treetest.java

< ProJavaProgrammingSecondEdition> 书中例程源码

import javax.swing.*;
import javax.swing.tree.*;

public class TreeTest extends JFrame {

  protected final static String[] questions = {
      "Green Kryptonite is only deadly " +
      "to beings from Krypton with superpowers",
      "Red Kryptonite's effects are permanent",
      "Gold Kryptonite permanently enhances superpowers",
      "Blue Kryptonite affects only Bizarros",
      "White Kryptonite affects only marine life",
      "Jewel Kryptonite was formed from Krypton's " +
      "Jewel Mountains"};

  public static void main(String[] args) {
    TreeTest tt = new TreeTest();
    tt.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    tt.setSize(500, 200);
    tt.setVisible(true);
  }

  public TreeTest() {
    super("Smallville University Final Exam");
    JTree tree = new JTree(getRootNode()) {
      public boolean isPathEditable(TreePath path) {
        Object comp = path.getLastPathComponent();
        if (comp instanceof DefaultMutableTreeNode) {
          DefaultMutableTreeNode node =
              (DefaultMutableTreeNode)comp;
          Object userObject = node.getUserObject();
          if (userObject instanceof TrueFalseQuestion) {
            return true;
          }
        }
        return false;
      }
    };
    QuestionCellRenderer renderer = new QuestionCellRenderer();
    tree.setCellRenderer(renderer);
    QuestionCellEditor editor = new QuestionCellEditor();
    tree.setCellEditor(editor);
    tree.setEditable(true);
    JScrollPane jsp = new JScrollPane(tree);
    getContentPane().add(jsp);
  }

  protected MutableTreeNode getRootNode() {
    DefaultMutableTreeNode root, child;
    TrueFalseQuestion question;
    root = new DefaultMutableTreeNode(
        "Kryptonite Questions -- Check all " +
        "of the following that are true " +
        "statements");
    for (int i = 0; i < questions.length; i++) {
      question = new TrueFalseQuestion(questions[i]);
      child = new DefaultMutableTreeNode(question);
      root.add(child);
    }
    return root;
  }

}