Problems with layout manager

Question

hello,
In the code below, no matter how much i incerase the size of
the top_pane object i can never get the scroll panel to move down
visually. I would like the scroll panel to be centerd on the
right side. I was trying to do this by adding a panel at the top
and bottom both 100 in height and then put the scroll panel
between them with a height of 400..this is not working :)
any suggestions or help appreciated,
jd
the code...
import javax.swing.JTree;
import java.net.URL;
import java.io.IOException;
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
import java.io.File;
import java.util.Vector;
import javax.swing.tree.*;
import javax.swing.event.*;
public class jd_back2{
     //Globals
      JPanel main_pane = new JPanel();
      JPanel command_panel = new JPanel();
      JPanel tree_pane = new JPanel();
      JPanel bottom_pane = new JPanel();
      JPanel scroller_pane = new JPanel();
      JPanel top_pane = new JPanel();
      JButton add = new JButton("Add");
      JButton remove = new JButton("Remove");
      JScrollPane picked_scroller = new JScrollPane(tree_pane);
      JFileChooser chooser = new JFileChooser();
      DefaultMutableTreeNode root_node = new DefaultMutableTreeNode("Files and Dirs to Backup");
      DefaultTreeModel treeModel = new DefaultTreeModel(root_node);
      JTree tree = new JTree(treeModel);
      String what;     
     public Component makeContent(){
          main_pane.setLayout(new BorderLayout());
          add.addMouseListener(new command_listner());
          remove.addMouseListener(new command_listner());
          makeTree();
          makeSelector();
          command_panel.add(add);
          command_panel.add(remove);
          picked_scroller.setPreferredSize(new java.awt.Dimension(200,300));
          picked_scroller.setVerticalScrollBarPolicy(javax.swing.JScrollPane.VERTICAL_SCROLLBAR_ALWAYS);
          picked_scroller.getViewport().setBackground(new java.awt.Color(255, 255, 255));
          picked_scroller.setBackground(new java.awt.Color(255, 255, 255));
          tree_pane.setBackground(new java.awt.Color(255, 255, 255));
          top_pane.setSize(new java.awt.Dimension(800,300));
          top_pane.setBackground(new java.awt.Color(255, 255, 255));
          tree_pane.add(tree); // tree_pane is added to picked_scroller above
          scroller_pane.add(picked_scroller);
          main_pane.add(top_pane, BorderLayout.NORTH);
          main_pane.add(scroller_pane, BorderLayout.EAST);
          main_pane.add(command_panel, BorderLayout.WEST);
          return main_pane;          
     public  void makeSelector(){
               chooser.setFileSelectionMode(2);
               chooser.setMultiSelectionEnabled(true);
               //chooser.setControlButtonsAreShown(false);
     public void makeTree(){
          tree.getSelectionModel().setSelectionMode(TreeSelectionModel.SINGLE_TREE_SELECTION);          
          tree.addTreeSelectionListener(new TreeSelectionListener() {
               public void valueChanged(TreeSelectionEvent e){
                    what = tree.getSelectionPath().toString();
                    System.out.println(what);
     public class command_listner extends MouseAdapter{
         public void mouseClicked(java.awt.event.MouseEvent evt){
              Object source = evt.getSource();
              if(source == add){
                   int returnVal = chooser.showOpenDialog(main_pane);
                   if (returnVal == JFileChooser.APPROVE_OPTION) {
                        File[] file = chooser.getSelectedFiles();
              if(source == remove){
                   System.out.println("Remove Clicked");
     public static void main(String[] args) {
        try {
            UIManager.setLookAndFeel(
                UIManager.getCrossPlatformLookAndFeelClassName());
        } catch (Exception e) {}
        JFrame frame = new JFrame("SwingApplication");
        jd_back2 app = new jd_back2(); // this concerns me
        Component contents = app.makeContent();
        frame.getContentPane().add(contents, BorderLayout.CENTER);
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.pack();
        frame.setSize(new java.awt.Dimension(800,600));
        frame.setLocation(100,50);
        frame.setVisible(true);
}

Answer 1

Use TableLayout manger it will make your life easier, atleast it has made mine life lot easier.
I have changed your code to use Tablelayout manager. You need TableLayout.jar to run it. It is available from http://java.sun.com/products/jfc/tsc/articles/tablelayout/
import java.awt.BorderLayout;
import java.awt.Component;
import java.awt.event.MouseAdapter;
import javax.swing.JButton;
import javax.swing.JFileChooser;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTree;
import javax.swing.UIManager;
import javax.swing.event.TreeSelectionEvent;
import javax.swing.event.TreeSelectionListener;
import javax.swing.tree.DefaultMutableTreeNode;
import javax.swing.tree.DefaultTreeModel;
import javax.swing.tree.TreeSelectionModel;
import layout.TableLayout;
public class jd_back2 {
     //Globals           
     JPanel main_pane = new JPanel();
     JPanel command_panel = new JPanel();
     JPanel tree_pane = new JPanel();
     JPanel bottom_pane = new JPanel();
     JPanel scroller_pane = new JPanel();
     JPanel top_pane = new JPanel();
     JButton add = new JButton("Add");
     JButton remove = new JButton("Remove");
     JScrollPane picked_scroller = new JScrollPane(tree_pane);
     JFileChooser chooser = new JFileChooser();
     DefaultMutableTreeNode root_node =
          new DefaultMutableTreeNode("Files and Dirs to Backup");
     DefaultTreeModel treeModel = new DefaultTreeModel(root_node);
     JTree tree = new JTree(treeModel);
     String what;
     public Component makeContent() {
          add.addMouseListener(new command_listner());
          remove.addMouseListener(new command_listner());
          makeTree();
          makeSelector();
          command_panel.add(add);
          command_panel.add(remove);
          picked_scroller.setPreferredSize(new java.awt.Dimension(200, 300));
          picked_scroller.setVerticalScrollBarPolicy(
               javax.swing.JScrollPane.VERTICAL_SCROLLBAR_ALWAYS);
          picked_scroller.getViewport().setBackground(
               new java.awt.Color(255, 255, 255));
          picked_scroller.setBackground(new java.awt.Color(255, 255, 255));
          tree_pane.setBackground(new java.awt.Color(255, 255, 255));
          top_pane.setSize(new java.awt.Dimension(800, 300));
          top_pane.setBackground(new java.awt.Color(255, 255, 255));
          tree_pane.add(tree);
          // tree_pane is added to picked_scroller above          
          scroller_pane.add(picked_scroller);
          double[][] size = {{450,TableLayout.FILL},{125,TableLayout.FILL,50}};
          TableLayout layout = new TableLayout(size);
          main_pane.setLayout(layout);
          main_pane.add(scroller_pane, "1,1");
          main_pane.add(command_panel, "0,0");
          return main_pane;
     public void makeSelector() {
          chooser.setFileSelectionMode(2);
          chooser.setMultiSelectionEnabled(true);
          //chooser.setControlButtonsAreShown(false);     
     public void makeTree() {
          tree.getSelectionModel().setSelectionMode(
               TreeSelectionModel.SINGLE_TREE_SELECTION);
          tree.addTreeSelectionListener(new TreeSelectionListener() {
               public void valueChanged(TreeSelectionEvent e) {
                    what = tree.getSelectionPath().toString();
                    System.out.println(what);
     public class command_listner extends MouseAdapter {
          public void mouseClicked(java.awt.event.MouseEvent evt) {
               Object source = evt.getSource();
               if (source == add) {
                    int returnVal = chooser.showOpenDialog(main_pane);
                    if (returnVal == JFileChooser.APPROVE_OPTION) {
               if (source == remove) {
                    System.out.println("Remove Clicked");
     public static void main(String[] args) {
          try {
               UIManager.setLookAndFeel(
                    UIManager.getCrossPlatformLookAndFeelClassName());
          } catch (Exception e) {
          JFrame frame = new JFrame("SwingApplication");
          jd_back2 app = new jd_back2();
          // this concerns me       
          Component contents = app.makeContent();
          frame.getContentPane().add(contents, BorderLayout.CENTER);
          frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
          frame.pack();
          frame.setSize(new java.awt.Dimension(800, 600));
          frame.setLocation(100, 50);
          frame.setVisible(true);
}