/*
 * Copyright 2013 Nicolas Morel
 *
 * 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.github.nmorel.gwtjackson.client.ser;

import com.github.nmorel.gwtjackson.client.JsonSerializationContext;
import com.github.nmorel.gwtjackson.client.JsonSerializer;
import com.github.nmorel.gwtjackson.client.JsonSerializerParameters;
import com.github.nmorel.gwtjackson.client.stream.JsonWriter;

/**
 * Default {@link JsonSerializer} implementation for {@link Void}.
 *
 * @author Nicolas Morel
 * @version $Id: $
 */
public class VoidJsonSerializer extends JsonSerializer<Void> {

    private static final VoidJsonSerializer INSTANCE = new VoidJsonSerializer();

    /**
     * <p>getInstance</p>
     *
     * @return an instance of {@link VoidJsonSerializer}
     */
    public static VoidJsonSerializer getInstance() {
        return INSTANCE;
    }

    private VoidJsonSerializer() { }

    /** {@inheritDoc} */
    @Override
    protected void serializeNullValue( JsonWriter writer, JsonSerializationContext ctx, JsonSerializerParameters params ) {
        if ( writer.getSerializeNulls() ) {
            writer.setSerializeNulls( false );
            writer.nullValue();
            writer.setSerializeNulls( true );
        } else {
            writer.nullValue();
        }
    }

    /** {@inheritDoc} */
    @Override
    public void doSerialize( JsonWriter writer, Void value, JsonSerializationContext ctx, JsonSerializerParameters params ) {
        // we should never be here, the null value is already handled and it's the only possible value for Void
    }
}