JLabel: After overriding paintComponent(). How to make setText() render the text String?

Saleh Feek picture Saleh Feek · Jan 12, 2013 · Viewed 9.1k times · Source

I wrote a subclass of JLabel, and I override paintComponent(Graphics) method to make a gradient background color.

This is the subclass of JLabel:

import java.awt.Color;
import java.awt.Dimension;
import java.awt.GradientPaint;
import java.awt.Graphics;
import java.awt.Graphics2D;
import javax.swing.BorderFactory;
import javax.swing.JLabel;

public class DLabel extends JLabel
{

    Dimension size = new Dimension(70, 80);

    public DLabel()
    {
        this.setPreferredSize(size);
        this.setBorder(BorderFactory.createBevelBorder(TOP, Color.white, Color.black));
    }

    public void paintComponent(Graphics g)
    {
        super.paintComponent(g);
        Graphics2D g2d = (Graphics2D) g;
        Color color1 = new Color(226, 218, 145);
        Color color2 = color1.brighter();
        int w = getWidth();
        int h = getHeight();
        GradientPaint gp = new GradientPaint(
                0, 0, color1, 0, h, color2);
        g2d.setPaint(gp);
        g2d.fillRect(0, 0, w, h);
    }

}

When I create an instance of this label it is displayed correctly, but when I use setText(String) the text is not rendered anything.

DLabel label = new DLabel();
label.setText("I am"); //No text displayed.

I tried different compilations of these methods after setting the text:

label.setOpaque(true);
label.revalidate();
label.repaint();

But nothing happed

Answer

Hovercraft Full Of Eels picture Hovercraft Full Of Eels · Jan 12, 2013

What if you call the super.paintComponent(g) at the end of the method, so that the label draws the text after it draws the gradiant:

public void paintComponent(Graphics g) {
  // super.paintComponent(g);  // *** commented
  Graphics2D g2d = (Graphics2D) g;
  Color color1 = new Color(226, 218, 145);
  Color color2 = color1.brighter();
  int w = getWidth();
  int h = getHeight();
  GradientPaint gp = new GradientPaint(0, 0, color1, 0, h, color2);
  g2d.setPaint(gp);
  g2d.fillRect(0, 0, w, h);
  super.paintComponent(g); // *** added
}

Also, as an unrelated aside, I prefer to change this:

Dimension size = new Dimension(70, 80);

public DLabel()
{
    this.setPreferredSize(size);
    this.setBorder(BorderFactory.createBevelBorder(TOP, Color.white, 
         Color.black));
}

to this:

public static final Dimension PREF_SIZE = new Dimension(70, 80);

public DLabel()
{
    this.setBorder(BorderFactory.createBevelBorder(TOP, Color.white, 
         Color.black));
}

@Override
public Dimension getPreferredSize() {
  Dimension superDim = super.getPreferredSize();
  int width = Math.max(superDim.getWidth(), PREF_SIZE.getWidth());
  int height = Math.max(superDim.getHeight(), PREF_SIZE.getHeight()); 
  return new Dimension(width, height);
}