Java tutorial
/******************************************************************************* * Copyright 2013 Thomas Letsch (contact@thomas-letsch.de) * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. ******************************************************************************/ package org.vaadin.addons.javaee.fields; import org.vaadin.addons.javaee.container.EntityContainer; import com.googlecode.javaeeutils.jpa.PersistentEntity; import com.vaadin.data.Property; import com.vaadin.ui.ComboBox; public class ManyToOneRelationField<ENTITY extends PersistentEntity> extends ComboBox { private static final long serialVersionUID = 1L; public ManyToOneRelationField() { } @SuppressWarnings("unchecked") public ENTITY getSelectedEntity() { if (getValue() != null && getValue() instanceof Long && getContainerDataSource() instanceof EntityContainer) { Long id = (Long) getValue(); EntityContainer<ENTITY> containerDataSource = (EntityContainer<ENTITY>) getContainerDataSource(); return containerDataSource.getItem(id).getEntity(); } return null; } @Override protected void setValue(Object newValue, boolean repaintIsNotNeeded) throws Property.ReadOnlyException { if (newValue instanceof PersistentEntity) { PersistentEntity persistentEntity = (PersistentEntity) newValue; super.setValue(persistentEntity.getId(), repaintIsNotNeeded); } else { super.setValue(newValue, repaintIsNotNeeded); } } }