freecol/src/net/sf/freecol/common/model/mission/Mission.java

95 lines
2.6 KiB
Java

/**
* Copyright (C) 2002-2022 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
* MERCHANTLIMIT 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.mission;
import javax.xml.stream.XMLStreamException;
import net.sf.freecol.common.io.FreeColXMLWriter;
import net.sf.freecol.common.model.Unit;
/**
* The Mission interface describes some kind of order that can be
* given to a {@link Unit}, such as the order to move to a certain
* Tile, attack a certain Unit, or build a TileImprovement, for
* example. Missions can be atomic, or combine a number of simpler
* Missions.
*/
public interface Mission {
enum MissionState {
/**
* Mission is in progress.
*/
OK,
/**
* Mission has been completed.
*/
COMPLETED,
/**
* Mission is temporarily blocked, e.g. by another Unit.
*/
BLOCKED,
/**
* Mission has been aborted, e.g. because a target or
* destination has been destroyed.
*/
ABORTED
};
/**
* Attempts to carry out the mission and returns an appropriate
* MissionState.
*
* @return a {@code MissionState} value
*/
MissionState doMission();
/**
* Returns true if the mission is still valid. This might not be
* the case if its target or destination have been destroyed, or
* if the Unit this mission was assigned to was destroyed or
* changed owner, for example.
*
* @return a {@code boolean} value
*/
boolean isValid();
/**
* Return the Unit this mission was assigned to.
*
* @return an {@code Unit} value
*/
Unit getUnit();
/**
* This method writes an XML-representation of this object to
* the given stream.
*
* @param xw The {@code FreeColXMLWriter} to write to.
* @throws XMLStreamException if there are any problems writing
* to the stream.
*/
void toXML(FreeColXMLWriter xw) throws XMLStreamException;
}