Demonstrates a text rendering bug on the OS X Java implementation.

java-text-rendering-bug

import javax.swing.*;
import javax.swing.event.DocumentEvent;
import javax.swing.event.DocumentListener;
import java.awt.*;
import java.awt.font.FontRenderContext;
import java.awt.font.LineBreakMeasurer;
import java.awt.font.TextAttribute;
import java.awt.font.TextLayout;
import java.awt.geom.AffineTransform;
import java.text.AttributedString;

public class TextRenderTest extends JFrame {

    private String text = "3sa";
    private JTextField field;

    public TextRenderTest() throws HeadlessException {
        super("Text Render Test");
        JPanel p = new JPanel(new BorderLayout());
        field = new JTextField(text);
        field.getDocument().addDocumentListener(new DocumentListener() {
            public void insertUpdate(DocumentEvent e) {
                fieldChanged();
            }

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

            public void changedUpdate(DocumentEvent e) {
                fieldChanged();
            }
        });
        p.add(field, BorderLayout.NORTH);
        p.add(new TextView(), BorderLayout.CENTER);
        p.setSize(400, 400);
        setContentPane(p);
        setLocationByPlatform(true);
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        setSize(800, 800);
        setVisible(true);
    }

    public static void main(String[] args) {
        new TextRenderTest();
    }

    public void fieldChanged() {
        text = field.getText();
        repaint();

    }

    public class TextView extends JComponent {
        public TextView() {
        }

        @Override
        protected void paintComponent(Graphics g) {
            Graphics2D g2 = (Graphics2D) g;
            g2.setColor(Color.WHITE);
            g2.fillRect(0, 0, TextView.this.getWidth(), TextView.this.getHeight());
            g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
            g2.setRenderingHint(RenderingHints.KEY_TEXT_ANTIALIASING, RenderingHints.VALUE_TEXT_ANTIALIAS_ON);
            if (text.length() == 0) {
                text = " ";
            }
            AttributedString attrString = new AttributedString(text);
            Font font = new Font("Verdana", Font.PLAIN, 400);
            font = font.deriveFont(font.getStyle(), font.getSize2D());
            attrString.addAttribute(TextAttribute.FONT, font);
            attrString.addAttribute(TextAttribute.FOREGROUND, Color.BLACK);
            LineBreakMeasurer measurer = new LineBreakMeasurer(attrString.getIterator(), new FontRenderContext(null, false, false));
            TextLayout layout = measurer.nextLayout(10000);
            AffineTransform trans = new AffineTransform();
            trans.translate(10, 350);
            Shape s = layout.getOutline(trans);
            g2.setColor(Color.RED);
            g2.draw(s);
            g2.setColor(Color.BLACK);
            g2.setFont(font);
            g2.drawString(text, 10, 700);
        }
    }
}