

No-arg constructor.

Method Detail

create

protected Command<E> create(Sequence<E> sequence,
                            Sequence.State state)
                     throws Exception

Description copied from class: CommandCreator

Factory method to create a new command of the type specified by the token supplied as token.

The sequence set as the receiver is supplied as sequence.

Specified by:

create in class CommandCreator<E,Sequence.State>

Parameters:

sequence - The sequence; never null.

state - The token identifying the type of command to create; can be null.

Returns:

The corresponding command, or null if no such command could be created. If null is returned, a default (on null) command is returned by CommandCreator.getCommand(Sequence, Object).

Throws:

Exception - If the creation fails; if so, a default (or null) command will be returned by getCommand.

See Also:

CommandCreator.createDefault(Sequence)