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javaswingword-wrapjava-7

Strange text wrapping with styled text in JTextPane with Java 7

I have two different editors using JTextPane with strange bugs in Java 7 that did not occur with the previous JVM versions. It happens with long lines containing styled text or components.

Here is an example demonstrating this bug. In this example, the default style is applied for all the text each time a character is inserted. I tested it with the JDK 1.7.0_04.

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

public class BugWrapJava7 extends JFrame {

    JTextPane jtp;
    StyledDocument doc;

    public BugWrapJava7() {
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        setLayout(new BorderLayout());
        jtp = new JTextPane();
        add(jtp, BorderLayout.CENTER);
        jtp.setText("\ntype some text in the above empty line and check the wrapping behavior");
        doc = jtp.getStyledDocument();
        doc.addDocumentListener(new DocumentListener() {
            public void insertUpdate(DocumentEvent e) {
                insert();
            }
            public void removeUpdate(DocumentEvent e) {
            }
            public void changedUpdate(DocumentEvent e) {
            }
        });
        setSize(200, 200);
        setVisible(true);
    }
    public void insert() {
        SwingUtilities.invokeLater(new Runnable() {
            public void run() {
                Style defaultStyle = jtp.getStyle(StyleContext.DEFAULT_STYLE);
                doc.setCharacterAttributes(0, doc.getLength(), defaultStyle, false);
            }
        });
    }
    public static void main(String[] args) {
        new BugWrapJava7();
    }
}

My question is : is there something wrong in my code, or is it indeed a new bug introduced in Java 7 ? And if it is a new JVM bug, is there a workaround ?

It might be related to question 8666727, but the problem here lies in the wrong wrapping rather than the appearance of a scrollbar.

Solution

  • for futures readers, bug is still present in JDK 1.7.0_04.,

    comparing Java7 and with stable Java6,

    enter image description here<------ Java7 v.s. Java6 --->enter image description here

    enter image description here<------ Java7 v.s. Java6 --->enter image description here

    enter image description here<------ Java7 v.s. Java6 --->enter image description here

    enter image description here <------ Java7 v.s. Java6 ---> enter image description here

    from code

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

public class BugWrapJava7 {

    private JFrame frame = new JFrame();
    private JTextPane jtp;
    private StyledDocument doc;

    public BugWrapJava7() {
        jtp = new JTextPane();
        jtp.setText("\ntype some text in the above empty line and check the wrapping behavior");
        doc = jtp.getStyledDocument();
        doc.addDocumentListener(new DocumentListener() {

            public void insertUpdate(DocumentEvent e) {
                insert();
            }

            public void removeUpdate(DocumentEvent e) {
                insert();
            }

            public void changedUpdate(DocumentEvent e) {
                insert();
            }

            public void insert() {
                SwingUtilities.invokeLater(new Runnable() {

                    public void run() {
                        Style defaultStyle = jtp.getStyle(StyleContext.DEFAULT_STYLE);
                        doc.setCharacterAttributes(0, doc.getLength(), defaultStyle, false);
                    }
                });
            }
        });
        JScrollPane scroll = new JScrollPane(jtp);
        scroll.setPreferredSize(new Dimension(200, 200));
        frame.add(scroll);
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.pack();
        frame.setVisible(true);
    }

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

            public void run() {
                BugWrapJava7 bugWrapJava7 = new BugWrapJava7();
            }
        });
    }
}