java - Decorating a JTextField with an image and hint

Question

I'm trying to create some nicer looking JTextFields with an image and a hint. To do this I made a decorator that overrides the paintComponent method. The reason I used a decorator is that I wanted to apply it to other types of JTextField such as JPasswordField.

Here is what I've made so far;

The problem as seen in the form on the left is that, even though I have used a JPasswordField the paintComponent seems to ignore what I assume is the passwords paintComponent which presumably does the password masking symbols.

So the question is, how can I avoid duplicating the code for JTextFields and JPasswordFields but still have the different functionality such as password masking.

This is the decorator code;

public class JTextFieldHint extends JTextField implements FocusListener{
private JTextField jtf;
private Icon icon;
private String hint;
private Insets dummyInsets;

public JTextFieldHint(JTextField jtf, String icon, String hint){
    this.jtf = jtf;
    setIcon(createImageIcon("icons/"+icon+".png",icon));
    this.hint = hint;

    Border border = UIManager.getBorder("TextField.border");
    JTextField dummy = new JTextField();
    this.dummyInsets = border.getBorderInsets(dummy);

    addFocusListener(this);
}

public void setIcon(Icon newIcon){
    this.icon = newIcon;
}

@Override
protected void paintComponent(Graphics g) {
        super.paintComponent(g);

        int textX = 2;

        if(this.icon!=null){
            int iconWidth = icon.getIconWidth();
            int iconHeight = icon.getIconHeight();
            int x = dummyInsets.left + 5;
            textX = x+iconWidth+2;
            int y = (this.getHeight() - iconHeight)/2;
            icon.paintIcon(this, g, x, y);
        }

        setMargin(new Insets(2, textX, 2, 2));

        if ( this.getText().equals("")) {
            int width = this.getWidth();
            int height = this.getHeight();
            Font prev = g.getFont();
            Font italic = prev.deriveFont(Font.ITALIC);
            Color prevColor = g.getColor();
            g.setFont(italic);
            g.setColor(UIManager.getColor("textInactiveText"));
            int h = g.getFontMetrics().getHeight();
            int textBottom = (height - h) / 2 + h - 4;
            int x = this.getInsets().left;
            Graphics2D g2d = (Graphics2D) g;
            RenderingHints hints = g2d.getRenderingHints();
            g2d.setRenderingHint(RenderingHints.KEY_TEXT_ANTIALIASING, RenderingHints.VALUE_TEXT_ANTIALIAS_ON);
            g2d.drawString(hint, x, textBottom);
            g2d.setRenderingHints(hints);
            g.setFont(prev);
            g.setColor(prevColor);
        }

}

protected ImageIcon createImageIcon(String path, String description) {
    java.net.URL imgURL = getClass().getResource(path);
    if (imgURL != null) {
        return new ImageIcon(imgURL, description);
    } else {
        System.err.println("Couldn't find file: " + path);
        return null;
    }
}

@Override
public void focusGained(FocusEvent arg0) {
    this.repaint();
}

@Override
public void focusLost(FocusEvent arg0) {
    this.repaint();
}


}

And this is where I create the fields;

JTextField usernameField = new JTextFieldHint(new JTextField(),"user_green","Username");
JTextField passwordField = new JTextFieldHint(new JPasswordField(),"bullet_key","Password");

Hopefully i've not went completely off in the wrong direction here!

Thanks!

EDIT : Again the more I look at it, it is obvious that calling super.paintComponent(g) is going to call the JTextFields paintcomponent, but I can't see how to solve this without duplicating the code.

Answer 1

Text Prompt works with a JPasswordField.

One difference is that the displayed icon disappears when text is entered. If you want the icon to be permanent then I suggest you create a custom "IconBorder* class to paint an Icon rather then do custom painting in the paintComponent() method.

You approach will not work unless you duplicate the code for both JTextField and JPasswordField.

Edit:

Actually you don't need to create a custom IconBorder. The MatteBorder supports the painting of an Icon in a Border.