circlenode.java

源程序（包括最初的版本

package treeandbtreedemo;

/**
 * <p>Title:节点的图像，用了一个JLable的表示 </p>
 * <p>Description:节点的图形化显示 ，用了一个JLable的表示，有事件的监听。可拖动。</p>
 * <p>Copyright: Copyright (c) 2005</p>
 * <p>Company: </p>
 * @author not attributable
 * @version 3.0(2005.7.8)
 */
/**
 * <p>Title:节点的图像，用了一个JLable的表示 </p>
 * <p>Description:节点的图行显示 ，用了一个JLable的表示</p>
 * <p>Copyright: Copyright (c) 2005</p>
 * <p>Company: </p>
 * @author not attributable
 * @version 3.0(2005.7.8)
 */
import java.awt.*;
import java.awt.Dimension;
import javax.swing.*;
import java.awt.event.*;

public class CircleNode
    extends JLabel {
  String name; //节点名字
  //int color;//颜色
  int radius; //半径
  boolean fill; //填充
  //JLabel j=new JLabel();

  public CircleNode() {}

  public CircleNode(String name, int r, boolean fill) {
    this.name = name;
    radius = r;
    this.fill = fill;
    //paintComponent(this.getGraphics());
    this.setPreferredSize(new Dimension(radius * 2 + 2, radius * 2 + 2));
    this.setBackground(Color.white); //背景色
    this.setOpaque(false); //可见
    this.addMouseMotionListener(new MyLabel_mouseMotionAdapter(this));
    this.addMouseListener(new MyLabel_mouseAdapter(this));
  }

  public void paintComponent(Graphics g) {
    super.paintComponent(g);

    //外框
    g.setColor(Color.RED);
    g.drawOval(0, 0, radius * 2, radius * 2);

    //填充色
    if (fill == false) { //如果不需要填充颜色
      g.setColor(Color.WHITE);
      g.fillOval(1, 1, radius * 2 - 1, radius * 2 - 1); //填白色
    }
    else { //需要填充颜色
      g.setColor(Color.yellow);
      g.fillOval(1, 1, radius * 2 - 1, radius * 2 - 1); //填yellow色
    }

    //文字
    g.setColor(Color.BLACK);
    g.setFont(new Font("dialog", 0, 13));
    g.drawString(name, 7, 14);

  }

  public void setfill(boolean f) {
    fill = f;
    repaint();
  }

  /**鼠标移动事件*/
  class MyLabel_mouseMotionAdapter
      extends java.awt.event.MouseMotionAdapter {
    JLabel adaptee;

    MyLabel_mouseMotionAdapter(JLabel adaptee) {
      this.adaptee = adaptee;
    }

    public void mouseDragged(MouseEvent e) {
      adaptee.setLocation(adaptee.getX() + e.getX() - adaptee.getWidth() / 2,
                          adaptee.getY() + e.getY() - adaptee.getHeight() / 2);
      adaptee.getParent().repaint();
    }
  }

  /**鼠标点击事件*/
  class MyLabel_mouseAdapter
      extends java.awt.event.MouseAdapter {
    JLabel adaptee;

    MyLabel_mouseAdapter(JLabel adaptee) {
      this.adaptee = adaptee;
    }

    public void mousePressed(MouseEvent e) {
      adaptee.setCursor(Cursor.getPredefinedCursor(Cursor.HAND_CURSOR));
    }

    public void mouseReleased(MouseEvent e) {
      adaptee.setCursor(Cursor.getPredefinedCursor(Cursor.DEFAULT_CURSOR));
    }
  }

}