SingleSelectConverter.java

/**
 * Copyright 2009-2013 Oy Vaadin Ltd
 *
 * 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 com.vaadin.addon.jpacontainer.fieldfactory;

import java.util.Locale;

import com.vaadin.addon.jpacontainer.EntityContainer;
import com.vaadin.v7.data.util.converter.Converter;
import com.vaadin.v7.ui.AbstractSelect;

public class SingleSelectConverter<T> implements Converter<Object, T> {

    private final AbstractSelect select;

    public SingleSelectConverter(AbstractSelect select) {
        this.select = select;
    }

    @SuppressWarnings("unchecked")
    private EntityContainer<T> getContainer() {
        return (EntityContainer<T>) select.getContainerDataSource();
    }

    @Override
    public T convertToModel(Object value, Class<? extends T> targetType,
            Locale locale)
            throws com.vaadin.v7.data.util.converter.Converter.ConversionException {
        if (value != select.getNullSelectionItemId()) {
            return getContainer().getEntityProvider().getEntity(getContainer(),
                    value);
        } else {
            return null;
        }
    }

    @Override
    public Object convertToPresentation(T value,
            Class<? extends Object> targetType, Locale locale)
            throws com.vaadin.v7.data.util.converter.Converter.ConversionException {
        if (value != null) {
            return getContainer().getEntityProvider().getIdentifier(value);
        }
        return select.getNullSelectionItemId();
    }

    @Override
    public Class<T> getModelType() {
        return getContainer().getEntityClass();
    }

    @Override
    public Class<Object> getPresentationType() {
        return Object.class;
    }

}