Make text in a JToolTip selectable and copyable

• download example.jar
• download src.zip
• repository

Code

JEditorPane hint = new JEditorPane();
hint.setEditorKit(new HTMLEditorKit());
hint.setEditable(false);
hint.setOpaque(false);

JCheckBox check = new JCheckBox();
check.setOpaque(false);

JPanel panel = new JPanel(new BorderLayout());
panel.add(hint);
panel.add(check, BorderLayout.EAST);

JPopupMenu popup = new JPopupMenu();
popup.add(new JScrollPane(panel));
popup.setBorder(BorderFactory.createEmptyBorder());

JEditorPane editor = new JEditorPane() {
  @Override public JToolTip createToolTip() {
    JToolTip tip = super.createToolTip();
    tip.addHierarchyListener(e -> {
      if ((e.getChangeFlags() & HierarchyEvent.SHOWING_CHANGED) != 0
            && e.getComponent().isShowing()) {
        panel.setBackground(tip.getBackground());
        popup.show(tip, 0, 0);
      }
    });
    return tip;
  }
};
editor.setEditorKit(new HTMLEditorKit());
editor.setText(HTML_TEXT);
editor.setEditable(false);
editor.addHyperlinkListener(e -> {
  JEditorPane editorPane = (JEditorPane) e.getSource();
  if (e.getEventType() == HyperlinkEvent.EventType.ACTIVATED) {
    JOptionPane.showMessageDialog(editorPane, "You click the link with the URL " + e.getURL());
  } else if (e.getEventType() == HyperlinkEvent.EventType.ENTERED) {
    editorPane.setToolTipText("");
    Optional.ofNullable(e.getSourceElement())
        .map(elem -> (AttributeSet) elem.getAttributes().getAttribute(HTML.Tag.A))
        .ifPresent(attr -> {
          String title = Objects.toString(attr.getAttribute(HTML.Attribute.TITLE));
          String url = Objects.toString(e.getURL());
          // String url = Objects.toString(attr.getAttribute(HTML.Attribute.HREF));
          hint.setText(String.format("%s: %s", title, url, url));
          popup.pack();
        });
  } else if (e.getEventType() == HyperlinkEvent.EventType.EXITED) {
    editorPane.setToolTipText(null);
  }
});

• Override JComponent#createToolTip() method to add HierarchyListener to JToolTip
• Show JPopupMenu with JToolTip as parent when JToolTip is visible
• JToolTip hides behind JPopupMenu
• JPopupMenu adds a JPanel with a JEditorPane and a JCheckBox instead of a JMenuItem
• Hiding the parent JToolTip with the mouse cursor does not close the JPopupMenu, so you can click the internal JCheckBox or select the text in the JEditorPane and copy it with Ctrl-C, etc
• It is a normal JPopupMenu, so it is hidden when the focus is moved by clicking on the parent JFrame etc

References

• Make text in a JToolTip selectable and copyable(Japanese)

Disable the JOptionPane OK button until text is entered in the JTextField

• download example.jar
• download src.zip
• repository

Code

JPanel panel2 = new JPanel(new GridLayout(2, 1));
JTextField field2 = new JTextField();
Border enabledBorder = field2.getBorder();
Insets i = enabledBorder.getBorderInsets(field2);
Border disabledBorder = BorderFactory.createCompoundBorder(
    BorderFactory.createLineBorder(Color.RED),
    BorderFactory.createEmptyBorder(i.top - 1, i.left - 1, i.bottom - 1, i.right - 1));
String disabledMessage = "Text is required to create ...";
JLabel label2 = new JLabel(" ");
label2.setForeground(Color.RED);
panel2.add(field2);
panel2.add(label2);
if (field2.getText().isEmpty()) {
  field2.setBorder(disabledBorder);
  label2.setText(disabledMessage);
}
field2.addHierarchyListener(e -> {
  Component c = e.getComponent();
  if ((e.getChangeFlags() & HierarchyEvent.SHOWING_CHANGED) != 0 && c.isShowing()) {
    EventQueue.invokeLater(c::requestFocusInWindow);
  }
});
field2.getDocument().addDocumentListener(new DocumentListener() {
  private void update() {
    boolean verified = !field2.getText().isEmpty();
    JButton b = field2.getRootPane().getDefaultButton();
    if (verified) {
      b.setEnabled(true);
      field2.setBorder(enabledBorder);
      label2.setText(" ");
    } else {
      b.setEnabled(false);
      field2.setBorder(disabledBorder);
      label2.setText(disabledMessage);
    }
  }

  @Override public void insertUpdate(DocumentEvent e) {
    update();
  }

  @Override public void removeUpdate(DocumentEvent e) {
    update();
  }

  @Override public void changedUpdate(DocumentEvent e) {
    update();
  }
});
JButton button2 = new JButton("show");
button2.addActionListener(e -> {
  Component p2 = log.getRootPane();
  EventQueue.invokeLater(() -> {
    JButton b = field2.getRootPane().getDefaultButton();
    if (b != null && field2.getText().isEmpty()) {
      b.setEnabled(false);
    }
  });
  int ret = JOptionPane.showConfirmDialog(
      p2, panel2, "Input text", JOptionPane.OK_CANCEL_OPTION, JOptionPane.PLAIN_MESSAGE);
  if (ret == JOptionPane.OK_OPTION) {
    log.setText(field2.getText());
  }
});

References

• Disable the JOptionPane OK button until text is entered in the JTextField(Japanese)

Rotate the tab title of JTabbedPane vertically by 90 degrees

• download example.jar
• download src.zip
• repository

Code

private Icon makeVerticalTabIcon(String title, Icon icon, boolean clockwise) {
  JLabel label = new JLabel(title, icon, SwingConstants.LEADING);
  label.setBorder(BorderFactory.createEmptyBorder(0, 2, 0, 2));
  Dimension d = label.getPreferredSize();
  int w = d.height;
  int h = d.width;
  BufferedImage bi = new BufferedImage(w, h, BufferedImage.TYPE_INT_ARGB);
  Graphics2D g2 = (Graphics2D) bi.getGraphics();
  AffineTransform at = clockwise
      ? AffineTransform.getTranslateInstance(w, 0)
      : AffineTransform.getTranslateInstance(0, h);
  at.quadrantRotate(clockwise ? 1 : -1);
  g2.setTransform(at);
  SwingUtilities.paintComponent(g2, label, this, 0, 0, d.width, d.height);
  g2.dispose();
  return new ImageIcon(bi);
}

References

• Rotate the tab title of JTabbedPane vertically by 90 degrees(Japanese)

Display the Unicode code point of the character at the Caret position in the JTextArea

• download example.jar
• download src.zip
• repository

Code

String u1F60x = "😀😁😂😃😄😅😆😇😈😉😊😋😌😍😎😏";
String u1F61x = "😐😑😒😓😔😕😖😗😘😙😚😛😜😝😞😟";
String u1F62x = "😠😡😢😣😤😥😦😧😨😩😪😫😬😭😮😯";
String u1F63x = "😰😱😲😳😴😵😶😷😸😹😺😻😼😽😾😿";
String u1F64x = "🙀🙁🙂　　🙅🙆🙇🙈🙉🙊🙋🙌🙍🙎🙏";

JTextField label = new JTextField();
label.setEditable(false);
label.setFont(label.getFont().deriveFont(32f));

List<String> l = Arrays.asList(u1F60x, u1F61x, u1F62x, u1F63x, u1F64x);
JTextArea textArea = new JTextArea(String.join("\n", l));
textArea.addCaretListener(e -> {
  try {
    int dot = e.getDot();
    int mark = e.getMark();
    if (dot - mark == 0) {
      Document doc = textArea.getDocument();
      String txt = doc.getText(dot, 1);
      int code = txt.codePointAt(0);
      if (Character.isHighSurrogate((char) code)) {
        txt = doc.getText(dot, 2);
        code = txt.codePointAt(0);
      }
      label.setText(String.format("%s: U+%04X", txt, code));
    } else {
      label.setText("");
    }
  } catch (BadLocationException ex) {
    ex.printStackTrace();
  }
});

References

• Display the Unicode code point of the character at the Caret position in the JTextArea(Japanese)

Automatically update JTree node selection based on scroll position to indicate which link is currently active in the viewport of JEditorPane

• download example.jar
• download src.zip
• repository

Code

JScrollPane scroll = new JScrollPane(editor);
scroll.getVerticalScrollBar().getModel().addChangeListener(e -> {
  HTMLDocument.Iterator itr = doc.getIterator(HTML.Tag.A);
  for (; itr.isValid(); itr.next()) {
    try {
      Rectangle r = editor.modelToView(itr.getStartOffset());
      if (r != null && editor.getVisibleRect().contains(r.getLocation())) {
        searchTreeNode(tree, itr.getAttributes().getAttribute(HTML.Attribute.NAME));
        break;
      }
    } catch (BadLocationException ex) {
      UIManager.getLookAndFeel().provideErrorFeedback(editor);
    }
  }
});
// ...
tree.addTreeSelectionListener(e -> {
  if (!tree.isEnabled()) { // Ignore node selection from JEditorPane side
    return;
  }
  Object o = e.getNewLeadSelectionPath().getLastPathComponent();
  if (o instanceof DefaultMutableTreeNode) {
    DefaultMutableTreeNode node = (DefaultMutableTreeNode) o;
    String ref = Objects.toString(node.getUserObject());
    editor.scrollToReference(ref);
  }
});
// ...
private static void searchTreeNode(JTree tree, Object name) {
  TreeModel model = tree.getModel();
  DefaultMutableTreeNode root = (DefaultMutableTreeNode) model.getRoot();
  Collections.list((Enumeration<?>) root.preorderEnumeration()).stream()
      .filter(DefaultMutableTreeNode.class::isInstance)
      .map(DefaultMutableTreeNode.class::cast)
      .filter(node -> Objects.equals(name, Objects.toString(node.getUserObject())))
      .findFirst()
      .ifPresent(node -> {
        tree.setEnabled(false); // Disable TreeSelectionListener in JTree
        TreePath path = new TreePath(node.getPath());
        tree.setSelectionPath(path);
        tree.scrollPathToVisible(path);
        tree.setEnabled(true); // Restores TreeSelectionListener in JTree
      });
}

References

• Automatically update JTree node selection based on scroll position to indicate which link is currently active in the viewport of JEditorPane(Japanese)