JTextField "Bubble" Text

Question

I was wondering if it was possible to make something similar to the tag entering system on StackOverflow in Swing (probably using a JTextField).

Answer 1

You can redefine your own class that extends the JTextField class and make the style you want.

This link might help and there's another example here.

EDIT:

I created a small example of what you want. This is just a draft and can be improved but you have a start point now.

public class MainPanel extends JPanel{

    public MainPanel() {
        super(new BorderLayout());
        final JPanel p = new JPanel(new GridLayout(5,1,5,5));
        final JTextPane tp = new JTextPane();
        final StyledDocument doc = tp.getStyledDocument();
        final SimpleAttributeSet attr =  new SimpleAttributeSet();
        JTextField textField01 = new JTextField(20) {
            //Unleash Your Creativity with Swing and the Java 2D API!
            //http://java.sun.com/products/jfc/tsc/articles/swing2d/index.html
            @Override protected void paintComponent(Graphics g) {
                if(!isOpaque()) {
                    int w = getWidth();
                    int h = getHeight();
                    Graphics2D g2 = (Graphics2D)g.create();
                    g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
                    g2.setColor(UIManager.getColor("TextField.background"));
                    g2.fillRoundRect(0, 0, w-1, h-1, h, h);
                    g2.setColor(Color.GRAY);
                    g2.drawRoundRect(0, 0, w-1, h-1, h, h);
                    g2.dispose();
                }
                super.paintComponent(g);
            }
        };
        textField01.setOpaque(false);
        textField01.setBackground(new Color(0,0,0,0));
        textField01.setBorder(BorderFactory.createEmptyBorder(4, 8, 4, 8));
        textField01.setText("Test");
        textField01.addKeyListener(new KeyAdapter() {
            public void keyReleased(KeyEvent e) {
            }

            public void keyTyped(KeyEvent e) {
                // TODO: Do something for the keyTyped event
            }

            public void keyPressed(KeyEvent e) {
                // TODO: Do something for the keyPressed event
                if(e.getKeyCode() == KeyEvent.VK_ENTER){
                    JTextField textField = (JTextField) e.getSource();
                    String text = textField.getText();
                    textField.setText("");
                    JLabel label = new JLabel(text);
                    label.setOpaque(true);
                    label.setBackground(Color.lightGray);
                    label.setBorder(BorderFactory.createLineBorder(Color.black,1));
                    tp.setCaretPosition(tp.getDocument().getLength());
                    tp.insertComponent(label);
                    try {
                        doc.insertString(doc.getLength(), " ", attr);  
                    }
                    catch (BadLocationException ex){
                        ex.printStackTrace();
                    }
                }
            }
        });
        p.add(textField01);
        p.add(tp);
        add(p);
        setBorder(BorderFactory.createEmptyBorder(20,20,20,20));
        setPreferredSize(new Dimension(320, 200));
    }

    public static void main(String[] args) {
        EventQueue.invokeLater(new Runnable() {
            @Override public void run() {
                createAndShowGUI();
            }
        });
    }

    public static void createAndShowGUI() {
        try{
            UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
        }catch(Exception e) {
            e.printStackTrace();
        }
        JFrame frame = new JFrame("Tags editor");
        frame.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
        frame.getContentPane().add(new MainPanel());
        frame.pack();
        frame.setLocationRelativeTo(null);
        frame.setVisible(true);
    }
}

class RoundedCornerBorder extends AbstractBorder {
    @Override public void paintBorder(Component c, Graphics g, int x, int y, int width, int height) {
        Graphics2D g2 = (Graphics2D)g.create();
        g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
        int r = height-1;
        RoundRectangle2D round = new RoundRectangle2D.Float(x, y, width-1, height-1, r, r);
        Container parent = c.getParent();
        if(parent!=null) {
            g2.setColor(parent.getBackground());
            Area corner = new Area(new Rectangle2D.Float(x, y, width, height));
            corner.subtract(new Area(round));
            g2.fill(corner);
        }
        g2.setColor(Color.GRAY);
        g2.draw(round);
        g2.dispose();
    }
    @Override public Insets getBorderInsets(Component c) {
        return new Insets(4, 8, 4, 8);
    }
    @Override public Insets getBorderInsets(Component c, Insets insets) {
        insets.left = insets.right = 8;
        insets.top = insets.bottom = 4;
        return insets;
    }
}