JTextPane doesn't display JScrollPane and doesn't Wrap Text

问题

I need to display links so I'm using JTextPane with setContentType. However, the content doesn't wrap and there's no scroll. The content of JTextPane will be returned from a RSS feed. Here's the full code:

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

class Main extends JFrame
{
    JFrame frame;
    JTabbedPane tabbedPane;
    JPanel home, news;      

    public Main()
    {
        setTitle("My Title" ); 
        setSize( 900, 600 ); 
        setLocationRelativeTo(null); 
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); 

        home(); 
        news(); 

        tabbedPane = new JTabbedPane(); 
        tabbedPane.addTab( " Home", home ); 
        tabbedPane.addTab( "News", news ); 

        JPanel framePanel = new JPanel();
        framePanel.setLayout(new BorderLayout());       
        framePanel.add( tabbedPane, BorderLayout.CENTER );
        getContentPane().add( framePanel );     

    }


    public void home() 
    {       
        home = new JPanel();
        // some stuffs here
    }


    public void news()
    {
        news = new JPanel();

        JTextPane newsTextPane = new JTextPane(); 
        newsTextPane.setContentType("text/html");
        newsTextPane.setEditable(false); 

        JScrollPane scrollPane = new JScrollPane(newsTextPane);     
        scrollPane.setVerticalScrollBarPolicy(javax.swing.ScrollPaneConstants.VERTICAL_SCROLLBAR_ALWAYS);
        news.add(scrollPane);   

        RSS reader = RSS .getInstance();
        reader.writeNews();             

        String rssNews = reader.writeNews();
        newsTextPane.setText(rssNews);
    }   

    public static void main( String args[] )
    {

        RSS reader = RSS.getInstance();
        reader.writeNews();

        Main mainFrame  = new Main();
        mainFrame.setVisible( true );   
        mainFrame.setDefaultCloseOperation( EXIT_ON_CLOSE );
        }
}

My result:

回答1:

I just used your code and it does not cause any problems:

import javax.swing.JFrame;
import javax.swing.JScrollPane;
import javax.swing.JTextPane;
import javax.swing.SwingUtilities

public class TestScrolling {

    public static void main(String[] args) {
            SwingUtilities.invokeLater(new Runnable() {
                 public void run() {
                  initUI();
                 });
    }

    public static void initUI() {
        StringBuilder sb = new StringBuilder();
        for (int i = 0; i < 100; i++) {
            sb.append("loads loads loads loads of text here ");
        }
        JFrame frame = new JFrame();
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        JTextPane newsTextPane = new JTextPane();
        newsTextPane.setContentType("text/html");
        newsTextPane.setEditable(false);
        newsTextPane.setText(sb.toString());

        JScrollPane scrollPane = new JScrollPane(newsTextPane);
        scrollPane.setVerticalScrollBarPolicy(
                  javax.swing.ScrollPaneConstants.VERTICAL_SCROLLBAR_AS_NEEDED);
        frame.add(scrollPane);
        frame.setSize(300, 200);
        frame.setVisible(true);
     }
}

EDIT:

You have to force somehow the width of the scrollPane. In my example it is done implicitly by adding the scrollpane to the content pane of the frame, which by default uses the BorderLayout. In your case, you used a FlowLayout which allocates the preferred size of the scrollpane which is about the preferred size of the JTextPane.

回答2:

Are you using a panel or something around your JScrollPane?

Taking the sscc of @Guillaume Polet with innapropriate size the example won't work :

import java.awt.Dimension;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTextPane;

public class TestScrolling {

    public static void main(String[] args) {
        StringBuilder sb = new StringBuilder();
        for (int i = 0; i < 100; i++) {
            sb.append("loads loads loads loads of text here ");

        }
        JFrame frame = new JFrame();
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        JTextPane newsTextPane = new JTextPane();
        newsTextPane.setContentType("text/html");
        newsTextPane.setEditable(false);
        newsTextPane.setText(sb.toString());
        JScrollPane scrollPane = new JScrollPane(newsTextPane);
        scrollPane.setVerticalScrollBarPolicy(javax.swing.ScrollPaneConstants.VERTICAL_SCROLLBAR_AS_NEEDED);
        JPanel pan = new JPanel();
        pan.setMinimumSize(new Dimension(500,500));
        pan.add(scrollPane);
        frame.add(pan);
        frame.setSize(500, 500);
        frame.setVisible(true);
    }
}

I see your adding your JscrollPane to panel. Can you provide the creation/modification you made on that panel and where this panel is used?

来源：https://stackoverflow.com/questions/10461087/jtextpane-doesnt-display-jscrollpane-and-doesnt-wrap-text

标签

java

swing

jtextpane