import java.awt.BorderLayout;
import java.awt.Dimension;
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.JTree;
import javax.swing.event.TreeModelEvent;
import javax.swing.event.TreeModelListener;
import javax.swing.tree.DefaultMutableTreeNode;
import javax.swing.tree.DefaultTreeModel;
import javax.swing.tree.MutableTreeNode;
import javax.swing.tree.TreePath;
import javax.swing.tree.TreeSelectionModel;
public class Main extends JPanel implements ActionListener {
int newNodeSuffix = 1;
static String ADD_COMMAND = "add";
static String REMOVE_COMMAND = "remove";
static String CLEAR_COMMAND = "clear";
DynamicTree treePanel = new DynamicTree();
public Main() {
super(new BorderLayout());
populateTree(treePanel);
JButton addButton = new JButton("Add");
addButton.setActionCommand(ADD_COMMAND);
addButton.addActionListener(this);
JButton removeButton = new JButton("Remove");
removeButton.setActionCommand(REMOVE_COMMAND);
removeButton.addActionListener(this);
JButton clearButton = new JButton("Clear");
clearButton.setActionCommand(CLEAR_COMMAND);
clearButton.addActionListener(this);
treePanel.setPreferredSize(new Dimension(300, 150));
add(treePanel, BorderLayout.CENTER);
JPanel panel = new JPanel(new GridLayout(0, 3));
panel.add(addButton);
panel.add(removeButton);
panel.add(clearButton);
add(panel, BorderLayout.SOUTH);
}
public void populateTree(DynamicTree treePanel) {
String p1Name = "Parent 1";
String p2Name = "Parent 2";
String c1Name = "Child 1";
String c2Name = "Child 2";
DefaultMutableTreeNode p1, p2;
p1 = treePanel.addObject(null, p1Name);
p2 = treePanel.addObject(null, p2Name);
treePanel.addObject(p1, c1Name);
treePanel.addObject(p1, c2Name);
treePanel.addObject(p2, c1Name);
treePanel.addObject(p2, c2Name);
}
@Override
public void actionPerformed(ActionEvent e) {
String command = e.getActionCommand();
if (ADD_COMMAND.equals(command)) {
treePanel.addObject("New Node " + newNodeSuffix++);
} else if (REMOVE_COMMAND.equals(command)) {
treePanel.removeCurrentNode();
} else if (CLEAR_COMMAND.equals(command)) {
treePanel.clear();
}
}
public static void main(String[] args) {
JFrame frame = new JFrame();
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
Main newContentPane = new Main();
frame.setContentPane(newContentPane);
frame.pack();
frame.setVisible(true);
}
}
class DynamicTree extends JPanel {
DefaultMutableTreeNode rootNode = new DefaultMutableTreeNode("Root Node");
DefaultTreeModel treeModel = new DefaultTreeModel(rootNode);
JTree tree;
public DynamicTree() {
super(new GridLayout(1, 0));
treeModel.addTreeModelListener(new MyTreeModelListener());
tree = new JTree(treeModel);
tree.setEditable(true);
tree.getSelectionModel().setSelectionMode(
TreeSelectionModel.SINGLE_TREE_SELECTION);
tree.setShowsRootHandles(true);
JScrollPane scrollPane = new JScrollPane(tree);
add(scrollPane);
}
public void clear() {
rootNode.removeAllChildren();
treeModel.reload();
}
public void removeCurrentNode() {
TreePath currentSelection = tree.getSelectionPath();
if (currentSelection != null) {
DefaultMutableTreeNode currentNode = (DefaultMutableTreeNode) (currentSelection
.getLastPathComponent());
MutableTreeNode parent = (MutableTreeNode) (currentNode.getParent());
if (parent != null) {
treeModel.removeNodeFromParent(currentNode);
return;
}
}
}
public DefaultMutableTreeNode addObject(Object child) {
DefaultMutableTreeNode parentNode = null;
TreePath parentPath = tree.getSelectionPath();
if (parentPath == null) {
parentNode = rootNode;
} else {
parentNode = (DefaultMutableTreeNode) (parentPath.getLastPathComponent());
}
return addObject(parentNode, child, true);
}
public DefaultMutableTreeNode addObject(DefaultMutableTreeNode parent,
Object child) {
return addObject(parent, child, false);
}
public DefaultMutableTreeNode addObject(DefaultMutableTreeNode parent,
Object child, boolean shouldBeVisible) {
DefaultMutableTreeNode childNode = new DefaultMutableTreeNode(child);
if (parent == null) {
parent = rootNode;
}
treeModel.insertNodeInto(childNode, parent, parent.getChildCount());
if (shouldBeVisible) {
tree.scrollPathToVisible(new TreePath(childNode.getPath()));
}
return childNode;
}
class MyTreeModelListener implements TreeModelListener {
@Override
public void treeNodesChanged(TreeModelEvent e) {
DefaultMutableTreeNode node = (DefaultMutableTreeNode) (e.getTreePath()
.getLastPathComponent());
int index = e.getChildIndices()[0];
node = (DefaultMutableTreeNode) (node.getChildAt(index));
System.out.println("New value NodesChanged: " + node.getUserObject());
}
@Override
public void treeNodesInserted(TreeModelEvent e) {
DefaultMutableTreeNode node = (DefaultMutableTreeNode) (e.getTreePath()
.getLastPathComponent());
int index = e.getChildIndices()[0];
node = (DefaultMutableTreeNode) (node.getChildAt(index));
System.out.println("New value NodesInserted : " + node.getUserObject());
}
@Override
public void treeNodesRemoved(TreeModelEvent e) {
DefaultMutableTreeNode node = (DefaultMutableTreeNode) (e.getTreePath()
.getLastPathComponent());
int index = e.getChildIndices()[0];
node = (DefaultMutableTreeNode) (node.getChildAt(index));
System.out.println("New value NodesRemoved : " + node.getUserObject());
}
@Override
public void treeStructureChanged(TreeModelEvent e) {
DefaultMutableTreeNode node = (DefaultMutableTreeNode) (e.getTreePath()
.getLastPathComponent());
int index = e.getChildIndices()[0];
node = (DefaultMutableTreeNode) (node.getChildAt(index));
System.out.println("New value StructureChanged : " + node.getUserObject());
}
}
}