/*
* MegaMek - Copyright (C) 2003 Ben Mazur (bmazur@sev.org)
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by the Free
* Software Foundation; either version 2 of the License, or (at your option)
* any later version.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
* or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* for more details.
*/
package megamek.common.xml;
import gd.xml.tiny.ParsedXML;
import java.io.IOException;
import java.io.Writer;
import java.util.Enumeration;
import megamek.common.Hex;
import megamek.common.IGame;
import megamek.common.IHex;
import megamek.common.ITerrain;
import megamek.common.ITerrainFactory;
import megamek.common.Terrains;
import megamek.common.util.StringUtil;
/**
* Objects of this class can encode a <code>Hex</code> object as XML into an
* output writer and decode one from a parsed XML node. It is used when saving
* games into a version- neutral format.
*
* @author James Damour <suvarov454@users.sourceforge.net>
*/
public class HexEncoder {
/**
* Encode a <code>Hex</code> object to an output writer.
*
* @param hex - the <code>Hex</code> to be encoded. This value must not be
* <code>null</code>.
* @param out - the <code>Writer</code> that will receive the XML. This
* value must not be <code>null</code>.
* @throws <code>IllegalArgumentException</code> if the node is
* <code>null</code>.
* @throws <code>IOException</code> if there's any error on write.
*/
public static void encode(IHex hex, Writer out) throws IOException {
ITerrain terrain = null;
int loop = 0;
// First, validate our input.
if (null == hex) {
throw new IllegalArgumentException("The hex is null.");
}
if (null == out) {
throw new IllegalArgumentException("The writer is null.");
}
// Start the XML stream for this hex
out.write("<hex version=\"1.0\" >");
// OK, so elevation and theme aren't *strictly speaking* part of
// terrain, but it's convenient to store this info here. Cope.
out.write("<terrains count=\"");
out.write(Integer.toString(hex.terrainsPresent()));
out.write("\" elevation=\"");
out.write(Integer.toString(hex.getElevation()));
if (null != hex.getTheme()) {
out.write("\" theme=\"");
out.write(hex.getTheme());
}
out.write("\" >");
for (loop = 0; loop < Terrains.SIZE; loop++) {
// If the hex has this kind of terrain, encode it.
if (hex.containsTerrain(loop)) {
terrain = hex.getTerrain(loop);
out.write("<terrain type=\"");
out.write(Integer.toString(terrain.getType()));
out.write("\" level=\"");
out.write(Integer.toString(terrain.getLevel()));
out.write("\" exits=\"");
out.write(Integer.toString(terrain.getExits()));
out.write("\" exitsSpecified=\"");
out.write(terrain.hasExitsSpecified() ? "true" : "false");
out.write("\" />");
}
}
out.write("</terrains>");
out.write("</hex>");
}
/**
* Decode a <code>Hex</code> object from the passed node.
*
* @param node - the <code>ParsedXML</code> node for this object. This
* value must not be <code>null</code>.
* @param game - the <code>IGame</code> the decoded object belongs to.
* @return the <code>Hex</code> object based on the node.
* @throws <code>IllegalArgumentException</code> if the node is
* <code>null</code>.
* @throws <code>IllegalStateException</code> if the node does not contain
* a valid <code>Hex</code>.
*/
public static IHex decode(ParsedXML node, IGame game) {
String attrStr = null;
int attrVal = 0;
IHex retVal = null;
ITerrainFactory f = Terrains.getTerrainFactory();
// Did we get a null node?
if (null == node) {
throw new IllegalArgumentException("The hex is null.");
}
// Make sure that the node is for a Hex object.
if (!node.getName().equals("hex")) {
throw new IllegalStateException("Not passed a hex node.");
}
// TODO : perform version checking.
// Find the terrains node.
Enumeration<?> children = node.elements();
while (children.hasMoreElements()) {
ParsedXML child = (ParsedXML) children.nextElement();
if (child.getName().equals("terrains")) {
// There should be only one terrains node.
if (null != retVal) {
throw new IllegalStateException(
"More than one 'terrains' node in a hex node.");
}
// Create an array to hold all the terrains.
ITerrain[] terrains = new ITerrain[Terrains.SIZE];
// Walk through the subnodes, parsing out terrain nodes.
Enumeration<?> subnodes = child.elements();
while (subnodes.hasMoreElements()) {
// Is this a "terrain" node?
ParsedXML subnode = (ParsedXML) subnodes.nextElement();
if (subnode.getName().equals("terrain")) {
// Try to parse the terrain node.
try {
final int type = Integer.parseInt(subnode
.getAttribute("type"));
final boolean exitsSpecified = StringUtil
.parseBoolean(subnode
.getAttribute("exitsSpecified"));
final int level = Integer.parseInt(subnode
.getAttribute("level"));
final int exits = Integer.parseInt(subnode
.getAttribute("exits"));
terrains[type] = f.createTerrain(type, level,
exitsSpecified, exits);
} catch (Throwable thrown) {
throw new IllegalStateException(
"Couldn't parse a terrain from a hex node.");
}
} // End found-"terrain"-node
} // Look at the next subnode.
// Get the elevation of the hex.
attrStr = child.getAttribute("elevation");
if (null == attrStr) {
throw new IllegalStateException(
"Couldn't decode the terrains for a hex node.");
}
// Try to pull the elevation from the attribute string
try {
attrVal = Integer.parseInt(attrStr);
} catch (NumberFormatException exp) {
throw new IllegalStateException(
"Couldn't get an integer from " + attrStr);
}
// Get the theme of the hex (if any).
attrStr = child.getAttribute("theme");
// Construct the hex.
retVal = new Hex(attrVal, terrains, attrStr);
} // End found-"terrains"-node
} // Look at the next child.
// Return the hex for this node.
return retVal;
}
}