Implementing ProcessManager.add as an undoable operation.
- By Andreas Bäcker
- November 15, 2000
JAVA PRIMER
JCommands: A Flexible Undo Framework for Java
Andreas Bäcker
Listing 2. Implementing ProcessManager.add as an undoable operation.
class AddProcessDesc extends Command {
private ProcessDesc p;
private ProcessManager pm;
public AddProcessDesc(ProcessDesc p, ProcessManager pm) {
super("Add Process"); // Used for external representation
this.p = p;
this.pm = pm;
}
public void apply() { pm.add(p); }
public void undo() { pm.remove(p); }
}