SWT GC 五子棋

public class FiveChess extends BaseWindow{ private Listener listener; private Canvas canvas; private Rectangle clickArea; private static int N=20; private static int DIV=15; private Rectangle[][] rect=new Rectangle[N][N]; private String[][] flags=new String[N][N]; private boolean[][] dirty=new boolean[N][N]; private GC gc; private int hot_i,hot_j; private boolean flag=true; /** * listener is use to action in draw