clean up some run serialization stuff (especially icons!)

previously icons got their raw pixel data serialized to a massive
int array type structure in xml. now we serialize the entire ImageIcon
object to a base64 string, which is still quite a long string, but
fits nicely on one line instead of making the resulting xml feel hugely
bloated.

src/main/java/org/fenix/llanfair/Actions.java

@@ -345,6 +345,7 @@ final class Actions {
 	 */
 	private void xmlRead( InputStream in ) {
 		XStream xml = new XStream( new DomDriver() );
+		SerializationUtils.customize(xml);
 		master.setRun( ( Run ) xml.fromXML( in ) );
 	}
 
@@ -381,6 +382,7 @@ final class Actions {
 		BufferedOutputStream out = null;
 		try {
 			XStream xml = new XStream( new DomDriver() );
+			SerializationUtils.customize(xml);
 			out = new BufferedOutputStream( new FileOutputStream( file ) );
 			xml.toXML( master.getRun(), out );
 		} catch ( Exception ex ) {

src/main/java/org/fenix/llanfair/SerializationUtils.java

@@ -0,0 +1,78 @@
+package org.fenix.llanfair;
+
+import com.sun.xml.internal.ws.encoding.soap.SerializationException;
+import com.thoughtworks.xstream.XStream;
+import com.thoughtworks.xstream.converters.Converter;
+import com.thoughtworks.xstream.converters.MarshallingContext;
+import com.thoughtworks.xstream.converters.UnmarshallingContext;
+import com.thoughtworks.xstream.io.HierarchicalStreamReader;
+import com.thoughtworks.xstream.io.HierarchicalStreamWriter;
+import org.fenix.utils.config.Configuration;
+
+import javax.swing.*;
+import java.io.*;
+import java.util.Base64;
+
+public class SerializationUtils {
+	/**
+	 * Adds custom serialization settings, such as aliases and converters, to the given
+	 * XStream serialization object.
+	 * @param xml the XStream serialization object to add custom settings to
+	 */
+	public static void customize(XStream xml) {
+		xml.alias("Run", Run.class);
+		xml.alias("Config", Configuration.class);
+		xml.alias("Segment", Segment.class);
+
+		xml.registerConverter(new ImageIconConverter());
+	}
+
+	@SuppressWarnings("unchecked")
+	public static <T> T base64ToObject(String base64) throws IOException, ClassNotFoundException {
+		byte[] data = Base64.getDecoder().decode(base64);
+		ObjectInputStream ois = new ObjectInputStream(new ByteArrayInputStream(data));
+		T decoded = (T)ois.readObject();
+		ois.close();
+		return decoded;
+	}
+
+	public static String objectToBase64(Object obj) throws IOException {
+		ByteArrayOutputStream baos = new ByteArrayOutputStream();
+		ObjectOutputStream oos = new ObjectOutputStream(baos);
+		oos.writeObject(obj);
+		oos.close();
+		return Base64.getEncoder().encodeToString(baos.toByteArray());
+	}
+
+	public static class ImageIconConverter implements Converter {
+		@Override
+		public void marshal(Object source, HierarchicalStreamWriter writer, MarshallingContext context) {
+			ImageIcon icon = (ImageIcon)source;
+			writer.startNode("ImageIcon");
+			try {
+				writer.setValue(objectToBase64(icon));
+			} catch (IOException e) {
+				throw new SerializationException(e);
+			}
+			writer.endNode();
+		}
+
+		@Override
+		public Object unmarshal(HierarchicalStreamReader reader, UnmarshallingContext context) {
+			reader.moveDown();
+			ImageIcon icon;
+			try {
+				icon = base64ToObject(reader.getValue());
+			} catch (Exception e) {
+				throw new SerializationException(e);
+			}
+			reader.moveUp();
+			return icon;
+		}
+
+		@Override
+		public boolean canConvert(Class type) {
+			return type.equals(ImageIcon.class);
+		}
+	}
+}