How to add buttons/text to right pane when selection is made from left pane

Question

Hi,
I am new to JAVA development with SWING.
I am trying to create an application where in the left pane there is a Tree Menu and in the right pane I have some buttons. Based on the selections in the left Pane, I should be able to add more buttons and or text to the right pane.
How do I accomplish this? If you guys have any sample code, Please post it or suggest different ways of accomplishing.
Thanks in advance.
user2325986

Answer 1

It looks like you are declaring different main_Frame, rightPane and leftPane and have too many items static and final. Take a look at the code below. I have set GridBagLayout for the frame for a better look.
I am not sure what you mean when you say that you want right panel only and want to add to it. Also, I think you would be better off using CardLayout for rightPanel as stated by jduprez
When you want to show code use {_code_} code here {_code_} tags (code in brackets without underscores)
Here is a working sample of what you had:
import javax.swing.*;
import javax.swing.event.*;
import java.awt.*;
import javax.swing.tree.*;
public class Main
    public static void main(String[] args)
        main_Frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        main_Frame.setVisible(true);
    public static TestFrame main_Frame = new TestFrame();
class TestFrame extends JFrame
    public TestFrame()
        setTitle("Test Frame");
        setSize(500, 500);
        setLayout(new GridBagLayout());
        leftGBC = new GridBagConstraints();
        leftGBC.gridx = 0;
        leftGBC.gridy = 0;
        leftGBC.fill = leftGBC.BOTH;
        leftGBC.weightx = 10;
        leftGBC.weighty = 100;
        rightGBC = new GridBagConstraints();
        rightGBC.gridx = 1;
        rightGBC.gridy = 0;
        rightGBC.fill = rightGBC.BOTH;
        rightGBC.weightx = 100;
        rightGBC.weighty = 100;
        leftPanel = new JPanel();
        leftPane = new JScrollPane(leftPanel);
        leftPane.setHorizontalScrollBarPolicy(JScrollPane.HORIZONTAL_SCROLLBAR_ALWAYS);
        leftPane.setVerticalScrollBarPolicy(JScrollPane.VERTICAL_SCROLLBAR_ALWAYS);
        rightPanel = new JPanel();
        rightPane = new JScrollPane(rightPanel);
        rightPane.setHorizontalScrollBarPolicy(JScrollPane.HORIZONTAL_SCROLLBAR_ALWAYS);
        rightPane.setVerticalScrollBarPolicy(JScrollPane.VERTICAL_SCROLLBAR_ALWAYS);
        DefaultMutableTreeNode root = new DefaultMutableTreeNode("main_Tree");
        DefaultMutableTreeNode Branch1 = new DefaultMutableTreeNode("Branch1");
        DefaultMutableTreeNode Leaf1 = new DefaultMutableTreeNode("Leaf1");
        root.add(Branch1);
        Branch1.add(Leaf1);
        DefaultMutableTreeNode Branch2 = new DefaultMutableTreeNode("Branch2");
        DefaultMutableTreeNode Leaf2 = new DefaultMutableTreeNode("Leaf2");
        root.add(Branch2);
        Branch2.add(Leaf2);
        JTree tree = new JTree(root);
        tree.setRootVisible(true);
        tree.setShowsRootHandles(true);
        tree.getSelectionModel().setSelectionMode(TreeSelectionModel.SINGLE_TREE_SELECTION);
        tree.addTreeSelectionListener(new TreeSelectionListener()
            public void valueChanged(TreeSelectionEvent se)
                JTree tree = (JTree) se.getSource();
                DefaultMutableTreeNode node = (DefaultMutableTreeNode)tree.getLastSelectedPathComponent();
                if (node == null) return;
                String nodeInfo = node.toString();
                if (nodeInfo.equals("Leaf1"))
                    rightPanel = new JPanel();
                    rightPanel.add(label);
                    Main.main_Frame.remove(rightPane);
                    rightPane = new JScrollPane(rightPanel);
                    rightPane.setHorizontalScrollBarPolicy(JScrollPane.HORIZONTAL_SCROLLBAR_ALWAYS);
                    rightPane.setVerticalScrollBarPolicy(JScrollPane.VERTICAL_SCROLLBAR_ALWAYS);
                    Main.main_Frame.add(rightPane, rightGBC);
                    Main.main_Frame.validate();
                    Main.main_Frame.repaint();
                if (nodeInfo.equals("Leaf2"))
                    rightPanel = new JPanel();
                    rightPanel.add(Jbt2);
                    Main.main_Frame.remove(rightPane);
                    rightPane = new JScrollPane(rightPanel);
                    rightPane.setHorizontalScrollBarPolicy(JScrollPane.HORIZONTAL_SCROLLBAR_ALWAYS);
                    rightPane.setVerticalScrollBarPolicy(JScrollPane.VERTICAL_SCROLLBAR_ALWAYS);
                    Main.main_Frame.add(rightPane, rightGBC);
                    Main.main_Frame.validate();
                    Main.main_Frame.repaint();
        DefaultTreeCellRenderer renderer = (DefaultTreeCellRenderer) tree.getCellRenderer();
        tree.setRowHeight(30);
        renderer.setLeafIcon(new ImageIcon("blue-ball.gif"));
        renderer.setOpenIcon(new ImageIcon("red-ball.gif"));
        renderer.setClosedIcon(new ImageIcon("yellow-ball.gif"));
        renderer.setFont(new Font("Monospaced",Font.BOLD|Font.ITALIC,15));
        renderer.setTextNonSelectionColor(Color.blue);
        renderer.setTextSelectionColor(Color.white);
        renderer.setBackgroundNonSelectionColor(Color.white);
        renderer.setBackgroundSelectionColor(Color.gray);
        renderer.setBorderSelectionColor(Color.lightGray);
        leftPanel.add(tree);
        add(leftPane, leftGBC);
        add(rightPane, rightGBC);
    private JPanel leftPanel;
    private JPanel rightPanel;
    private JScrollPane leftPane;
    private JScrollPane rightPane;
    private GridBagConstraints leftGBC;
    private GridBagConstraints rightGBC;
    private JButton Jbt1 = new JButton("Button1");
    private JButton Jbt2 = new JButton("Button2");
    private JLabel label = new JLabel("Enter your message below");
    private JTextArea jta = new JTextArea(10,15);
    private JButton Jbt3 = new JButton("Button3");
    private JButton Jbt4 = new JButton("Button4");
}