日期:2014-05-20 浏览次数:20941 次
/** @version 1.02 2004-08-21 @author Cay Horstmann */ package ultrapower; import java.awt.*; import java.awt.event.*; import javax.swing.*; import javax.swing.tree.*; /** This program demonstrates tree editing. */ public class TreeEditTest { public static void main(String[] args) { JFrame frame = new TreeEditFrame(); frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); frame.setVisible(true); } } /** A frame with a tree and buttons to edit the tree. */ class TreeEditFrame extends JFrame { Container c=this.getContentPane(); public TreeEditFrame() { setTitle("TreeEditTest"); setSize(DEFAULT_WIDTH, DEFAULT_HEIGHT); // construct tree TreeNode root = makeSampleTree(); model = new DefaultTreeModel(root); tree = new JTree(model); tree.setEditable(true); // add scroll pane with tree JScrollPane scrollPane = new JScrollPane(tree); c.add(scrollPane, BorderLayout.CENTER); makeButtons(); } public TreeNode makeSampleTree() { DefaultMutableTreeNode root = new DefaultMutableTreeNode("World"); DefaultMutableTreeNode country = new DefaultMutableTreeNode("USA"); root.add(country); DefaultMutableTreeNode state = new DefaultMutableTreeNode("California"); country.add(state); DefaultMutableTreeNode city = new DefaultMutableTreeNode("San Jose"); state.add(city); city = new DefaultMutableTreeNode("San Diego"); state.add(city); state = new DefaultMutableTreeNode("Michigan"); country.add(state); city = new DefaultMutableTreeNode("Ann Arbor"); state.add(city); country = new DefaultMutableTreeNode("Germany"); root.add(country); state = new DefaultMutableTreeNode("Schleswig-Holstein"); country.add(state); city = new DefaultMutableTreeNode("Kiel"); state.add(city); return root; } /** Makes the buttons to add a sibling, add a child, and delete a node. */ public void makeButtons() { JPanel panel = new JPanel(); JButton addSiblingButton = new JButton("Add Sibling"); addSiblingButton.addActionListener(new ActionListener() { public void actionPerformed(ActionEvent event) { DefaultMutableTreeNode selectedNode = (DefaultMutableTreeNode) tree.getLastSelectedPathComponent(); if (selectedNode == null) return; DefaultMutableTreeNode parent = (DefaultMutableTreeNode) selectedNode.getParent(); if (parent == null) return; DefaultMutableTreeNode newNode = new DefaultMutableTreeNode("New"); int selectedIndex = parent.getIndex(selectedNode); model.insertNodeInto(newNode, parent, selectedIndex + 1); // now display new node TreeNode[] nodes = model.getPathToRoot(newNode); TreePath path = new TreePath(nodes); tree.scrollPathToVisible(path); } }); panel.add(addSiblingButton); JButton addChildButton = new JButton("Add Child"); addChildButton.addActionListener(new ActionListener() { public void actionPerformed(ActionEvent event) { DefaultMutableTreeNode selectedNode = (DefaultMutableTreeNode) tree.getLastSelectedPathComponent(); if (selectedNode == null) return; DefaultMutableTreeNode newNode = new DefaultMutableTreeNode("New"); model.insertNodeInto(newNode, selectedNode, selectedNode.getChildCount()); // now display new node TreeNode[] nodes = model.getPathToRoot(newNode); TreePath path = new TreePath(nodes); tree.scrollPathToVisible(path); } }); panel.add(addChildButton); JButton deleteButton = new JButton("Delete"); deleteButton.addActionListener(new ActionListener() { public void actionPerformed(ActionEvent event) { DefaultMutableTreeNode selectedNode = (DefaultMutableTreeNode) tree.getLastSelectedPathComponent(); if (selectedNode != null && selectedNode.getParent() != null) model.removeNodeFromParent(selectedNode); } }); panel.add(deleteButton); c.add(panel, BorderLayout.SOUTH); } private DefaultTreeModel model; private JTree tree; private static final int DEFAULT_WIDTH = 400; private static final int DEFAULT_HEIGHT = 200; }