EnumConverter.java

/**
 * <copyright>
 *
 * Copyright (c) 2011 Christian Kerl
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 * 
 * Contributors: 
 *   Christian Kerl - Initial API and implementation
 *
 * </copyright>
 */
package org.eclipselab.emf.ecore.protobuf.internal.conversion;

import org.eclipse.emf.common.util.Enumerator;
import org.eclipse.emf.ecore.EDataType;
import org.eclipse.emf.ecore.EEnum;
import org.eclipselab.emf.ecore.protobuf.conversion.FromProtoBufScalarConverter;
import org.eclipselab.emf.ecore.protobuf.conversion.ToProtoBufScalarConverter;

import com.google.protobuf.Descriptors.EnumDescriptor;
import com.google.protobuf.Descriptors.EnumValueDescriptor;
import com.google.protobuf.Descriptors.FieldDescriptor;
import com.google.protobuf.Descriptors.FieldDescriptor.Type;


/**
 * EnumConverter provides {@link FromProtoBufScalarConverter} and
 * {@link ToProtoBufScalarConverter} implementations for arbitrary
 * enums. 
 * 
 * @author Christian Kerl
 */
public class EnumConverter
{

  public static class FromProtoBuf extends FromProtoBufScalarConverter
  {
    @Override
    public boolean supports(FieldDescriptor sourceType, EDataType targetType)
    {
      return sourceType.getType() == Type.ENUM && targetType instanceof EEnum;
    }

    @Override
    public Object convert(FieldDescriptor sourceType, Object source, EDataType targetType)
    {
      return doConvert((EnumValueDescriptor)source, (EEnum)targetType);
    }

    private Object doConvert(EnumValueDescriptor source, EEnum targetType)
    {
      return targetType.getEEnumLiteral(source.getName()).getInstance();
    }
  }

  public static class ToProtoBuf extends ToProtoBufScalarConverter
  {
    @Override
    public boolean supports(EDataType sourceType, FieldDescriptor targetType)
    {
      return sourceType instanceof EEnum && targetType.getType() == Type.ENUM;
    }

    @Override
    public Object convert(EDataType sourceType, Object source, FieldDescriptor targetType)
    {
      return doConvert((Enumerator)source, targetType.getEnumType());
    }

    private Object doConvert(Enumerator source, EnumDescriptor targetType)
    {
      return targetType.findValueByName(source.getName());
    }
  }
}