Java by API/javax.swing.event/TreeSelectionEvent

TreeSelectionEvent: getNewLeadSelectionPath()

   <source lang="java">

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);
 }

}

 </source>
   
  
 
  

TreeSelectionEvent: isAddedPath(int index)

   <source lang="java">
 

import javax.swing.JTree; import javax.swing.event.TreeSelectionEvent; import javax.swing.event.TreeSelectionListener; import javax.swing.tree.TreePath; public class Main {

 public static void main(String[] argv) throws Exception {
   JTree tree = new JTree();
   tree.addTreeSelectionListener(new TreeSelectionListener() {
     public void valueChanged(TreeSelectionEvent evt) {
       TreePath[] paths = evt.getPaths();
       for (int i = 0; i < paths.length; i++) {
         if (evt.isAddedPath(i)) {
           System.out.println("This node has been selected");
         } else {
           System.out.println("This node has been deselected"); 
         }
       }
     }
   });
 }

}

 </source>