Swing HTML drawString
I'm trying to create some special component for a specific purpose, on that component I need to draw a HTML string, here's a sample code:
public class MyComponent extends JComponent{
public MyComponent(){
super();
}
protected void paintComponent(Graphics g){
//some drawing operations...
g.drawString("<html><u>text to render</u></html>",10,10);
}
}
Unfortunately the drawString method seems to be not recognizing the HTML format, it foolishly draws the string just as it is.
Is there any way to make that work?
Answer
If a fan of Java2D; but to get the most leverage from HTML in Swing components and layouts, I'd encourage you to use the component approach suggested by @camickr. If necessary, you can use the flyweight renderer approach seen in JTable, et al, in which a single component is used repeatedly for drawing. The example below is a very simplified outline of the technique, changing only the color and location.
Addendum: Updated example; see also CellRendererPane and Make your apps fly: Implement Flyweight to improve performance.
import java.awt.Color;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.Graphics;
import javax.swing.CellRendererPane;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
/** @see http://stackoverflow.com/questions/7774960 */
public class PaintComponentTest extends JPanel {
private static final int N = 8;
private static final String s = "<html><big><u>Hello</u></html>";
private JLabel renderer = new JLabel(s);
private CellRendererPane crp = new CellRendererPane();
private Dimension dim;
public PaintComponentTest() {
this.setBackground(Color.black);
dim = renderer.getPreferredSize();
this.add(crp);
}
@Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
for (int i = 0; i < N; i++) {
renderer.setForeground(Color.getHSBColor((float) i / N, 1, 1));
crp.paintComponent(g, renderer, this,
i * dim.width, i * dim.height, dim.width, dim.height);
}
}
private void display() {
JFrame f = new JFrame("PaintComponentTest");
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
f.add(this);
f.pack();
f.setSize(dim.width * N, dim.height * (N + 1));
f.setLocationRelativeTo(null);
f.setVisible(true);
}
public static void main(String[] args) {
EventQueue.invokeLater(new Runnable() {
@Override
public void run() {
new PaintComponentTest().display();
}
});
}
}