The button has a contentAreaFilled
attribute which determines if the look and feel should paint the content area of the button. When you call super.paintComponent
, the look and feel delegate will paint over what you have done.
You can set this property to false
and it should then work.
For example...
import java.awt.Color;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.GradientPaint;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.GridBagLayout;
import java.awt.RenderingHints;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
public class GradientButtons {
public static void main(String[] args) {
new GradientButtons();
}
public GradientButtons() {
EventQueue.invokeLater(new Runnable() {
@Override
public void run() {
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
}
JFrame frame = new JFrame("Testing");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setLayout(new GridBagLayout());
frame.add(new RoundButton("Click me"));
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
});
}
public class RoundButton extends JButton {
public RoundButton(String text) {
super(text);
setBorderPainted(false);
setContentAreaFilled(false);
setFocusPainted(false);
setOpaque(false);
}
@Override
public Dimension getPreferredSize() {
Dimension size = super.getPreferredSize();
int radius = Math.max(size.width, size.height);
size.width = radius;
size.height = radius;
return size;
}
@Override
protected void paintComponent(Graphics g) {
Graphics2D g2d = (Graphics2D) g;
g2d.setRenderingHint(RenderingHints.KEY_ANTIALIASING,
RenderingHints.VALUE_ANTIALIAS_ON);
GradientPaint gp = new GradientPaint(0, 0,
Color.RED, 0, getHeight(),
Color.YELLOW);
g2d.setPaint(gp);
g2d.fillOval(0, 0, getWidth(), getHeight());
super.paintComponent(g);
}
}
}
You may want to check the ButtonModel
's armed
and/or pressed
state so you can also change the way that the button is painted when clicked, as a suggestion...