Timeline Nested Grouping and events

@Named("nestedGroupingTimelineView")
@ViewScoped
public class NestedGroupingTimelineView implements Serializable {

    private TimelineModel<Order, String> model;
    private TimelineEvent<Order> event; // current changed event
    private List<TimelineEvent<Order>> overlappedOrders; // all overlapped orders (events) to the changed order (event)
    private List<TimelineEvent<Order>> ordersToMerge; // selected orders (events) in the dialog which should be merged

    @PostConstruct
    protected void initialize() {

        model = new TimelineModel<>();

        // create nested groups
        TimelineGroup<String> group1 = new TimelineGroup<>("groupId1", "Truck Group Level 1", "groupId1", 1,
                Arrays.asList("groupId2", "id1", "id2", "id5", "id6"));
        TimelineGroup<String> group2 = new TimelineGroup<>("groupId2", "Truck Group Level 2", "groupId2", 2,
                Arrays.asList("id3", "id4"));
        TimelineGroup<String> group3 = new TimelineGroup<>("id1", "Truck 1", 2);
        TimelineGroup<String> group4 = new TimelineGroup<>("id2", "Truck 2", 2);
        TimelineGroup<String> group5 = new TimelineGroup<>("id3", "Truck 3", 3);
        TimelineGroup<String> group6 = new TimelineGroup<>("id4", "Truck 4", 3);
        TimelineGroup<String> group7 = new TimelineGroup<>("id5", "Truck 5", 2);
        TimelineGroup<String> group8 = new TimelineGroup<>("id6", "Truck 6", 2);
        TimelineGroup<String> group9 = new TimelineGroup<>("groupId3", "Truck Group Level 1", "groupId3", 1,
                Arrays.asList("id7", "id8", "id9"));
        TimelineGroup<String> group10 = new TimelineGroup<>("id7", "Truck 7", 2);
        TimelineGroup<String> group11 = new TimelineGroup<>("id8", "Truck 8", 2);
        TimelineGroup<String> group12 = new TimelineGroup<>("id9", "Truck 9", 2);

        // add nested groups to the model
        model.addGroup(group1);
        model.addGroup(group2);
        model.addGroup(group3);
        model.addGroup(group4);
        model.addGroup(group5);
        model.addGroup(group6);
        model.addGroup(group7);
        model.addGroup(group8);
        model.addGroup(group9);
        model.addGroup(group10);
        model.addGroup(group11);
        model.addGroup(group12);

        int orderNumber = 1;

        // iterate over groups
        for (int j = 1; j <= 12; j++) {
            LocalDateTime referenceDate = LocalDateTime.of(2015, Month.DECEMBER, 14, 8, 0);
            // iterate over events in the same group
            for (int i = 0; i < 6; i++) {
                LocalDateTime startDate = referenceDate.plusHours(3 * (Math.random() < 0.2 ? 1 : 0));

                LocalDateTime endDate = startDate.plusHours(2 + (int) Math.floor(Math.random() * 3));

                String imagePath = null;
                if (Math.random() < 0.25) {
                    imagePath = "images/timeline/box.png";
                }

                Order order = new Order(orderNumber, imagePath);
                model.add(TimelineEvent.<Order>builder()
                        .data(order)
                        .startDate(startDate)
                        .endDate(endDate)
                        .editable(true)
                        .group("id" + j)
                        .build());

                orderNumber++;
                referenceDate = endDate;
            }
        }
    }

    public TimelineModel<Order, String> getModel() {
        return model;
    }

    public void onChange(TimelineModificationEvent<Order> e) {
        // get changed event and update the model
        event = e.getTimelineEvent();
        model.update(event);

        // get overlapped events of the same group as for the changed event
        Set<TimelineEvent<Order>> overlappedEvents = model.getOverlappedEvents(event);

        if (overlappedEvents == null) {
            // nothing to merge
            return;
        }

        // list of orders which can be merged in the dialog
        overlappedOrders = new ArrayList<>(overlappedEvents);

        // no pre-selection
        ordersToMerge = null;

        // update the dialog's content and show the dialog
        PrimeFaces primefaces = PrimeFaces.current();
        primefaces.ajax().update("form:overlappedOrdersInner");
        primefaces.executeScript("PF('overlapEventsWdgt').show()");
    }

    public void onDelete(TimelineModificationEvent<Order> e) {
        // keep the model up-to-date
        model.delete(e.getTimelineEvent());
    }

    public void merge() {
        // merge orders and update UI if the user selected some orders to be merged
        if (ordersToMerge != null && !ordersToMerge.isEmpty()) {
            model.merge(event, ordersToMerge, TimelineUpdater.getCurrentInstance(":form:timeline"));
        }
        else {
            FacesMessage msg
                    = new FacesMessage(FacesMessage.SEVERITY_INFO, "Nothing to merge, please choose orders to be merged", null);
            FacesContext.getCurrentInstance().addMessage(null, msg);
        }

        overlappedOrders = null;
        ordersToMerge = null;
    }

    public int getSelectedOrder() {
        if (event == null) {
            return 0;
        }

        return event.getData().getNumber();
    }

    public List<TimelineEvent<Order>> getOverlappedOrders() {
        return overlappedOrders;
    }

    public List<TimelineEvent<Order>> getOrdersToMerge() {
        return ordersToMerge;
    }

    public void setOrdersToMerge(List<TimelineEvent<Order>> ordersToMerge) {
        this.ordersToMerge = ordersToMerge;
    }

}

public class Order implements java.io.Serializable {

    private final int number;
    private final String imagePath;

    public Order(int number, String imagePath) {
        this.number = number;
        this.imagePath = imagePath;
    }

    public int getNumber() {
        return number;
    }

    public String getImagePath() {
        return imagePath;
    }

    @Override
    public boolean equals(Object o) {
        if (this == o) {
            return true;
        }

        if (o == null || getClass() != o.getClass()) {
            return false;
        }

        Order order = (Order) o;

        return number == order.number;
    }

    @Override
    public int hashCode() {
        return number;
    }

}

@Named
@ApplicationScoped
@FacesConverter("org.primefaces.showcase.converter.OrderConverter")
public class OrderConverter implements Converter<TimelineEvent<Order>>, Serializable {

    private List<TimelineEvent<Order>> events;

    public OrderConverter() {
    }

    @Override
    public TimelineEvent<Order> getAsObject(FacesContext context, UIComponent component, String value) {
        if (value == null || value.isEmpty() || events == null || events.isEmpty()) {
            return null;
        }

        for (TimelineEvent<Order> event : events) {
            if (event.getData().getNumber() == Integer.valueOf(value)) {
                return event;
            }
        }

        return null;
    }

    @Override
    public String getAsString(FacesContext context, UIComponent component, TimelineEvent<Order> value) {
        if (value == null) {
            return null;
        }

        return String.valueOf(value.getData().getNumber());
    }

    public List<TimelineEvent<Order>> getEvents() {
        return events;
    }

    public void setEvents(List<TimelineEvent<Order>> events) {
        this.events = events;
    }
}