MapXMLLoader.java

package vooga.towerdefense.gameeditor.gameloader.xmlloaders;

import java.awt.Dimension;
import java.lang.reflect.Field;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.Scanner;
import org.w3c.dom.Element;
import util.Location;
import vooga.towerdefense.util.Pixmap;
import util.XMLTool;
import vooga.towerdefense.gameeditor.controller.GameEditorController;
import vooga.towerdefense.model.GameMap;
import vooga.towerdefense.model.Tile;
import vooga.towerdefense.model.tiles.factories.TileFactory;
import vooga.towerdefense.model.tiles.factories.XMLTileFactory;


/**
 * This class is responsible for constructing GameMap objects
 * from an xml file describing different game maps.
 * 
 * An example of this xml file is shown below:
 * 
 * <map>
 * <map1>
 * <image></image>
 * <dimension>
 * <width>800</width>
 * <height>600</height>
 * </dimension>
 * <tile_size>50</tile_size>
 * <grid>
 * 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
 * 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
 * 0 0 0 1 1 1 1 1 0 0 0 0 0 0 0 0
 * 0 0 0 1 0 0 0 1 0 0 0 1 1 1 0 0
 * 0 0 0 1 0 0 0 1 0 0 0 1 0 1 0 0
 * 1 1 1 1 0 0 0 1 1 1 1 1 0 1 1 1
 * 0 0 0 1 0 0 0 1 0 0 0 1 0 1 0 0
 * 0 0 0 1 0 0 0 1 0 0 0 1 1 1 0 0
 * 0 0 0 1 1 1 1 1 0 0 0 0 0 0 0 0
 * 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
 * 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
 * 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
 * </grid>
 * </map1>
 * <map2>
 * <image></image>
 * <dimension>
 * <width>800</width>
 * <height>600</height>
 * </dimension>
 * <tile_size>50</tile_size>
 * <grid>
 * 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
 * 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
 * 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
 * 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
 * 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
 * 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1
 * 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
 * 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
 * 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
 * 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
 * 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
 * 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
 * </grid>
 * </map2>
 * </map>
 * 
 * This file is read, and a List of GameMap objects can be returned.
 * 
 * @author Erick Gonzalez
 */
public class MapXMLLoader {
    private static final String IMAGE_PATH = "/vooga/towerdefense/images/";
    private static final String TILE_FACTORIES_CLASSPATH =
            "vooga.towerdefense.model.tiles.factories";
    
    // map_loadfile.xml tags
    private static final String MAP_TAG = "map";
    private static final String IMAGE_TAG = "image";
    private static final String DIMENSION_TAG = "dimension";
    private static final String WIDTH_TAG = "width";
    private static final String HEIGHT_TAG = "height";
    private static final String TILE_SIZE_TAG = "tile_size";
    private static final String GRID_TAG = "grid";
    private static final String TILE_TAG = "tileType";
    private static final String TILE_ID_TAG = "ID";
    
    private XMLTool myXMLTool;
    private Map<String, TileFactory> myTileIdMap;
    
    /**
     * 
     * @param xmlTool an XMLTool with an xml file
     */
    public MapXMLLoader(XMLTool xmlTool) {
        myXMLTool = xmlTool;
        myTileIdMap = getTileIdMap();
    }
    
    /**
     * Loads all the maps described in the xml file.
     * 
     * @return a list of GameMap objects
     */
    public List<GameMap> loadMaps () {
        List<GameMap> gameMaps = new ArrayList<GameMap>();
        // TODO: mapElement needs to be passed in as a parameter
        Element mapElement = myXMLTool.getElement(MAP_TAG);
        
        List<Element> subElements = myXMLTool.getChildrenList(mapElement);
        for (Element subElement : subElements) {
            GameMap map = loadMap(subElement);
            gameMaps.add(map);
        }
        return gameMaps;
    }
    
    private GameMap loadMap (Element mapNameElement) {
        Map<String, Element> subElements = myXMLTool.getChildrenElementMap(mapNameElement);
        Pixmap mapImage = loadMapImage(subElements.get(IMAGE_TAG));
        Dimension mapDimensions = loadMapDimensions(subElements.get(DIMENSION_TAG));
        Dimension tileSize = loadMapTileSize(subElements.get(TILE_SIZE_TAG));
        
        GameMap map = new GameMap(mapImage, mapDimensions, tileSize);
        createAndSetGrid(subElements.get(GRID_TAG), map);
        return map;
    }
    
    private Pixmap loadMapImage (Element imageElement) {
        String imagePath = myXMLTool.getContent(imageElement);
        return new Pixmap(IMAGE_PATH + imagePath);
    }
    
    private Dimension loadMapDimensions (Element dimensionElement) {
        Map<String, Element> subElementMap = myXMLTool.getChildrenElementMap(dimensionElement);
        
        int width = getMapWidth(subElementMap.get(WIDTH_TAG));
        int height = getMapHeight(subElementMap.get(HEIGHT_TAG));
        return new Dimension(width, height);
    }
    
    private int getMapWidth (Element widthElement) {
        return Integer.parseInt(myXMLTool.getContent(widthElement));
    }
    
    private int getMapHeight (Element heightElement) {
        return Integer.parseInt(myXMLTool.getContent(heightElement));
    }
    
    private Dimension loadMapTileSize (Element tileSizeElement) {
        int tileSize = Integer.parseInt(myXMLTool.getContent(tileSizeElement));
        return new Dimension(tileSize, tileSize);
    }
    
    private void createAndSetGrid (Element tilesElement, GameMap map) {
        Dimension mapDimensions = map.getSize();
        Dimension tileDimensions = map.getTileSize();
        
        String gridString = myXMLTool.getContent(tilesElement);
        Scanner reader = new Scanner(gridString);
        
        int horizontalTileCount = (int) (mapDimensions.getWidth() / tileDimensions.getWidth());
        int verticalTileCount = (int) (mapDimensions.getHeight() / tileDimensions.getHeight());
        
        Tile[][] grid = new Tile[horizontalTileCount][verticalTileCount];
        
        for (int i = 0; i < grid[0].length; i++) {
            for (int j = 0; j < grid.length; j++) {
                int xCenter = (int) (j * tileDimensions.getWidth() +
                        tileDimensions.getWidth() / 2);
                int yCenter = (int) (i * tileDimensions.getHeight() +
                        tileDimensions.getHeight() / 2);
                String tileId = reader.next();
                Location location = new Location(xCenter, yCenter);
                grid[j][i] = getTileFactory(tileId).createTile(location, map);
            }
        }
        map.setGrid(grid);
    }
    
    private TileFactory getTileFactory (String tileId) {
        return myTileIdMap.get(tileId);
    }
    
    @SuppressWarnings("rawtypes")
    private Map<String, TileFactory> getTileIdMap () {
        Map<String, TileFactory> tileIdMap = new HashMap<String, TileFactory>();
        List<Class> tileFactoryClasses = GameEditorController.
                getClassesInPackage(TILE_FACTORIES_CLASSPATH);
        for (Class c : tileFactoryClasses) {
            Object tileFactory;
            try {
                tileFactory = c.newInstance();
                Field f = c.getField("ID");
                Object id = f.get(tileFactory);
                tileIdMap.put((String) id, (TileFactory) tileFactory);
            }
            catch (InstantiationException e) {
                // null behavior on purpose, don't initialize tile factory
            }
            catch (IllegalAccessException e) {
                // null behavior on purpose, don't initialize tile factory
            }
            catch (NoSuchFieldException e) {
                // null behavior on purpose, don't initialize tile factory
            }
            catch (SecurityException e) {
                // null behavior on purpose, don't initialize tile factory
            }
        }
        Element parentElement = myXMLTool.getElement(TILE_TAG);
        if (parentElement != null) {
            List<Element> tileElements = myXMLTool.getChildrenList(parentElement);
            for (Element e : tileElements) {
                String tag = myXMLTool.getTagName(e);
                tileIdMap
                        .put(tag.substring(2), (TileFactory) new XMLTileFactory(myXMLTool, e, tag));
            }
        }
        return tileIdMap;
    }
}