JLabel text shadow

Question

I have a JLabel with text. The text displays in different colors and since I also want the background to change color, I found sometimes the text it's hard to read. That is why I want to add a shadow to the font like this: React Native font outline / textShadow

Can someone tell me how to get this effect in a Java Swing label or, if not possible, which Swing component I should use instead?

Answer 1

You can convert the text to an outline and stroke it.

import javax.swing.*;
import java.awt.*;
import java.awt.font.FontRenderContext;
import java.awt.font.TextLayout;
import java.awt.image.BufferedImage;

class Test extends JFrame {
    public Test() throws HeadlessException {
        setSize(500, 500);
        add(new JOutlineLabel("test"));
    }
    
    class JOutlineLabel extends JComponent {
        
        int width = 3;
        Shape outline;
        
        public JOutlineLabel(String string) {
            BufferedImage temp = new BufferedImage(200, 200, BufferedImage.TYPE_4BYTE_ABGR);
            Graphics2D g2 = temp.createGraphics();
            
            FontRenderContext frc = g2.getFontRenderContext();
            Font font = new Font("Helvetica", 1, 60);
            
            TextLayout textLayout = new TextLayout(string, font, frc);
            outline = textLayout.getOutline(null);
        }
        
        @Override
        protected void paintComponent(Graphics g) {
            super.paintComponent(g);
            Graphics2D g2 = (Graphics2D) g;
            g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
            g2.setRenderingHint(RenderingHints.KEY_RENDERING, RenderingHints.VALUE_RENDER_QUALITY);
            g2.translate(0, outline.getBounds().height);
            g2.setColor(Color.blue);
            g2.setStroke(new BasicStroke(width));
            g2.draw(outline);
        }
    }
    
    public static void main(String[] args) {
        new Test().setVisible(true);
    }
}

You'll want to avoid the executing heavyweight bits like instantiating the Font, converting the text to an outline, etc every draw.