Insertion of icons into JTextPane

Question

Hello!
I am trying to insert icons into JTextPane object, and I got a problem.
My partial code is as follows...
StyleConstants.setIcon(s, icnIcons);
doc.insertString(doc.getLength(), "I", doc.getStyle("icon"));
doc.insertString(doc.getLength(), "I", doc.getStyle("icon"));
In the above code, s is an object of Style, and icnIcons is an object of ImageIcon, and doc is an object of StyledDocument.
And the style, s, is registered with a name, "icon".
If I execute the above code, then only one icon is displayed. But the length of the text is increased by 2.(I check this using doc.getLength() method.)
So, I make a little change to the above code like the following:
StyleConstants.setIcon(s, icnIcons);
doc.insertString(doc.getLength(), "I\n", doc.getStyle("icon")); //changed
doc.insertString(doc.getLength(), "I", doc.getStyle("icon"));
I just add "\n". And the second code is working, and displays two icons.
But the two icons are on the separate line.
And if I use two different icons, that is, two different styles, in the first code segment, then it works and shows the two icons on the same line, though I didn't use the "\n".
Why does this happen?
I am so confused. Please help me.
Thanks for every body!
Regards

Answer 1

import java.awt.*;
import java.awt.event.*;
import java.awt.image.BufferedImage;
import java.io.*;
import javax.imageio.ImageIO;
import javax.swing.*;
import javax.swing.text.*;
public class IconPane {
    private void showTest(BufferedImage[] images) throws IOException {
        JTextPane textPane = new JTextPane();
        // Add some content.
        File file = new File("IconPane.java");
        BufferedReader br = new BufferedReader(
                            new InputStreamReader(
                            new FileInputStream(file)));
        textPane.read(br, file);
        br.close();
        // Make up a couple of styles.
        int pos1 = 875, pos2 = 876;
        StyledDocument doc = textPane.getStyledDocument();
        Style style = textPane.addStyle("icon1", null);
        StyleConstants.setIcon(style, new ImageIcon(images[0]));
        // Set  icons.
        doc.setCharacterAttributes(pos1, 1, style, false);
        style = textPane.addStyle("icon2", null);
        StyleConstants.setIcon(style, new ImageIcon(images[1]));
        doc.setCharacterAttributes(pos2, 1, style, false);
        // Add the icons again with the insertString method.
        addContent(doc);
        // Show me.
        JScrollPane scrollPane = new JScrollPane(textPane);
        scrollPane.setPreferredSize(new Dimension(500,400));
        textPane.addMouseMotionListener(mouseInput);
        JOptionPane.showMessageDialog(null, scrollPane, "",
                                      JOptionPane.PLAIN_MESSAGE);
    private void addContent(StyledDocument doc) {
        int pos1 = 1667, pos2 = 1669;
        try {
            // Try inserting icons with insertString.
            doc.insertString(pos1, " ", doc.getStyle("icon1"));
            doc.insertString(pos2, " ", doc.getStyle("icon2"));
        } catch(BadLocationException e) {
            System.out.printf("bad location error: %s%n", e.getMessage());
    public static void main(String[] args) throws IOException {
        String[] ids = { "--g--", "---h-" };
        BufferedImage[] images = new BufferedImage[ids.length];
        for(int j = 0; j < images.length; j++)
            images[j] = ImageIO.read(new File("images/geek" + ids[j] + ".gif"));
        new IconPane().showTest(images);
    private MouseMotionAdapter mouseInput = new MouseMotionAdapter() {
        public void mouseMoved(MouseEvent e) {
            int pos = ((JTextComponent)e.getSource()).viewToModel(e.getPoint());
            System.out.println(String.valueOf(pos));
}