JScrollPane on JTextPane with GridBagLayout

Question

I am havign problem setting a scrollbar on a JTextPane. All I want. I want to add just buttons in one column from top to bottom, and I want the scrollbar so I can see all the buttons. I need to use GridBagLayout on the JTextPane. below is a simplified version of my code...anyone plz help..
public class ScrollTestMain {
public static void main(String[] args) {
JFrame frame=new JFrame("test");
JTextPane tp = new JTextPane();
JScrollPane sp=new JScrollPane(tp);
GridBagLayout gridbag=new GridBagLayout();
GridBagConstraints c=new GridBagConstraints();
tp.setLayout(gridbag);
c.weightx=100;
c.weighty=100;
for (int i=0;i<16;i++) {
c.gridx=0;
c.gridy=i;
JButton button =new JButton("button"+i);
gridbag.setConstraints(button,c);
System.out.println("for loop "+i);
tp.insertComponent(button);
frame.setSize(200,200);
frame.setVisible(true);
frame.getContentPane().add(sp, BorderLayout.CENTER);
tp.setEditable(false);
frame.show();
I want the buttons to be like:
button0
button1
button2
button3
button4
and the vertical scrollbar so I can scrolldown to see all the buttons.

Answer 1

From the "An Example of Using a Text Pane" section on the page How to Use Editor Panes and Text Panes in the java tutorial.
import java.awt.*;
import javax.swing.*;
import javax.swing.text.*;
public class TextPaneTest
    public static void main(String[] args)
        String newline = "\n";
        String[] initString = new String[8];
        String[] initStyles = new String[8];
        for(int j = 0; j < 8; j++)
            initString[j] = " " + newline;
            initStyles[j] = "button" + j;
        JTextPane textPane = new JTextPane();
        StyledDocument doc = textPane.getStyledDocument();
        addStylesToDocument(doc);
        try
            for(int j = 0; j < initString.length; j++)
                doc.insertString(doc.getLength(), initString[j],
                                 doc.getStyle(initStyles[j]));
        catch(BadLocationException ble)
            System.out.println("unable to init text");
        JScrollPane scrollPane = new JScrollPane(textPane);
        JFrame f = new JFrame();
        f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        f.getContentPane().add(scrollPane);
        f.setSize(400,400);
        f.setLocation(200,200);
        f.setVisible(true);
    private static void addStylesToDocument(StyledDocument doc)
        Style def = StyleContext.getDefaultStyleContext().
                        getStyle(StyleContext.DEFAULT_STYLE);
        Style space = doc.addStyle("space", def);
        StyleConstants.setSpaceAbove(space, 40f);
        StyleConstants.setLeftIndent(space, 75f);
        doc.setLogicalStyle(0, space);
        for(int j = 0; j < 8; j++)
            Style s = doc.addStyle("button" + j, space);
            JButton button = new JButton("button " + j);
            button.setCursor(Cursor.getDefaultCursor());
            button.setMargin(new Insets(5,5,5,5));
            button.setActionCommand("button " + j);
            //button1.addActionListener();
            StyleConstants.setComponent(s, button);
}