4

First of all I hope it's not a problem I started a new topic. Tbh I don't have a clue how to ask a question based on an already answered one, so I made this.

I'm pretty new with Java and my problem is the following. I'm writing a little chat program and I'm using a JEditorPane with an HTMLEditorKit to display text in different colors, to display smileys, and display hyperlinks.

My problem is, and after some research I found out the problem might be due to Java7, I can't get the linewrap working properly. I want the text to word wrap and to wrap in the middle of Strings exceeding the width of the component. The word wrap works fine, but if someone types in a pretty long string the JEditorPane gets expanded and you need to resize the frame to get everything on screen, which is what I do not want to happen.

I've tried a few fixes for this problem, but they only allow letter wrap such that word wrap no longer works. Beside that, I want the user to be able to wrap his text by hitting Enter. For that I'm adding \n to the text and with the fixes this will no longer affect the result and everything's going to be displayed in one line.

I'm feeling like I've spent years in the web to find a solution but unitl now nothing worked for my case, especially since it appeared to be the same fix all the time. I hope you guys can help me.

This means in summary:

What I have:

  • Line wraps word in case of long strings separated by spaces
  • if you use Windows and your input contains line wraps created by hitting enter, they will also wrap
  • If you type in a very long string without spaces, the panel gets expanded and you need to resize the frame
  • HTML formatting allows me to display different colors as well as hyperlinks and emoticons

What I need:

  • Word wrap behaviour like it is at the moment in case it is possible but letter wrap ONLY in case of long strings not separated by spaces to prevent the panel from expanding.
  • Manually added line wraps made by hitting ENTER in the input area or if I copy an pre formatted text into the input panel
  • HTML formatting like I have already

What I've tried and what didn't help:

jtextpane doesn't wrap text and JTextPane is not wrapping text

Here is some code to try it yourself. In the bottom left is an input area to type in some text. You can also add line wraps by hitting enter. After clicking on the button you will see the text in the area above.

import java.awt.BorderLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.KeyEvent;
import java.awt.event.KeyListener;
import java.io.IOException;

import javax.swing.BorderFactory;
import javax.swing.JButton;
import javax.swing.JEditorPane;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JTextArea;
import javax.swing.border.TitledBorder;
import javax.swing.text.BadLocationException;
import javax.swing.text.html.HTMLDocument;
import javax.swing.text.html.HTMLEditorKit;
import javax.swing.text.html.StyleSheet;

@SuppressWarnings("serial")
public class LineWrapTest extends JFrame implements ActionListener, KeyListener {

private JButton btnSend;
private JTextArea textAreaIn;
private JEditorPane textAreaOut;
private HTMLEditorKit kit;
private HTMLDocument doc;

public LineWrapTest() {

    this.setSize(600, 500);
    this.setDefaultCloseOperation(EXIT_ON_CLOSE);
    this.setLocationRelativeTo(null);
    this.setTitle("Linewrap Test");
}

/**
 * Not important for problem
 */
public void paintScreen() {

    this.setLayout(new BorderLayout());

    this.add(this.getPanelOut(), BorderLayout.CENTER);
    this.add(this.getPanelIn(), BorderLayout.SOUTH);

    this.textAreaIn.requestFocusInWindow();
    this.setVisible(true);
}

/**
 * Not important for problem
 * 
 * @return panelOut
 */
private JPanel getPanelOut() {

    JPanel panelOut = new JPanel();
    panelOut.setLayout(new BorderLayout());

    this.textAreaOut = new JEditorPane();
    this.textAreaOut.setEditable(false);
    this.textAreaOut.setContentType("text/html");

    this.kit = new HTMLEditorKit();
    this.doc = new HTMLDocument();

    StyleSheet styleSheet = this.kit.getStyleSheet();
    this.kit.setStyleSheet(styleSheet);

    this.textAreaOut.setEditorKit(this.kit);
    this.textAreaOut.setDocument(this.doc);

    TitledBorder border = BorderFactory.createTitledBorder("Output");
    border.setTitleJustification(TitledBorder.CENTER);

    panelOut.setBorder(border);
    panelOut.add(this.textAreaOut);

    return panelOut;
}

/**
 * Not important for problem
 * 
 * @return panelIn
 */
private JPanel getPanelIn() {

    JPanel panelIn = new JPanel();
    panelIn.setLayout(new BorderLayout());

    this.textAreaIn = new JTextArea();
    this.textAreaIn.setLineWrap(true);
    this.textAreaIn.setWrapStyleWord(true);

    TitledBorder border = BorderFactory.createTitledBorder("Input");
    border.setTitleJustification(TitledBorder.CENTER);

    panelIn.setBorder(border);
    panelIn.add(this.getBtnSend(), BorderLayout.EAST);
    panelIn.add(this.textAreaIn, BorderLayout.CENTER);

    return panelIn;
}

/**
 * Not important for problem
 * 
 * @return btnSend
 */
private JButton getBtnSend() {

    this.btnSend = new JButton("Send");
    this.btnSend.addActionListener(this);

    return this.btnSend;
}

private void append(String text) {

    try {
        this.kit.insertHTML(this.doc, this.doc.getLength(), text, 0, 0, null);
    } catch (BadLocationException e) {
        e.printStackTrace();
    } catch (IOException e) {
        e.printStackTrace();
    }
}

private String getHTMLText() {

    String txtIn = this.textAreaIn.getText().trim().replaceAll(SEPARATOR, "<br/>");

    StringBuffer htmlBuilder = new StringBuffer();

    htmlBuilder.append("<HTML>");
    htmlBuilder.append(txtIn);
    htmlBuilder.append("</HTML>");

    return htmlBuilder.toString();
}

@Override
public void actionPerformed(ActionEvent e) {

    if (e.getSource() == this.btnSend) {
        this.append(this.getHTMLText());
        this.textAreaIn.setText("");
        this.textAreaIn.requestFocusInWindow();
    }
}

public static void main(String[] args) {

    LineWrapTest test = new LineWrapTest();
    test.paintScreen();
}

@Override
public void keyPressed(KeyEvent e) {

    if (e.getKeyCode() == KeyEvent.VK_ENTER)
        if (!this.textAreaIn.getText().trim().isEmpty())
            this.textAreaIn.setText(this.textAreaIn.getText() + SEPARATOR);
}

@Override
public void keyReleased(KeyEvent e) {
}

@Override
public void keyTyped(KeyEvent e) {
}
}

UPDATE: base on some parts of http://java-sl.com/tip_java7_text_wrapping_bug_fix.html

Somehow I figured it out to step a bit closer to my goal. I've tried to combine the fix for an HTMLEditorKit with an StlyedEditorKit Fix. But I have to be honest, I don't have any clue what I actually did there :( The sad thing is, the manual line wraping does no longer work with this as a replacement of the HTMLEditorKit. Maybe you can use this as a base for some better implementation.

To use it in my example just create a new class in the project with the CustomEditorKit and replace the HTMLEditorKit in the example with this CustomEditorKit. You will notice that word and letter wrapping works now, but if you hit ENTER to get your own line wrap this change will no longer appear in the output-panel and everything will be displayed in one line. Another strange problem of it is, that if you resize the frame the lines will sometimes lay on each other.

import javax.swing.SizeRequirements;
import javax.swing.text.Element;
import javax.swing.text.View;
import javax.swing.text.ViewFactory;
import javax.swing.text.html.HTMLEditorKit;
import javax.swing.text.html.InlineView;
import javax.swing.text.html.ParagraphView;

@SuppressWarnings("serial")
public class CustomEditorKit extends HTMLEditorKit {

@Override
public ViewFactory getViewFactory() {

    return new HTMLFactory() {
        @Override
        public View create(Element e) {
            View v = super.create(e);
            if (v instanceof InlineView) {
                return new InlineView(e) {
                    @Override
                    public int getBreakWeight(int axis, float pos, float len) {
                        return GoodBreakWeight;
                    }

                    @Override
                    public View breakView(int axis, int p0, float pos, float len) {
                        if (axis == View.X_AXIS) {
                            this.checkPainter();
                            this.removeUpdate(null, null, null);
                        }
                        return super.breakView(axis, p0, pos, len);
                    }
                };
            }
            else if (v instanceof ParagraphView) {
                return new ParagraphView(e) {
                    @Override
                    protected SizeRequirements calculateMinorAxisRequirements(int axis, SizeRequirements r) {
                        if (r == null) {
                            r = new SizeRequirements();
                        }
                        float pref = this.layoutPool.getPreferredSpan(axis);
                        float min = this.layoutPool.getMinimumSpan(axis);
                        // Don't include insets, Box.getXXXSpan will include them. 
                        r.minimum = (int) min;
                        r.preferred = Math.max(r.minimum, (int) pref);
                        r.maximum = Integer.MAX_VALUE;
                        r.alignment = 0.5f;
                        return r;
                    }

                };
            }
            return v;
        }
    };
    }
}
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BenGe89
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  • Ok so here is what is happening for me with the above code. The JTextArea wraps perfectly. Long Strings and words both wrap to the next line. The JEditorPane wraps words until it is extended by a long string. Then to word wrap, the sentence has to be longer than the string that extended the component. Hitting enter does not cause custom wrap at present moment, using the universal line separator. What you want: Wrapping of the JEditorPane for long strings, without adding spaces, just like the JTextArea does, so that it isn't expanded. Also, by hitting enter a custom wrap in the JEpane. – Patrick Sebastien Jul 09 '13 at 16:38

2 Answers2

6

OK! So, I finally got everything you were having problems with working. It took some research and a lot of trial and error, but here it is:

Here is what I did:

  • Put the JEditorPane in a JScrollPane so you can scroll up and down as the message gets bigger
  • Added a custom word wrap. The custom word wrap will wrap words and long words in the desired location of the word. You were right, this is a bug with the current version of Java. http://bugs.sun.com/view_bug.do?bug_id=7125737
  • Added the ability for the user to wrap to a new line by hitting Enter. This interfered with the custom word wrap though, so you may not like how I achieved this. In the code example I suggest other options.
  • Preserved your HTMLDocument abilities. I was tempted to not do this, but I found work arounds so that it could be preserved.
  • The application still uses a JEditorPane, but you could switch it to a JTextPane if you want. I tried both and they were both functional.

So here is the code. It's a bit long and you may wish to change it based on your preferences. I commented where I made changes and tried to explain them.

import java.awt.BorderLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.KeyEvent;
import java.awt.event.KeyListener;
import java.io.IOException;

import javax.swing.BorderFactory;
import javax.swing.JButton;
import javax.swing.JEditorPane;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTextArea;
import javax.swing.KeyStroke;
import javax.swing.SizeRequirements;
import javax.swing.border.TitledBorder;
import javax.swing.text.*;
import javax.swing.text.html.HTMLDocument;
import javax.swing.text.html.HTMLEditorKit;
import javax.swing.text.html.InlineView;
import javax.swing.text.html.StyleSheet;

@SuppressWarnings("serial")
public class LineWrapTest extends JFrame implements ActionListener, KeyListener {

    //This is the separator.
    private String SEPARATOR = System.getProperty("line.separator");
    private JButton btnSend;
    private JTextArea textAreaIn;
    private JEditorPane textAreaOut;
    private JScrollPane outputScrollPane;
    private HTMLEditorKit kit;
    private HTMLDocument doc;


    public LineWrapTest() {

        this.setSize(600, 500);
        this.setDefaultCloseOperation(EXIT_ON_CLOSE);
        this.setLocationRelativeTo(null);
        this.setTitle("Linewrap Test");
    }

    /**
     * Not important for problem
     */
    public void paintScreen() {

        this.setLayout(new BorderLayout());

        this.add(this.getPanelOut(), BorderLayout.CENTER);
        this.add(this.getPanelIn(), BorderLayout.SOUTH);

        this.textAreaIn.requestFocusInWindow();
        this.setVisible(true);
    }


    /**
     * Not important for problem
     * 
     * @return panelOut
     */
    private JPanel getPanelOut() {

        JPanel panelOut = new JPanel();
        panelOut.setLayout(new BorderLayout());

        this.textAreaOut = new JEditorPane();
        this.textAreaOut.setEditable(false);
        this.textAreaOut.setContentType("text/html");

        //I added this scroll pane.
        this.outputScrollPane = new JScrollPane(this.textAreaOut);

        /*
         * This is a whole whack of code.  It's a combination of two sources.
         * It achieves the wrapping you desire: by word and longgg strings
         * It is a custom addition to HTMLEditorKit
         */
        this.kit = new HTMLEditorKit(){
           @Override 
           public ViewFactory getViewFactory(){ 

               return new HTMLFactory(){ 
                   public View create(Element e){ 
                      View v = super.create(e); 
                      if(v instanceof InlineView){ 
                          return new InlineView(e){ 
                              public int getBreakWeight(int axis, float pos, float len) { 
                                  //return GoodBreakWeight;
                                  if (axis == View.X_AXIS) {
                                      checkPainter();
                                      int p0 = getStartOffset();
                                      int p1 = getGlyphPainter().getBoundedPosition(this, p0, pos, len);
                                      if (p1 == p0) {
                                          // can't even fit a single character
                                          return View.BadBreakWeight;
                                      }
                                      try {
                                          //if the view contains line break char return forced break
                                          if (getDocument().getText(p0, p1 - p0).indexOf(SEPARATOR) >= 0) {
                                              return View.ForcedBreakWeight;
                                          }
                                      }
                                      catch (BadLocationException ex) {
                                          //should never happen
                                      }  

                                  }
                                  return super.getBreakWeight(axis, pos, len);
                              } 
                              public View breakView(int axis, int p0, float pos, float len) { 
                                  if (axis == View.X_AXIS) {
                                      checkPainter();
                                      int p1 = getGlyphPainter().getBoundedPosition(this, p0, pos, len);
                                      try {
                                          //if the view contains line break char break the view
                                          int index = getDocument().getText(p0, p1 - p0).indexOf(SEPARATOR);
                                          if (index >= 0) {
                                              GlyphView v = (GlyphView) createFragment(p0, p0 + index + 1);
                                              return v;
                                          }
                                      }
                                      catch (BadLocationException ex) {
                                          //should never happen
                                      }

                                  }
                                  return super.breakView(axis, p0, pos, len);
                            } 
                          }; 
                      } 
                      else if (v instanceof ParagraphView) { 
                          return new ParagraphView(e) { 
                              protected SizeRequirements calculateMinorAxisRequirements(int axis, SizeRequirements r) { 
                                  if (r == null) { 
                                        r = new SizeRequirements(); 
                                  } 
                                  float pref = layoutPool.getPreferredSpan(axis); 
                                  float min = layoutPool.getMinimumSpan(axis); 
                                  // Don't include insets, Box.getXXXSpan will include them. 
                                    r.minimum = (int)min; 
                                    r.preferred = Math.max(r.minimum, (int) pref); 
                                    r.maximum = Integer.MAX_VALUE; 
                                    r.alignment = 0.5f; 
                                  return r; 
                                } 

                            }; 
                        } 
                      return v; 
                    } 
                }; 
            } 
        }; 

        this.doc = new HTMLDocument();

        StyleSheet styleSheet = this.kit.getStyleSheet();
        this.kit.setStyleSheet(styleSheet);

        this.textAreaOut.setEditorKit(this.kit);
        this.textAreaOut.setDocument(this.doc);

        TitledBorder border = BorderFactory.createTitledBorder("Output");
        border.setTitleJustification(TitledBorder.CENTER);

        panelOut.setBorder(border);

        //I changed this to add the scrollpane, which now contains
        //the JEditorPane
        panelOut.add(this.outputScrollPane);

        return panelOut;
    }

    /**
     * Not important for problem
     * 
     * @return panelIn
     */
    private JPanel getPanelIn() {

        JPanel panelIn = new JPanel();
        panelIn.setLayout(new BorderLayout());

        this.textAreaIn = new JTextArea();
        this.textAreaIn.setLineWrap(true);
        this.textAreaIn.setWrapStyleWord(true);

        //This disables enter from going to a new line.  Your key listener does that.
        this.textAreaIn.getInputMap().put(KeyStroke.getKeyStroke("ENTER"), "none");
        //For the key listener to work, it needs to be added to the component
        this.textAreaIn.addKeyListener(this);

        TitledBorder border = BorderFactory.createTitledBorder("Input");
        border.setTitleJustification(TitledBorder.CENTER);

        panelIn.setBorder(border);
        panelIn.add(this.getBtnSend(), BorderLayout.EAST);
        panelIn.add(this.textAreaIn, BorderLayout.CENTER);

        return panelIn;
    }

    /**
     * Not important for problem
     * 
     * @return btnSend
     */
    private JButton getBtnSend() {

        this.btnSend = new JButton("Send");
        this.btnSend.addActionListener(this);

        return this.btnSend;
    }


    private void append(String text) {

        try {
            this.kit.insertHTML(this.doc, this.doc.getLength(), text, 0, 0, null);
        } catch (BadLocationException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    private String getHTMLText() {
        //I tried to find a work around for this but I couldn't.  It could be done
        //by manipulating the HTMLDocument but it's beyond me.  Notice I changed
        //<br/> to <p/>.  For some reason, <br/> no longer went to the next line
        //when I added the custom wrap.  <p/> seems to work though.
        String txtIn = this.textAreaIn.getText().trim().replaceAll(SEPARATOR, "<p/>");

        //My IDE recommends you use StringBuilder instead, that's up to you.
        //I am not sure what the difference would be.
        StringBuffer htmlBuilder = new StringBuffer();

        htmlBuilder.append("<HTML>");
        htmlBuilder.append(txtIn);
        htmlBuilder.append("</HTML>");

        return htmlBuilder.toString();
    }

    @Override
    public void actionPerformed(ActionEvent e) {

        if (e.getSource() == this.btnSend) {
            this.append(this.getHTMLText());
            this.textAreaIn.setText("");
            this.textAreaIn.requestFocusInWindow();
        }
    }

    public static void main(String[] args) {
        LineWrapTest test = new LineWrapTest();
        test.paintScreen();
    }

    @Override
    public void keyPressed(KeyEvent e) {
        if (e.getKeyCode() == KeyEvent.VK_ENTER){
            if (!this.textAreaIn.getText().trim().isEmpty()) {
                //I made this work by defining the SEPARATOR.
                //You could use append(Separator) instead if you want.
                this.textAreaIn.setText(this.textAreaIn.getText() + SEPARATOR);
            }
        }
    }

    @Override
    public void keyReleased(KeyEvent e) {
    }

    @Override
    public void keyTyped(KeyEvent e) {
    }

}

Here are (most of) the links that I used to solve this problem:

Enabling word wrap in a JTextPane with HTMLDocument

Custom wrap is a combination of these two:

http://java-sl.com/tip_html_letter_wrap.html

http://java-sl.com/wrap.html

Deleting the keybind for JTextArea:

http://docs.oracle.com/javase/tutorial/uiswing/misc/keybinding.html

If you have any questions whatsoever, just comment below. I will answer them. I sincerely hope this solves your problems

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  • Hey Allan, thanks for your detailed answer. Especially the separator thing was new for me. But your fix does not help me. I don't have a problem with the word wrap or the scrollpane, I need both, the word an letter wrap. You wrote you had troubles with my code example, what went wrong? Its working for me :/ – BenGe89 Jul 09 '13 at 06:15
  • @BenGe89 Perhaps I misunderstood your question. Could you edit it to make it more clear, exactly what you need and what your problems are? When I ran your code, all that came up was a blank window with a button on the bottom right. – Patrick Sebastien Jul 09 '13 at 11:58
  • I've edited the OP, hope it makes things more clear now. I've also added some borders to the example and an short description for it in the OP. I have also deleted the part with the scrollbar since it doesn't have much to do with the problem, sorry for misleading with it. To make it short, I want what I already have but with the Java6 behaviour wrap word if possible, else wrap letter for an HTMLEditorKit. The example does only show the problem. I've not yet added the line.separator since the replacement didn't work. By hitting Enter I want the programm to create an own line wrap. – BenGe89 Jul 09 '13 at 14:33
  • @BenGe89 Ok thanks for editing it. I will have a look and see if there is any solution I can come up with and edit my answer accordingly. If I can't figure it out I may have to delete my answer though. – Patrick Sebastien Jul 09 '13 at 15:36
  • Thank you very much! Really appreciate your help on this! In the meantime I've tried some things again. Not a great success but a small one was the combination of a fix for HTMLEditorKit and a StyledEditorKit. I've added it under my example, maybe you can take some information from this, I can't :/ I definitely need to dive deeper into Java ... BTW, do you know a better way to create own line wraps than I'm doing? Don't really like the "replace(String, String)" way, especially since it doesn't seem te work with the line.separator. – BenGe89 Jul 09 '13 at 16:37
  • @BenGe89 So I have done a full analysis of your application on pen and paper, so I feel that I understand the structure well. I have fixed some of the issues so far but there are still some things I need to take care of. I feel that I can fix it, but I do want to know: **Does it matter if you use a** `JEditorPane` **or a** `JTextPane` **, based on the link I provided to Oracle?** – Patrick Sebastien Jul 09 '13 at 17:10
  • I've done some tests and so far I cannot see any differences when using a JTextPane instead of a JEditorPane. So I guess it doesn't matter and as fas as I understand the TextPane oder EditorPane is more ore less some kind of container and the document is doing the job, isn't it? Long story short, I don't think it makes a difference. Thanks again! – BenGe89 Jul 09 '13 at 17:52
  • @BenGe89 Okie doke. See my answer. This should be what you are looking for. If you have any questions, let me know. I know i'm not supposed to say stuff like this, but I spent nearly 6-8 hours figuring this out, so if the answer works for you, when you get enough reputation, I would heartily love an upvote on my answer haha. – Patrick Sebastien Jul 09 '13 at 23:13
  • That's it! It works like a charm. Thank you very very much, you are my hero now. I tried replacing
    with

    in my CustomEditorKit and it worked as well, but I do have way more faith in your implementation so I'm rather using yours. I can't thank you enough. Regarding to the StringBuffer/Builder, afaik there is no real difference between those but StringBuffer is thread safe while the builder is not.
    – BenGe89 Jul 10 '13 at 06:21
1

A deadly better solution I found : The <br> is correctly handled by the HTMLEditorKit, but the Patrick Sebastien's post mentionned that it won't. It's because its ViewFactory threat all InlineView object as wrappable, but the BRView is also an InlineView. See my solution below:

class WrapColumnFactory extends HTMLEditorKit.HTMLFactory {

        @Override
        public View create(Element elem) {
            View v = super.create(elem);

            if (v instanceof LabelView) {

                // the javax.swing.text.html.BRView (representing <br> tag) is a LabelView but must not be handled
                // by a WrapLabelView. As BRView is private, check the html tag from elem attribute
                Object o = elem.getAttributes().getAttribute(StyleConstants.NameAttribute);
                if ((o instanceof HTML.Tag) && o == HTML.Tag.BR) {
                    return v;
                }

                return new WrapLabelView(elem);
            }

            return v;
        }
    }

    class WrapLabelView extends LabelView {

        public WrapLabelView(Element elem) {
            super(elem);
        }

        @Override
        public float getMinimumSpan(int axis) {
            switch (axis) {
                case View.X_AXIS:
                    return 0;
                case View.Y_AXIS:
                    return super.getMinimumSpan(axis);
                default:
                    throw new IllegalArgumentException("Invalid axis: " + axis);
            }
        }

    }
  • This is the best (simplest and also most comprehensive) solution I have found to the problem. I have componentized this solution as the [answer to a similar question](http://stackoverflow.com/a/31930559/2074605). – Parker Aug 10 '15 at 23:05