How to make the horizontal scroll bar appear in a JScrollPane that contains a JTextPane component

Question

I can't make the horizontal scrollbar appear. I've tried using JTextPane.setSize(), JTextPane.setPreferredSize() and no size method for JTextPane. I'm also using JScrollPane.setPreferredSize().

The vertical scroll bar appears, but the horizontal one doesn't.

Here is an example:

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;

public class Test {

    private int         textPaneWidth    = 500;
    private int         textPaneHeigth   = 200;
    private int         scrollPaneWidth  = 100;
    private int         scrollPaneHeigth = 100;
    private JTextPane   textPane;
    private JButton     button;
    private JFrame      frame;
    private JScrollPane scrollPane;

    public static void main(String[] args) {

        Test gui = new Test();
        gui.go();

    }

    private void go() {

        frame       = new JFrame("Test");
        button      = new JButton("button");
        textPane    = new JTextPane();
        scrollPane  = new JScrollPane(textPane, JScrollPane.VERTICAL_SCROLLBAR_ALWAYS, JScrollPane.HORIZONTAL_SCROLLBAR_ALWAYS);

        frame.setLayout(new FlowLayout());
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        button.addActionListener(new ButtonListener());
        textPane.setFont(new Font("Courier", Font.PLAIN, 12));

        // Sizes:
//        textPane.setSize(textPaneWidth, textPaneHeigth);                             // ???
//        textPane.setPreferredSize(new Dimension(textPaneWidth, textPaneHeigth));     // ???
        scrollPane.setPreferredSize(new Dimension(scrollPaneWidth, scrollPaneHeigth));

        frame.add(button);
        frame.add(scrollPane, BorderLayout.CENTER);
        frame.pack();
        frame.setVisible(true);

    }

    private class ButtonListener implements ActionListener {

        public void actionPerformed(ActionEvent event) {
             textPane.setText("==================================================================== \n" + 
                         "==================================================================== \n" +
                         "==================================================================== \n" +
                         "==================================================================== \n" +
                         "==================================================================== \n");
        }

    }
}

When the button is pressed, the string is added to the JTextPane. There is vertical scrolling, but no horizontal scrolling.

This is what I'm seeing after pressing the button:

What am I doing wrong?

Answer 1

seems like you need to extend JTextPane to avoid wrapping

https://forums.oracle.com/thread/1210688

class JTextWrapPane extends JTextPane {

    boolean wrapState = true;
    JTextArea j = new JTextArea();

    JTextWrapPane() {
        super();
    }

    public JTextWrapPane(StyledDocument p_oSdLog) {
        super(p_oSdLog);
    }


    public boolean getScrollableTracksViewportWidth() {
        return wrapState;
    }


    public void setLineWrap(boolean wrap) {
        wrapState = wrap;
    }


    public boolean getLineWrap(boolean wrap) {
        return wrapState;
    }
}  

EDIT:

//  instead of  private JTextPane jtp = new JTextPane( sdLog );
    private JTextWrapPane jtp = new JTextWrapPane( sdLog );
//and set LineWrap = (false):
        jtp.setLineWrap(false);