EventDataProvider.java

package de.flower.rmt.ui.page.events;

import de.flower.common.ui.inject.InjectorAwareObject;
import de.flower.rmt.model.db.entity.User;
import de.flower.rmt.model.db.entity.event.Event;
import de.flower.rmt.model.db.entity.event.QEvent;
import de.flower.rmt.service.IEventManager;
import de.flower.rmt.ui.model.EventModel;
import de.flower.rmt.ui.model.UserModel;
import org.apache.wicket.markup.repeater.data.IDataProvider;
import org.apache.wicket.model.IModel;
import org.apache.wicket.spring.injection.annot.SpringBean;

import java.util.Iterator;

/**
 * @author flowerrrr
 */
public class EventDataProvider extends InjectorAwareObject implements IDataProvider<Event> {

    @SpringBean
    private IEventManager eventManager;

    private int itemsPerPage;

    private Long size;

    private IModel<User> userModel;

    private Long nextEventId;

    public EventDataProvider(final int itemsPerPage) {
        this(itemsPerPage, null);
    }

    public EventDataProvider(final int itemsPerPage, final UserModel userModel) {
        this.itemsPerPage = itemsPerPage;
        this.userModel = userModel;
    }

    @Override
    public Iterator<? extends Event> iterator(final int first, final int count) {
        int pageNum = first / itemsPerPage;
        return eventManager.findAll(pageNum, itemsPerPage, getUser(), QEvent.event.team).iterator();
    }

    @Override
    public int size() {
        // method is called at least twice during rendering -> cache value
        if (size == null) {
            size = eventManager.getNumEventsByUser(getUser());
        }
        return size.intValue();
    }

    /**
     * Get the next upcoming event.
     */
    public boolean isNextEvent(Event event) {
        if (nextEventId == null) {
            Event nextEvent = eventManager.findNextEvent(getUser());
            nextEventId = (nextEvent == null) ? -1 : nextEvent.getId();
        }
        return event.getId().equals(nextEventId);
    }

    @Override
    public IModel<Event> model(final Event object) {
        return new EventModel<Event>(object);
    }

    @Override
    public void detach() {
        this.size = null;
        if (userModel != null) {
            this.userModel.detach();
        }
        this.nextEventId = null;
    }

    private User getUser() {
        return (userModel == null) ? null : userModel.getObject();
    }
}