drawpanel.java

源程序（包括最初的版本

package treeandbtreedemo;

/**
 * <p>Title: 画板，节点不可移动</p>
 * <p>Description: 节点不可移动的画板。即直接在画板上画图</p>
 * <p>Copyright: Copyright (c) 2005</p>
 * <p>Company: </p>
 * @author not attributable
 * @version 2.0(2005.7.5)加入图形界面
 * @version 2.1(2005.7.5)初步加入动画和线程,产生节点的遍历动画效果
 * @version 2.2(2005.7.6)在基础架构中添加了二叉树类，把树和二叉树两种结构分开来做了
 *
 */
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
import javax.swing.event.*;
import javax.swing.border.*;

public class DrawPanel
    extends JPanel {
  Table t; //表格数据
  int current = -1; //控制遍历时所要画的节点
  //int r; //圆圈半径为10
  int index = -1;

  public DrawPanel() {
    t = new Table();
    current = -1;
    index = -1;
    //t.radius= 10;
  }

  public DrawPanel(Table t) {
    this.t = t;
    current = -1;
    index = -1;
    //r = 10;
  }

  /**重载paintComponent(Graphics g)方法画图*/
  public void paintComponent(Graphics g) {
    super.paintComponent(g);
    if (t.isEmpty() == true) {
      g.setColor(Color.white);
      g.fillRect(0, 0, this.getWidth(), this.getHeight());
    }
    else {
      paintTree(g); //画树

      if (index != -1 && index < t.number) { //当遍历时画点
        paintTree(g);
        paintNode(g, t.tables[current], Color.yellow);
        paintBottomNode(g, index, Color.yellow);
      }
    }
    // g.dispose();
  }

  public void paintTree(Graphics g) {
    //画线
    for (int i = 1; t.tables[i] != null; i++) {
      if (i > 0) {
        paintLine(g, t.tables[t.tables[i].parents], t.tables[i]);
      }
    }
    //画点
    for (int i = 0; t.tables[i] != null; i++) {
      paintNode(g, t.tables[i], Color.white);
    }

    //repaint();
  }

  /**画点*/
  public void paintNode(Graphics g, TableNode nodes, Color color) {
    //locateName(name)

    g.setColor(Color.RED);
    g.drawOval(nodes.getX() + this.getWidth() / 2 - t.r,
               nodes.getY() + this.getHeight() / 8 - t.r,
               t.r * 2, t.r * 2); //圆圈直径为20
    g.setColor(color);
    g.fillOval(nodes.getX() + this.getWidth() / 2 - t.r + 1,
               nodes.getY() + this.getHeight() / 8 - t.r + 1,
               t.r * 2 - 1, t.r * 2 - 1);
    g.setColor(Color.BLACK);
    g.drawString(nodes.name.toString(),
                 nodes.getX() + this.getWidth() / 2 - t.r + 7,
                 nodes.getY() + this.getHeight() / 8 - t.r + 14);
  }

  /**画线*/
  public void paintLine(Graphics g, TableNode nodes1, TableNode nodes2) {
    g.setColor(Color.BLACK);
    g.drawLine(nodes1.getX() + this.getWidth() / 2,
               nodes1.getY() + this.getHeight() / 8,
               nodes2.getX() + this.getWidth() / 2,
               nodes2.getY() + this.getHeight() / 8);
  }

  /**绘制画板底部的所遍历过的节点*/
  public void paintBottomNode(Graphics g, int index, Color color) {
    int w = 40;
    for (int i = 0; i <= index; i++, w += 40) {
      g.setColor(Color.RED);
      g.drawOval(w - t.r,
                 this.getHeight() - 20 - t.r,
                 t.r * 2, t.r * 2); //圆圈直径为20
      g.setColor(color);
      g.fillOval(w - t.r + 1,
                 this.getHeight() - 20 - t.r + 1,
                 t.r * 2 - 1, t.r * 2 - 1);
      g.setColor(Color.BLACK);
      g.drawString(t.tables[t.path[i]].name.toString(),
                   w - t.r + 7,
                   this.getHeight() - 20 - t.r + 14);

    }
  }

  /**设置表格*/
  public void setTable(Table ta) {
    t = ta;
  }

  /**设置当前节点*/
  public void setCurrent(int c) {
    current = t.path[c];
    index = c;
  }

  /**初始化画板*/
  public void InitDrawPanel() {
    t = new Table();
    current = -1;
    index = -1;
    t.r = 10;
    //this.repaint();

  }

}