CODEWITHSUNDEEP
javaswing
ShaggyInjun
ShaggyInjun

Reputation: 2963

Customize detault html link color in java swing

Swing allows html in components like JLabel. This document talks about this in detail. It also shows how the color of a specific text could be changed.

I am working with an existing swing application with thousands of such components. I want to change the color of the link where ever it is used. Doing them one at a time would be very tedious. By default if a color is not specified swing seems to render them as blue.

How can I change this default to something else ?

Upvotes: 5

Views: 1215

Answers (1)

MadProgrammer
MadProgrammer

Reputation: 347214

So, after much digging through code I've learnt...

  1. HTML is rendered by the HTMLEditorKit and associated APIs
  2. The default style sheet used by HTMLEditorKit is maintain centrally/globally within the AppContext...

From HTMLEditorKit#getStyleSheet

 AppContext appContext = AppContext.getAppContext();
 StyleSheet defaultStyles = (StyleSheet) appContext.get(DEFAULT_STYLES_KEY);

This is kind of important as it means, you don't spend a lot of time running about trying to look at the label's look and feel code AND you should be able to change the global style sheet in a single place and affect how everything gets rendered...this may be a good and a bad thing...

The next problem is, you can't actually access the StyleSheet within the AppContext as the DEFAULT_STYLES_KEY is a private static final Object...

This means you have to create an instance HTMLEditorKit and use getStyleSheet to get a reference to it...

Link

import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.Graphics;
import java.awt.Graphics2D;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
import javax.swing.text.html.HTMLEditorKit;
import javax.swing.text.html.StyleSheet;
import sun.awt.AppContext;

public class Test {

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

    public Test() {
        EventQueue.invokeLater(new Runnable() {
            @Override
            public void run() {
                try {
                    UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
                } catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
                    ex.printStackTrace();
                }

                HTMLEditorKit kit = new HTMLEditorKit();
                StyleSheet styleSheet = kit.getStyleSheet();
                styleSheet.addRule("a {color:#ff0000;}");

                JLabel label = new JLabel("<html><a href=http://stackoverflow.com/questions/tagged/java>Stackoverflow</a></html>");

                JFrame frame = new JFrame("Testing");
                frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
                frame.add(label);
                frame.pack();
                frame.setLocationRelativeTo(null);
                frame.setVisible(true);
            }
        });
    }

}

Upvotes: 6

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