Java: JButton with custom Shape: Fill with Metal Look and Feel Gradient

I have a new class derived from JButton which gives me the shape of a Enter-Button.

Now I want to have it filled with the same gradient as the default JButton. But I do not know. How I can do this?

At the moment it is filled with plain black color.

import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Point;
import java.awt.Polygon;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;

public class EnterButton extends JButton {

    private Polygon shape;

    public EnterButton() {
        this.shape = new Polygon();
        // initialisiere Form
        this.initialize();
    }

    protected void initialize() {
        Point p1, p2, p3, p4, p5, p6;

        this.setSize(90, 120);

        p1 = new Point(0, 0);
        p2 = new Point(0, 60);
        p3 = new Point(30, 60);
        p4 = new Point(30, 120);
        p5 = new Point(90, 120);
        p6 = new Point(90, 0);

        this.shape.addPoint((int) Math.round(p1.getX()),
                (int) Math.round(p1.getY()));
        this.shape.addPoint((int) Math.round(p2.getX()),
                (int) Math.round(p2.getY()));
        this.shape.addPoint((int) Math.round(p3.getX()),
                (int) Math.round(p3.getY()));
        this.shape.addPoint((int) Math.round(p4.getX()),
                (int) Math.round(p4.getY()));
        this.shape.addPoint((int) Math.round(p5.getX()),
                (int) Math.round(p5.getY()));
        this.shape.addPoint((int) Math.round(p6.getX()),
                (int) Math.round(p6.getY()));
        this.setMinimumSize(this.getSize());
        this.setMaximumSize(this.getSize());
        this.setPreferredSize(this.getSize());
    }

    // Hit detection
开发者_StackOverflow    public boolean contains(int x, int y) {
        return this.shape.contains(x, y);
    }

    // Zeichne den Button
    protected void paintComponent(Graphics g) {
        Graphics2D gCopy = (Graphics2D) g.create();
        gCopy.fillPolygon(this.shape);

    }

    // zeichne die Border
    protected void paintBorder(Graphics g) {

    }

    public static void main(String[] args) {

        JFrame frame = new JFrame();
        JPanel panel = new JPanel();
        EnterButton button = new EnterButton();

        panel.add(button);
        frame.add(panel);

        frame.pack();
        frame.setVisible(true);

    }

}

Thank you!

See java.awt.GradientPaint.

Also search for the source code of the update(Graphics, JComponent) method of class javax.swing.plaf.metal.MetalButtonUI. That's somewhere under your JDK.

look here or here

but why bother with something that is lots of times made in Custom Look & Feels, some of them allows you change the Color as you wants