EDIT

import org.joda.time.DateTime;

import eu.etaxonomy.cdm.model.common.TimePeriod;

import eu.etaxonomy.cdm.vaadin.model.registration.RegistrationWorkingSet;

    private static final String LABEL_CAPTION_RELEASED = "Released";

    private static final int GRID_ROWS = 4;

    private Label releasedLabel = new Label();

    private String citationString;

    /**

    *

    */

   public RegistrationItem(RegistrationWorkingSet workingSet, AbstractView<?> parentView) {

       super(GRID_COLS, GRID_ROWS);

       init();

       setWorkingSet(workingSet, parentView);

   }

        typeStateLabel.setVisible(false);

        identifierLink.setVisible(false);

        openButton.setVisible(false);

        addComponent(citationSummaryLabel, 0, 1, 1, 3);

        publishedLabel.setVisible(false);

        releasedLabel.setStyleName(STYLE_LABEL_NOWRAP);

        releasedLabel.setContentMode(ContentMode.HTML);

        releasedLabel.setWidthUndefined();

        releasedLabel.setVisible(false);

        addComponent(releasedLabel, 2, 3);

        setComponentAlignment(releasedLabel, Alignment.BOTTOM_RIGHT);

    public void setItem(RegistrationDTO regDto, AbstractView<?> parentView){

        updateUI(regDto.getCitationString(), regDto.getCreated(), regDto.getDatePublished(), regDto.getMessages().size(), regDto);

    }

    public void setWorkingSet(RegistrationWorkingSet workingSet, AbstractView<?> parentView){

        this.parentView = parentView;

        updateUI(workingSet.getCitation(), workingSet.getCreated(), null, workingSet.messagesCount(), null);

    private void updateUI(String citationString,  DateTime created, TimePeriod datePublished,  int messagesCount, RegistrationDTO regDto) {

        StringBuffer labelMarkup = new StringBuffer();

        DateTime registrationDate = null;

        if(messagesCount > 0){

            getMessageButton().addClickListener(e -> {

                ShowDetailsEvent detailsEvent;

                if(regDto != null){

                    detailsEvent = new ShowDetailsEvent<RegistrationDTO, Integer>(

                            "messages");

                } else {

                    detailsEvent = new ShowDetailsEvent<RegistrationWorkingSet, Integer>(

                            e,

                            RegistrationWorkingSet.class,

                            null,

                            "messages");

                }

                publishEvent(detailsEvent);

                }

            );

        labelMarkup.append(citationString);

        if(regDto != null){

            labelMarkup.append("</br>").append(regDto.getSummary());

            typeStateLabel.setVisible(true);

            typeStateLabel.update(regDto.getRegistrationType(), regDto.getStatus());

            getIdentifierLink().setResource(new ExternalResource(regDto.getIdentifier()));

            //TODO make responsive and use specificIdentifier in case the space gets too narrow

            getIdentifierLink().setVisible(true);

            getIdentifierLink().setCaption(regDto.getIdentifier());

            // Buttons

            getOpenButton().setVisible(true);

            getOpenButton().addClickListener(e -> publishEvent(new NavigationEvent(

                    RegistrationWorkflowViewBean.NAME,

                    RegistrationWorkflowViewBean.ACTION_EDIT,

                    Integer.toString(regDto.getId())

                    )));

            registrationDate = regDto.getRegistrationDate();

        }

        getCitationSummaryLabel().setValue(labelMarkup.toString());

        updateDateLabels(created, datePublished, registrationDate);

    private void updateDateLabels(DateTime created, TimePeriod published, DateTime released) {

        getCreatedLabel().setValue("<span class=\"caption\">" + LABEL_CAPTION_CREATED + "</span>&nbsp;" + created.toString(ISODateTimeFormat.yearMonthDay()));

        if(published != null){

            getPublishedLabel().setVisible(true);

            StringBuffer sb = new StringBuffer();

            if(published.getStart() != null){

                sb.append(published.getStart().toString(ISODateTimeFormat.yearMonthDay()));

            }

            if(published.getEnd() != null){

                if(sb.length() > 0){

                    sb.append('-');

                    sb.append(published.getEnd().toString(ISODateTimeFormat.yearMonthDay()));

                }

            }

            getPublishedLabel().setValue("<span class=\"caption\">" + LABEL_CAPTION_PUBLISHED + "</span>&nbsp;" + sb.toString());

        if(released != null){

            getReleasedLabel().setVisible(true);

            getReleasedLabel().setValue("<span class=\"caption\">" + LABEL_CAPTION_RELEASED + "</span>&nbsp;" + released.toString(ISODateTimeFormat.yearMonthDay()));

        }

        // LABEL_CAPTION_RELEASED

    /**

     * @return

     */

    public Label getReleasedLabel() {

        return releasedLabel;

    }

    public Class<T> getEntityType() {

import org.joda.time.DateTime;

    private DateTime created = null;

                if(created == null || created.isAfter(regDto.getCreated())){

                    created = regDto.getCreated();

                }

    public DateTime getRegistrationDate() {

        return registrationDTOs.get(0).getRegistrationDate();

    }

    public DateTime getCreationDate() {

        return registrationDTOs.get(0).getCreated();

    }

    /**

     * The creation time stamp of a registration set always is

     * the creation DateTime of the oldest Registration contained

     * in the set.

     *

     * @return

     */

    public DateTime getCreated(){

        return created;

    }

    @EventListener(classes=ShowDetailsEvent.class, condition = "#event.entityType == T(eu.etaxonomy.cdm.vaadin.presenter.registration.RegistrationDTO)")

import eu.etaxonomy.cdm.model.common.TimePeriod;

    private TimePeriod datePublished;

                datePublished = citation.getDatePublished();

    /**

     * @return the registrationDate

     */

    public TimePeriod getDatePublished() {

        return datePublished;

    }

import java.util.ArrayList;

import java.util.List;

import eu.etaxonomy.cdm.vaadin.event.ShowDetailsEvent;

    @EventListener(classes=ShowDetailsEvent.class, condition = "#event.entityType == T(eu.etaxonomy.cdm.vaadin.model.registration.RegistrationWorkingSet)")

    public void onShowDetailsEvent(ShowDetailsEvent<?,?> event) { // WARNING don't use more specific generic type arguments

        List<String> messages = new ArrayList<>();

        for(RegistrationDTO dto : workingset.getRegistrationDTOs()){

            dto.getMessages().forEach(m -> messages.add(dto.getSummary() + ": " + m));

        }

        if(event.getProperty().equals("messages")){

            getView().openDetailsPopup("Messages", messages);

        }

    }

import java.util.List;

    /**

     * @param messages

     */

    void openDetailsPopup(String caption, List<String> messages);

import com.vaadin.server.Page;

import com.vaadin.ui.Notification;

import eu.etaxonomy.cdm.vaadin.component.registration.RegistrationItem;

        registration.addComponent(new RegistrationItem(workingset, this));

    /**

     * {@inheritDoc}

     */

    @Override

    public void openDetailsPopup(String caption, List<String> messages) {

        StringBuffer sb = new StringBuffer();

        sb.append("<div class=\"details-popup-content\">");

        messages.forEach(s -> sb.append(s).append("</br>"));

        sb.append("</div>");

        new Notification(caption, sb.toString(), Notification.Type.HUMANIZED_MESSAGE, true).show(Page.getCurrent());

    }