this.activityScheduler.setActivityState(new ActivityPresentationState(this.activityScheduler, this.activity));
this.activityScheduler.setActivityState(new ActivityPresentationState(this.activityScheduler, this.activity, true));
    public void previous()    {        switch(this.stepList.size())        {            // S' il n'y avait qu'une tape, on renvoie  la prsentation de l'activit             case 1: System.out.println("Methode PREVIOUS () du lastStep => ActivityPresentation");                    this.activityScheduler.setActivityState(new ActivityPresentationState(this.activityScheduler, this.activity));                    break;                      // S'il y avait deux tapes, on revient  la firstStep            case 2: System.out.println("Methode PREVIOUS () du lastStep => FirstStep");                    this.activityScheduler.setActivityState(new FirstStepState(this.activityScheduler, this.activity));                    break;            // Les autres cas, on remonte d'une tape                default:                       System.out.println("Mthode PREVIOUS() du lastStep-> MiddleStep");                    this.activityScheduler.setActivityState(new MiddleStepState(this.activityScheduler, this.activity, this.index-1));                    break;        }    }