How to create Button which size is calculated from its text ?

Question

I think JButton works like this: either in constructor or by setText() method the text is set and according the lenght, font and fontRendererContext preffered size is calculated before the layout manager ask for the prefferedSize for first time.
I want to override paint() method because i want to draw my own text(and the only way i discovered how to force button not to paint text is to set text to
null or empty String). I want the button to be as long as length of text plus insets.
But layout manager ask for preffered size before paint method is invoked but i find out what size should be in paint method because i need graphics
parameter to get FontRendererContext from it. So layout manager shrink button to minimum because first time the preffered size calculated from null or
empty String is returned.
public class MyButton extends JButton {
        public MyButton() {
            this.setText(null);  //or setText("");
            this.setContentAreaFilled(false);
            this.setFocusPainted(false);
            this.setBorderPainted(false);
                                                      ////already here i need to know what the size should be
        @Override
        public void paint(Graphics g) {
            Graphics2D g2 = (Graphics2D) g;
            TextLayout textLayout = new TextLayout("MyButton", this.getFont(), g2.getFontRenderContext());
            Rectangle2D boundsOfText = textLayout.getBounds();                                                                    /////////here i find out what size should be
            this.prefferedSize = new Dimension((int)boundsOfText.getWidth()+10,(int) boundsOfText.getHeight()+10);
            g2.setColor(Color.WHITE);
            g2.fillRoundRect(1, 1,(int)getPreferredSize().getWidth(),(int) getPreferredSize().getHeight(), 10, 10);
            g2.setColor(Color.BLACK);
            g2.drawRoundRect(1, 1,(int)getPreferredSize().getWidth(),(int)getPreferredSize().getHeight(), 10, 10);
            g2.drawString("MyButton", 7, (int)boundsOfText.getHeight() + 6);
            g2.dispose();
    }So how can i do that? How can JButton know prefferedSize before its paint method is invoked?

Answer 1

The previous example was simplified.
public class MyButton0 extends JButton {
    private String myText;
    public MyButton0(String text) {
        this.myText = "Button";
        //this.myText = text.toUpperCase();
        this.setFont(new Font("SansSerif", Font.PLAIN, 13));
        setContentAreaFilled(false);
        setBorderPainted(false);
        setFocusPainted(false);
    @Override
    public void paint(Graphics g) {
        Graphics2D g2 = (Graphics2D) g;
        g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
        //backround painting
        GradientPaint background = new GradientPaint(0, 0, new Color(255, 255, 255), 0, getPreferredSize().height / 2, new Color(0, 0, 0), true);
        if(getModel().isRollover()){
            background = new GradientPaint(0, 0, new Color(255, 255, 255), getPreferredSize().width , getPreferredSize().height , new Color(0, 0, 0), true);
        if(getModel().isPressed()){
            background = new GradientPaint(0, 0, new Color(255, 255, 255), 0, getPreferredSize().height / 2, new Color(210, 210, 210), true);
        g2.setPaint(background);
        g2.fillRoundRect(1, 1, getPreferredSize().width - 3 , getPreferredSize().height - 3, 10, 10);
        //Border painting
        g2.setColor(new Color(255, 255, 255));
        g2.setStroke(new BasicStroke(2.0f, BasicStroke.CAP_BUTT, BasicStroke.CAP_BUTT, 10.0f));
        g2.draw(new RoundRectangle2D.Double(1, 1, getPreferredSize().width - 3, getPreferredSize().height - 3, 10, 10));
        //text paiting
        g2.setFont(getFont());
        TextLayout tl = new TextLayout(this.myText, getFont(), g2.getFontRenderContext());
        int startPositionOfText = getPreferredSize().width - (int) tl.getBounds().getWidth();
        startPositionOfText = startPositionOfText / 2;
        g2.setColor(new Color(255, 255, 255));
        g2.drawString(this.myText, startPositionOfText -2, getHeight() / 2 + 5);
        g2.dispose();
    @Override
    public Dimension getPreferredSize() {
        return new Dimension(133, 31);
}Assume text is so long as doesn't fit inside button. I have hard-set preffered size but i would like to calculate preffered size from text lenght.
Or i need calculate startPosition of text to center it. But i don't want have preffered size hard-set.