PositionSerializer.java

package de.blau.android.util.mapbox.geojson.custom;

import java.lang.reflect.Type;

import com.google.gson.JsonArray;
import com.google.gson.JsonElement;
import com.google.gson.JsonPrimitive;
import com.google.gson.JsonSerializationContext;
import com.google.gson.JsonSerializer;

import de.blau.android.util.mapbox.models.Position;

/**
 * Required to handle the special case where the altitude might be a Double.NaN, which isn't a valid
 * double value as per JSON specification.
 *
 * @since 1.0.0
 */
public class PositionSerializer implements JsonSerializer<Position> {

  /**
   * Required to handle the special case where the altitude might be a Double.NaN, which isn't a
   * valid double value as per JSON specification.
   *
   * @param src       A {@link Position} defined by a longitude, latitude, and optionally, an
   *                  altitude.
   * @param typeOfSrc Common superinterface for all types in the Java.
   * @param context   Context for deserialization that is passed to a custom deserializer during
   *                  invocation of its {@link com.google.gson.JsonDeserializer#deserialize(JsonElement, Type,
   *                  com.google.gson.JsonDeserializationContext)} method.
   * @return a JsonArray containing the raw coordinates.
   * @since 1.0.0
   */
  @Override
  public JsonElement serialize(Position src, Type typeOfSrc, JsonSerializationContext context) {
    JsonArray rawCoordinates = new JsonArray();
    rawCoordinates.add(new JsonPrimitive(src.getLongitude()));
    rawCoordinates.add(new JsonPrimitive(src.getLatitude()));

    // Includes altitude
    if (src.hasAltitude()) {
      rawCoordinates.add(new JsonPrimitive(src.getAltitude()));
    }

    return rawCoordinates;
  }

}