JTextPane - fit size to its content

Iaroslav Baranov Published at Dev

Iaroslav Baranov

What I have -

What I need -

Code:

JFrame frame = new JFrame();
JPanel panel = new JPanel();
JTextPane pane = new JTextPane();
pane.setText("Long string Long string Long string Long string Long string Long string");
panel.setLayout(new BoxLayout(panel, BoxLayout.PAGE_AXIS));
panel.add(pane);
panel.add(new JButton("Button"));
frame.add(panel);
frame.show();

If I do frame.pack(), I get very long window without word wrap!

Andrew Thompson

For any HTML aware Swing component, width can be set for the body using HTML styles (CSS). This in turn will determine the number of lines to render and, from that, the preferred height of the text component. Setting the width in CSS avoids the need to compute where line breaks should occur in (or the best size of) the component.

More generally, see How to Use HTML in Swing Components.

E.G.

import javax.swing.*;

public class FixedWidthLabel {

    public static void main(String[] srgs) {
        final String s = "Lorem ipsum dolor sit amet, consectetur adipiscing elit. Aenean eu nulla urna. Donec sit amet risus nisl, a porta enim. Quisque luctus, ligula eu scelerisque gravida, tellus quam vestibulum urna, ut aliquet sapien purus sed erat. Pellentesque consequat vehicula magna, eu aliquam magna interdum porttitor. Class aptent taciti sociosqu ad litora torquent per conubia nostra, per inceptos himenaeos. Sed sollicitudin sapien non leo tempus lobortis. Morbi semper auctor ipsum, a semper quam elementum a. Aliquam eget sem metus.";
        final String html1 = "<html><body style='width: ";
        final String html2 = "px'>";

        Runnable r = new Runnable() {

            @Override
            public void run() {
                JOptionPane.showMessageDialog(
                        null, new JLabel(html1 + "200" + html2 + s));
                JOptionPane.showMessageDialog(
                        null, new JLabel(html1 + "300" + html2 + s));
            }
        };
        SwingUtilities.invokeLater(r);
    }
}

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