Java by API/javax.swing.tree/TreePath

new TreePath(Object singlePath)

 
import java.awt.BorderLayout;
import java.util.Vector;
import javax.swing.JFrame;
import javax.swing.JScrollPane;
import javax.swing.JTree;
import javax.swing.tree.DefaultTreeModel;
import javax.swing.tree.TreeModel;
import javax.swing.tree.TreePath;
public class MainClass {
  public static void main(String args[]) {
    JFrame frame = new JFrame("Swing Package Hierarchy");
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    Vector rootVector = new TreeVector("A", new String[] { "a" });
    JTree tree = new JTree(rootVector);
    tree.setRootVisible(true);
    TreeModel model = tree.getModel();
    model.valueForPathChanged(new TreePath(model.getRoot()), "javax.swing");
    ((DefaultTreeModel) model).reload();
    JScrollPane scrollPane = new JScrollPane(tree);
    frame.getContentPane().add(scrollPane, BorderLayout.CENTER);
    frame.setSize(300, 300);
    frame.setVisible(true);
  }
}
class TreeVector extends Vector {
  String name;
  TreeVector(String name) {
    this.name = name;
  }
  TreeVector(String name, Object elements[]) {
    this.name = name;
    for (int i = 0, n = elements.length; i < n; i++) {
      add(elements[i]);
    }
  }
  public String toString() {
    return name;
  }
}

TreeNode: children()

 
import java.awt.BorderLayout;
import java.util.Enumeration;
import javax.swing.JFrame;
import javax.swing.JScrollPane;
import javax.swing.JTree;
import javax.swing.event.TreeSelectionEvent;
import javax.swing.event.TreeSelectionListener;
import javax.swing.tree.DefaultMutableTreeNode;
import javax.swing.tree.TreeModel;
import javax.swing.tree.TreeNode;
import javax.swing.tree.TreePath;
public class MainClass {
  public static void main(String args[]) {
    JFrame frame = new JFrame("Traverse Tree");
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    JTree tree = new JTree();
    tree.setRootVisible(true);
    TreeModel model = tree.getModel();
    Object rootObject = model.getRoot();
    if ((rootObject != null) && (rootObject instanceof DefaultMutableTreeNode)) {
      DefaultMutableTreeNode r = (DefaultMutableTreeNode) rootObject;
      printDescendents(r);
      Enumeration breadth = r.breadthFirstEnumeration();
      Enumeration depth = r.depthFirstEnumeration();
      Enumeration preOrder = r.preorderEnumeration();
      printEnumeration(breadth, "Breadth");
      printEnumeration(depth, "Depth");
      printEnumeration(preOrder, "Pre");
    }
    TreeSelectionListener treeSelectionListener = new TreeSelectionListener() {
      public void valueChanged(TreeSelectionEvent treeSelectionEvent) {
        JTree treeSource = (JTree) treeSelectionEvent.getSource();
        TreePath path = treeSource.getSelectionPath();
        System.out.println(path);
        System.out.println(path.getPath());
        System.out.println(path.getParentPath());
        System.out.println(((DefaultMutableTreeNode) path.getLastPathComponent()).getUserObject());
        System.out.println(path.getPathCount());
      }
    };
    tree.addTreeSelectionListener(treeSelectionListener);
    JScrollPane scrollPane = new JScrollPane(tree);
    frame.add(scrollPane, BorderLayout.CENTER);
    frame.setSize(300, 400);
    frame.setVisible(true);
  }
  private static void printEnumeration(Enumeration e, String label) {
    System.out.println("-----" + label + "-----");
    while (e.hasMoreElements()) {
      System.out.println(e.nextElement());
    }
  }
  public static void printDescendents(TreeNode root) {
    System.out.println(root);
    Enumeration children = root.children();
    if (children != null) {
      while (children.hasMoreElements()) {
        printDescendents((TreeNode) children.nextElement());
      }
    }
  }
}

TreePath: getLastPathComponent()

 
import java.awt.BorderLayout;
import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTextField;
import javax.swing.JTree;
import javax.swing.event.TreeSelectionEvent;
import javax.swing.event.TreeSelectionListener;
import javax.swing.tree.DefaultMutableTreeNode;
import javax.swing.tree.DefaultTreeModel;
import javax.swing.tree.MutableTreeNode;
import javax.swing.tree.TreePath;
public class MainClass extends JPanel {
  public static void main(String[] args) {
    // create a hierarchy of nodes
    MutableTreeNode root = new DefaultMutableTreeNode("A");
    MutableTreeNode bNode = new DefaultMutableTreeNode("B");
    MutableTreeNode cNode = new DefaultMutableTreeNode("C");
    root.insert(bNode, 0);
    root.insert(cNode, 1);
    bNode.insert(new DefaultMutableTreeNode("1"), 0);
    bNode.insert(new DefaultMutableTreeNode("2"), 1);
    cNode.insert(new DefaultMutableTreeNode("1"), 0);
    cNode.insert(new DefaultMutableTreeNode("2"), 1);
    final DefaultTreeModel model = new DefaultTreeModel(root);
    final JTree tree = new JTree(model);
    final JTextField nameField = new JTextField("Z");
    final JButton button = new JButton("Add");
    button.setEnabled(false);
    button.addActionListener(new ActionListener() {
      public void actionPerformed(ActionEvent e) {
        TreePath tp = tree.getSelectionPath();
        MutableTreeNode insertNode = (MutableTreeNode) tp.getLastPathComponent();
        int insertIndex = 0;
        if (insertNode.getParent() != null) {
          MutableTreeNode parent = (MutableTreeNode) insertNode.getParent();
          insertIndex = parent.getIndex(insertNode) + 1;
          insertNode = parent;
        }
        MutableTreeNode node = new DefaultMutableTreeNode(nameField.getText());
        model.insertNodeInto(node, insertNode, insertIndex);
      }
    });
    JPanel addPanel = new JPanel(new GridLayout(2, 1));
    addPanel.add(nameField);
    addPanel.add(button);
    tree.addTreeSelectionListener(new TreeSelectionListener() {
      public void valueChanged(TreeSelectionEvent e) {
        TreePath tp = e.getNewLeadSelectionPath();
        button.setEnabled(tp != null);
      }
    });
    JFrame frame = new JFrame();
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    frame.setSize(200, 200);
    frame.getContentPane().add(new JScrollPane(tree));
    frame.getContentPane().add(addPanel, BorderLayout.SOUTH);
    frame.setVisible(true);
  }
}

TreePath: getPathCount()

 
import java.awt.BorderLayout;
import java.util.Enumeration;
import javax.swing.JFrame;
import javax.swing.JScrollPane;
import javax.swing.JTree;
import javax.swing.event.TreeSelectionEvent;
import javax.swing.event.TreeSelectionListener;
import javax.swing.tree.DefaultMutableTreeNode;
import javax.swing.tree.TreeModel;
import javax.swing.tree.TreeNode;
import javax.swing.tree.TreePath;
public class MainClass {
  public static void main(String args[]) {
    JFrame frame = new JFrame("Traverse Tree");
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    JTree tree = new JTree();
    tree.setRootVisible(true);
    TreeModel model = tree.getModel();
    Object rootObject = model.getRoot();
    if ((rootObject != null) && (rootObject instanceof DefaultMutableTreeNode)) {
      DefaultMutableTreeNode r = (DefaultMutableTreeNode) rootObject;
      printDescendents(r);
      Enumeration breadth = r.breadthFirstEnumeration();
      Enumeration depth = r.depthFirstEnumeration();
      Enumeration preOrder = r.preorderEnumeration();
      printEnumeration(breadth, "Breadth");
      printEnumeration(depth, "Depth");
      printEnumeration(preOrder, "Pre");
    }
    TreeSelectionListener treeSelectionListener = new TreeSelectionListener() {
      public void valueChanged(TreeSelectionEvent treeSelectionEvent) {
        JTree treeSource = (JTree) treeSelectionEvent.getSource();
        TreePath path = treeSource.getSelectionPath();
        System.out.println(path);
        System.out.println(path.getPath());
        System.out.println(path.getParentPath());
        System.out.println(((DefaultMutableTreeNode) path.getLastPathComponent()).getUserObject());
        System.out.println(path.getPathCount());
      }
    };
    tree.addTreeSelectionListener(treeSelectionListener);
    JScrollPane scrollPane = new JScrollPane(tree);
    frame.add(scrollPane, BorderLayout.CENTER);
    frame.setSize(300, 400);
    frame.setVisible(true);
  }
  private static void printEnumeration(Enumeration e, String label) {
    System.out.println("-----" + label + "-----");
    while (e.hasMoreElements()) {
      System.out.println(e.nextElement());
    }
  }
  public static void printDescendents(TreeNode root) {
    System.out.println(root);
    Enumeration children = root.children();
    if (children != null) {
      while (children.hasMoreElements()) {
        printDescendents((TreeNode) children.nextElement());
      }
    }
  }
}

TreePath: pathByAddingChild(Object child)

  
import java.util.Enumeration;
import javax.swing.JTree;
import javax.swing.tree.TreeNode;
import javax.swing.tree.TreePath;
public class Main {
  public static void main(String[] argv) throws Exception {
    JTree tree = new JTree();
    TreePath path = findByName(tree, new String[] { "JTree", "A", "a" });
  }
  public static TreePath findByName(JTree tree, String[] names) {
    TreeNode root = (TreeNode) tree.getModel().getRoot();
    return find(tree, new TreePath(root), names, 0);
  }
  private static TreePath find(JTree tree, TreePath parent, Object[] nodes, int depth) {
    TreeNode node = (TreeNode) parent.getLastPathComponent();
    Object o = node;
    if (o.equals(nodes[depth])) {
      if (depth == nodes.length - 1) {
        return parent;
      }
      if (node.getChildCount() >= 0) {
        for (Enumeration e = node.children(); e.hasMoreElements();) {
          TreeNode n = (TreeNode) e.nextElement();
          TreePath path = parent.pathByAddingChild(n);
          TreePath result = find(tree, path, nodes, depth + 1);
          if (result != null) {
            return result;
          }
        }
      }
    }
    return null;
  }
}

TreePath: toString()

 
import java.awt.BorderLayout;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTextField;
import javax.swing.JTree;
import javax.swing.ScrollPaneConstants;
import javax.swing.tree.DefaultMutableTreeNode;
import javax.swing.tree.TreePath;
public class MainClass extends JPanel {
  public MainClass() {
    final JTree tree;
    final JTextField jtf;
    DefaultMutableTreeNode top = new DefaultMutableTreeNode("Options");
    DefaultMutableTreeNode a = new DefaultMutableTreeNode("A");
    top.add(a);
    DefaultMutableTreeNode a1 = new DefaultMutableTreeNode("A1");
    a.add(a1);
    DefaultMutableTreeNode a2 = new DefaultMutableTreeNode("A2");
    a.add(a2);
    DefaultMutableTreeNode b = new DefaultMutableTreeNode("B");
    top.add(b);
    DefaultMutableTreeNode b1 = new DefaultMutableTreeNode("B1");
    b.add(b1);
    DefaultMutableTreeNode b2 = new DefaultMutableTreeNode("B2");
    b.add(b2);
    DefaultMutableTreeNode b3 = new DefaultMutableTreeNode("B3");
    b.add(b3);
    tree = new JTree(top);
    JScrollPane jsp = new JScrollPane(tree);
    add(jsp, BorderLayout.CENTER);
    jtf = new JTextField("", 20);
    add(jtf, BorderLayout.SOUTH);
    tree.addMouseListener(new MouseAdapter() {
      public void mouseClicked(MouseEvent me) {
        TreePath tp = tree.getPathForLocation(me.getX(), me.getY());
        if (tp != null)
          jtf.setText(tp.toString());
        else
          jtf.setText("");
      }
    });
  }
  public static void main(String[] args) {
    JFrame frame = new JFrame();
    frame.getContentPane().add(new MainClass());
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    frame.setSize(200, 200);
    frame.setVisible(true);
  }
}