/**
* Copyright (C) 2002-2012 The FreeCol Team
*
* This file is part of FreeCol.
*
* FreeCol 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.
*
* FreeCol 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.
*
* You should have received a copy of the GNU General Public License
* along with FreeCol. If not, see <http://www.gnu.org/licenses/>.
*/
package net.sf.freecol.common.model;
import javax.xml.stream.XMLStreamException;
import javax.xml.stream.XMLStreamReader;
import javax.xml.stream.XMLStreamWriter;
public class UnitTradeItem extends TradeItem {
/**
* The unit to change hands.
*/
private Unit unit;
/**
* Creates a new <code>UnitTradeItem</code> instance.
*
* @param game a <code>Game</code> value
* @param source a <code>Player</code> value
* @param destination a <code>Player</code> value
* @param unit an <code>Unit</code> value
*/
public UnitTradeItem(Game game, Player source, Player destination, Unit unit) {
super(game, "tradeItem.unit", source, destination);
this.unit = unit;
}
/**
* Creates a new <code>UnitTradeItem</code> instance.
*
* @param game a <code>Game</code> value
* @param in a <code>XMLStreamReader</code> value
*/
public UnitTradeItem(Game game, XMLStreamReader in) throws XMLStreamException {
super(game, in);
readFromXML(in);
}
/**
* Returns whether this TradeItem is valid.
*
* @return a <code>boolean</code> value
*/
public boolean isValid() {
return unit.getOwner() == getSource()
&& unit.getType().isAvailableTo(getDestination());
}
/**
* Returns whether this TradeItem must be unique. This is true for
* the StanceTradeItem and the GoldTradeItem, and false for all
* others.
*
* @return a <code>boolean</code> value
*/
public boolean isUnique() {
return false;
}
/**
* Get the unit to trade.
*
* @return The unit to trade.
*/
@Override
public Unit getUnit() {
return unit;
}
/**
* Set the unit to trade.
*
* @param unit The new <code>Unit</code> to trade.
*/
@Override
public void setUnit(Unit unit) {
this.unit = unit;
}
/**
* This method writes an XML-representation of this object to
* the given stream.
*
* @param out The target stream.
* @throws XMLStreamException if there are any problems writing
* to the stream.
*/
protected void toXMLImpl(XMLStreamWriter out) throws XMLStreamException {
super.toXML(out, getXMLElementTagName());
}
/**
* Write the attributes of this object to a stream.
*
* @param out The target stream.
* @throws XMLStreamException if there are any problems writing
* to the stream.
*/
@Override
protected void writeAttributes(XMLStreamWriter out)
throws XMLStreamException {
super.writeAttributes(out);
out.writeAttribute("unit", this.unit.getId());
}
/**
* Initialize this object from an XML-representation of this object.
*
* @param in The input stream with the XML.
* @throws XMLStreamException if a problem was encountered
* during parsing.
*/
public void readFromXML(XMLStreamReader in)
throws XMLStreamException {
super.readFromXML(in);
String unitId = in.getAttributeValue(null, "unit");
this.unit = game.getFreeColGameObject(unitId, Unit.class);
in.nextTag();
}
/**
* Gets the tag name of the root element representing this object.
*
* @return "unitTradeItem".
*/
public static String getXMLElementTagName() {
return "unitTradeItem";
}
}