/** * Title:        AbstractSearchEngine<p> * Description:  Abstract search engine for searching paths in a maze<p> * Copyright:    Copyright (c) Mark Watson, Released under Open Source Artistic License<p> * Company:      Mark Watson Associates<p> * @author Mark Watson * @version 1.0 */import java.awt.Dimension;public class AbstractSearchEngine {    public AbstractSearchEngine(int width, int height) {        maze = new Maze(width, height);        initSearch();    }    public Maze getMaze() { return maze; }    protected Maze maze;    /**     * We will use the Java type Dimension (fields width and height will     * encode the coordinates in x and y directions) for the search path:     */    protected Dimension [] searchPath = null;    protected int pathCount;    protected int maxDepth;    protected Dimension startLoc, goalLoc, currentLoc;    protected boolean isSearching = true;    protected void initSearch() {        if (searchPath == null) {            searchPath = new Dimension[1000];            for (int i=0; i<1000; i++) {                searchPath[i] = new Dimension();            }        }        pathCount = 0;        startLoc = maze.startLoc;        currentLoc = startLoc;        goalLoc = maze.goalLoc;        searchPath[pathCount++] = currentLoc;    }    protected boolean equals(Dimension d1, Dimension d2) {        return d1.getWidth() == d2.getWidth() && d1.getHeight() == d2.getHeight();    }    public Dimension [] getPath() {      Dimension [] ret = new Dimension[maxDepth];      for (int i=0; i<maxDepth; i++) {        ret[i] = searchPath[i];      }      return ret;    }    protected Dimension [] getPossibleMoves(Dimension loc) {        Dimension tempMoves [] = new Dimension[4];        tempMoves[0] = tempMoves[1] = tempMoves[2] = tempMoves[3] = null;        int x = loc.width;        int y = loc.height;        int num = 0;        if (maze.getValue(x - 1, y) == 0 || maze.getValue(x - 1, y) == Maze.GOAL_LOC_VALUE) {            tempMoves[num++] = new Dimension(x - 1, y);        }        if (maze.getValue(x + 1, y) == 0 || maze.getValue(x + 1, y) == Maze.GOAL_LOC_VALUE) {            tempMoves[num++] = new Dimension(x + 1, y);        }        if (maze.getValue(x, y - 1) == 0 || maze.getValue(x, y - 1) == Maze.GOAL_LOC_VALUE) {            tempMoves[num++] = new Dimension(x, y - 1);        }        if (maze.getValue(x, y + 1) == 0 || maze.getValue(x, y + 1) == Maze.GOAL_LOC_VALUE) {            tempMoves[num++] = new Dimension(x, y + 1);        }        return tempMoves;    }}