coordinatecanvas.java

ErGo是一个很早的Java通用围棋服务器(IGS/NNGS)客户端程序。有全部源码和文档

package ergo.ui;

// $Id: CoordinateCanvas.java,v 1.2 1999/08/13 01:20:07 sigue Exp $

/*
 *  Copyright (C) 1999  Carl L. Gay and Antranig M. Basman.
 *  See the file copyright.txt, distributed with this software,
 *  for further information.
 */

import ergo.*;
import ergo.util.*;

import java.awt.*;

/**************************************************************
 * CoordinateCanvas                                           *
 *                                                            *
 * A canvas for displaying the coordinates along the          *
 * edge of the board.                                         *
 **************************************************************/

public class CoordinateCanvas extends ErgoCanvas implements Optionizable {
  private static final char[] temp = new char[2];
  private GameWindow gwin;
  private String position;
  private int gameSize;
  private int pad = 2;

  private String coordinateString = "Coordinate font";
  private Font coordinateFont = null;
  private Optionizer opser = Ergo.opser;

  CoordinateCanvas (String position, GameWindow win) {
    try {
      opser.expressOwnership(coordinateString, Optionizer.TYPE_FONT,
			     this, null);
      coordinateFont = Ergo.opser.getFontOption(coordinateString);
      opser.expressOwnership(GlobalOptions.gwinColorString, 
			     Optionizer.TYPE_COLOR, this,
			     new ColorSpec(win.gwinDefaultBackground));
      setBackground(opser.getColorOption(GlobalOptions.gwinColorString));
    }
    catch (Exception e) {
      Debug.backtrace(e);
    }
    this.position = position;
    gwin = win;
    gameSize = win.game.size();
    setFont(coordinateFont);
  }

  // support the Optionizable interface.

  public void optionEvent(String keyword, Object value) {
    if (opser.isSameKey(keyword, coordinateString)) {
      coordinateFont = (Font)value;
      setFont(coordinateFont);
      // +++ Is this correct, or is refresh() required also?
      // validate(); 
      // invalidate();
    }
    else if (opser.isSameKey(keyword, GlobalOptions.gwinColorString)) {
      setBackground(opser.getColorOption(GlobalOptions.gwinColorString));
      repaint();
    }
  }


  public void update (Graphics g) { redisplay(g, false); }

  public void paint (Graphics g) { redisplay(g, true); }

  private void redisplay (Graphics g, boolean forcep) {
    if (needsRedisplay
	|| forcep
	|| getSize().height != height
	|| getSize().width != width) {
      width = getSize().width;
      height = getSize().height;
      //g.setFont(gwin.SMALLFONT);
      FontMetrics metrics = g.getFontMetrics();
      g.setColor(getBackground());
      g.fillRect(0, 0, width, height);
      g.setColor(getForeground());

      int step = (((isVertical() ? height : width) - (2 * gwin.getBevelWidth()))
		  / gameSize);
      int start = (isVertical()
		   ? ((step - metrics.getHeight()) / 2 + metrics.getAscent())
		   : (step / 2)) + gwin.getBevelWidth();
      if (isHorizontal()) {
	int y = position.equalsIgnoreCase("south")
	  ? (metrics.getAscent() + pad)
	  : (height - metrics.getDescent() - pad);
	for (int i = 0; i < gameSize; i++) {
	  int index = (i < 25) ? i : i - 25;
	  int it = 'A' + ((index <= 7) ? index : index + 1);
	  temp[0] = (i < 25) ? (char)it : Character.toLowerCase((char)it);
	  g.drawChars(temp, 0, 1, start + i * step, y);
	}
      }
      else if (isVertical())
	for (int i = gameSize; i > 0; i--) {
	  temp[0] = (i < 10) ? ' ' : Util.DIGITS[i / 10];
	  temp[1] = Util.DIGITS[i % 10];
	  int y = start + (gameSize - i) * step;
	  if (position.equalsIgnoreCase("east")) {
	    if (i < 10)
	      g.drawChars(temp, 1, 1, pad, y);
	    else
	      g.drawChars(temp, 0, 2, pad, y);
	  } else
	    g.drawChars(temp, 0, 2,
			(width - metrics.charsWidth(temp, 0, 2) - pad), y);
	}
    }
  }

  private boolean isVertical () {
    return (position.equalsIgnoreCase("East")
	    || position.equalsIgnoreCase("West"));
  }

  private boolean isHorizontal () {
    return (position.equalsIgnoreCase("South")
	    || position.equalsIgnoreCase("North"));
  }

  private Dimension sizeForFont (Font f) {
    Dimension d = new Dimension();
    FontMetrics m = getFontMetrics(f);
    if (isVertical()) {
      d.width = m.stringWidth("19");
      d.height = m.getHeight() * gameSize; }
    else {
      d.width = m.stringWidth("A") * gameSize;
      d.height = m.getHeight(); }
    d.width += pad * 2;
    d.height += pad * 2;
    return d;
  }

  public Dimension getMinimumSize () {
    return getPreferredSize();
  }

  public Dimension getPreferredSize () {
    return sizeForFont(getFont());
  }

  /**
    * Shift clicking in a coord canvas hides it.
    */
/*
  public boolean mouseUp (Event e, int x, int y) {
    if (e.shiftDown()) {
      gwin.toggleCoordinates(this);
      return true; }
    else
      return false;
  }
  */

}  // end of class CoordinateCanvas