Java Swing Tips: 2020

2020/12/31

Use thumbnail as default Icon for JRadioButton

Code

class SelectedIcon implements Icon {
  private final Icon icon;
  private final Color color;

  protected SelectedIcon(Icon icon, Color color) {
    this.icon = icon;
    this.color = color;
  }

  @Override public void paintIcon(Component c, Graphics g, int x, int y) {
    Graphics2D g2 = (Graphics2D) g.create();
    g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
    g2.translate(x, y);
    icon.paintIcon(c, g2, 0, 0);
    Path2D triangle = new Path2D.Double();
    triangle.moveTo(getIconWidth(), getIconHeight() / 2d);
    triangle.lineTo(getIconWidth(), getIconHeight());
    triangle.lineTo(getIconWidth() - getIconHeight() / 2d, getIconHeight());
    triangle.closePath();

    g2.setPaint(color);
    g2.fill(triangle);
    g2.setStroke(new BasicStroke(3f));
    g2.drawRect(0, 0, getIconWidth(), getIconHeight());
    g2.setPaint(Color.WHITE);
    Font f = g2.getFont();
    g2.drawString("?", getIconWidth() - f.getSize(), getIconHeight() - 3);
    g2.dispose();
  }

  @Override public int getIconWidth() {
    return icon.getIconWidth();
  }

  @Override public int getIconHeight() {
    return icon.getIconHeight();
  }
}

Explanation

Change the default radio button of JRadioButton to an image thumbnail and the selected state button to an icon with a border drawn on the thumbnail.

References

2020/11/30

Create switchable buttons in JSlider

Use JSlider to create switch buttons that can be toggled on and off by clicking the mouse or dragging the knob

Code

UIDefaults d = new UIDefaults();
d.put("Slider.thumbHeight", 40);
d.put("Slider.thumbWidth", 40);
d.put("Slider:SliderTrack[Enabled].backgroundPainter", (Painter) (g, c, w, h) -> {
  int arc = 40;
  int fillLeft = 2;
  int fillTop = 2;
  int trackWidth = w - fillLeft - fillLeft;
  int trackHeight = h - fillTop - fillTop;
  int baseline = trackHeight - fillTop - fillTop; // c.getBaseline(w, h);
  String off = "Off";

  g.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
  g.setColor(Color.GRAY);
  g.fillRoundRect(fillLeft, fillTop, trackWidth, trackHeight, arc, arc);
  g.setPaint(Color.WHITE);
  g.drawString(off, w - g.getFontMetrics().stringWidth(off) - fillLeft * 5, baseline);

  int fillRight = getXPositionForValue(c, new Rectangle(fillLeft, fillTop, trackWidth, trackHeight));
  g.setColor(Color.ORANGE);
  g.fillRoundRect(fillLeft + 1, fillTop, fillRight - fillLeft, trackHeight, arc, arc);

  g.setPaint(Color.WHITE);
  if (fillRight - fillLeft > 0) {
    g.drawString("On", fillLeft * 5, baseline);
  }
  g.setStroke(new BasicStroke(2.5f));
  g.drawRoundRect(fillLeft, fillTop, trackWidth, trackHeight, arc, arc);
});

Painter thumbPainter = (g, c, w, h) -> {
  int fillLeft = 8;
  int fillTop = 8;
  int trackWidth = w - fillLeft - fillLeft;
  int trackHeight = h - fillTop - fillTop;
  g.setPaint(Color.WHITE);
  g.fillOval(fillLeft, fillTop, trackWidth, trackHeight);
};
d.put("Slider:SliderThumb[Disabled].backgroundPainter", thumbPainter);
d.put("Slider:SliderThumb[Enabled].backgroundPainter", thumbPainter);
d.put("Slider:SliderThumb[Focused+MouseOver].backgroundPainter", thumbPainter);
d.put("Slider:SliderThumb[Focused+Pressed].backgroundPainter", thumbPainter);
d.put("Slider:SliderThumb[Focused].backgroundPainter", thumbPainter);
d.put("Slider:SliderThumb[MouseOver].backgroundPainter", thumbPainter);
d.put("Slider:SliderThumb[Pressed].backgroundPainter", thumbPainter);

JSlider slider = new JSlider(0, 1, 0) {
  @Override public Dimension getPreferredSize() {
    return new Dimension(100, 40);
  }
};
slider.setFont(slider.getFont().deriveFont(Font.BOLD, 32f));
slider.putClientProperty("Nimbus.Overrides", d);

Explanation

Default
- Set JSlider to Min 0, Max 1
- Change component size by overriding getPreferredSize()
Thumb size
- Resize knobs by setting Slider.thumbWidth, Slider.thumbHeight
SliderTrack
- Create a Painter to draw the track background and change the background color, border, and On/Off text
- Pressing a track turns On/Off
- Change the drawing of the knob by setting Painter
- Add MouseMotionListener to redraw the whole thing while dragging, since some afterimages may appear when you drag the knob
- Pressing or clicking the knob does not cause the `On/Off 'toggle
JSlider + JLayer
- The drawing of the track and knob is identical to the above SliderTrack
- Use JLayer to set JSlider to switch On/Off regardless of track or knob
- Redraw while dragging the knob is also done in LayerUI#processMouseMotionEvent(...)

class ToggleSwitchLayerUI extends LayerUI {
  @Override public void installUI(JComponent c) {
    super.installUI(c);
    if (c instanceof JLayer) {
      ((JLayer) c).setLayerEventMask(AWTEvent.MOUSE_EVENT_MASK | AWTEvent.MOUSE_MOTION_EVENT_MASK);
    }
  }

  @Override public void uninstallUI(JComponent c) {
    if (c instanceof JLayer) {
      ((JLayer) c).setLayerEventMask(0);
    }
    super.uninstallUI(c);
  }

  @Override protected void processMouseEvent(MouseEvent e, JLayer l) {
    if (e.getID() == MouseEvent.MOUSE_PRESSED && SwingUtilities.isLeftMouseButton(e)) {
      e.getComponent().dispatchEvent(new MouseEvent(
          e.getComponent(),
          e.getID(), e.getWhen(),
          InputEvent.BUTTON3_DOWN_MASK, // e.getModifiers(),
          e.getX(), e.getY(),
          e.getXOnScreen(), e.getYOnScreen(),
          e.getClickCount(),
          e.isPopupTrigger(),
          MouseEvent.BUTTON3)); // e.getButton());
      e.consume();
    } else if (e.getID() == MouseEvent.MOUSE_CLICKED && SwingUtilities.isLeftMouseButton(e)) {
      JSlider slider = l.getView();
      int v = slider.getValue();
      if (slider.getMinimum() == v) {
        slider.setValue(slider.getMaximum());
      } else if (slider.getMaximum() == v) {
        slider.setValue(slider.getMinimum());
      }
    }
  }

  @Override protected void processMouseMotionEvent(MouseEvent e, JLayer l) {
    l.getView().repaint();
  }
}

References

2020/10/31

Show or hide each TableColumn added to the JTableHeader

Code

class TableHeaderPopupMenu extends JPopupMenu {
  protected TableHeaderPopupMenu(JTable table) {
    super();
    TableColumnModel columnModel = table.getColumnModel();
    List>TableColumn> list = Collections.list(columnModel.getColumns());
    list.forEach(tableColumn -> {
      String name = Objects.toString(tableColumn.getHeaderValue());
      // System.out.format("%s - %s%n", name, tableColumn.getIdentifier());
      JCheckBoxMenuItem item = new JCheckBoxMenuItem(name, true);
      item.addItemListener(e -> {
        if (((AbstractButton) e.getItemSelectable()).isSelected()) {
          columnModel.addColumn(tableColumn);
        } else {
          columnModel.removeColumn(tableColumn);
        }
        updateMenuItems(columnModel);
      });
      add(item);
    });
  }

  @Override public void show(Component c, int x, int y) {
    if (c instanceof JTableHeader) {
      JTableHeader header = (JTableHeader) c;
      JTable table = header.getTable();
      header.setDraggedColumn(null);
      header.repaint();
      table.repaint();
      updateMenuItems(header.getColumnModel());
      super.show(c, x, y);
    }
  }

  private void updateMenuItems(TableColumnModel columnModel) {
    boolean isOnlyOneMenu = columnModel.getColumnCount() == 1;
    if (isOnlyOneMenu) {
      stream(this).map(MenuElement::getComponent).forEach(mi ->
          mi.setEnabled(!(mi instanceof AbstractButton)
                        || !((AbstractButton) mi).isSelected()));
    } else {
      stream(this).forEach(me -> me.getComponent().setEnabled(true));
    }
  }

  private static Stream>MenuElement> stream(MenuElement me) {
    return Stream.of(me.getSubElements())
      .flatMap(m -> Stream.concat(Stream.of(m), stream(m)));
  }
}

Explanation

Initially shows all TableColumns generated from a TableModel

All JCheckBoxMenuItems are also selected

TableColumn hidden with TableColumnModel#removeColumn(TableColumn) method when deselected with JCheckBoxMenuItem

The column is removed from TableColumnModel and hidden from JTableHeader, but the column remains in TableModel
Check the number of TableColumn columns to enable/disable the JCheckBoxMenuItem, e.g. when opening a JPopupMenu, so that all TableColumns are not hidden

Show TableColumn with TableColumnModel#addColumn(TableColumn) method when selected and set with JCheckBoxMenuItem

Columns are added to TableColumnModel and appear in JTableHeader, but TableModel is unchanged from its initial state

UIManager.put("CheckBoxMenuItem.doNotCloseOnMouseClick", true) in Java 9 or higher; If set to and the currently selected TableColumn is hidden with JCheckBoxMenuItem while JPopupMenu is open, an ArrayIndexOutOfBoundsException will occur

Add PopupMenuListener to JPopupMenu or override the JPopupMenu#show(...) method to JTableHeader.setDraggedColumn(null) can be avoided by clearing the selection state in the scene view

References

2020/09/30

Creating StatusBar with size grips to resize the JFrame

Code

class ResizeWindowListener extends MouseInputAdapter {
  private final Rectangle rect = new Rectangle();
  private final Point startPt = new Point();

  @Override public void mousePressed(MouseEvent e) {
    Component p = SwingUtilities.getRoot(e.getComponent());
    if (p instanceof Window) {
      startPt.setLocation(e.getPoint());
      rect.setBounds(p.getBounds());
    }
  }

  @Override public void mouseDragged(MouseEvent e) {
    Component p = SwingUtilities.getRoot(e.getComponent());
    if (!rect.isEmpty() && p instanceof Window) {
      Point pt = e.getPoint();
      rect.width += pt.x - startPt.x;
      rect.height += pt.y - startPt.y;
      p.setBounds(rect);
    }
  }
}

// Size Grip
// Create a GripIcon with a JLabel and position it at the right end(BorderLayout.EAST) of the StatusBar
class BottomRightCornerLabel extends JLabel {
  private transient MouseInputListener handler;

  protected BottomRightCornerLabel() {
    super(new BottomRightCornerIcon());
  }

  @Override public void updateUI() {
    removeMouseListener(handler);
    removeMouseMotionListener(handler);
    super.updateUI();
    handler = new ResizeWindowListener();
    addMouseListener(handler);
    addMouseMotionListener(handler);
    setCursor(Cursor.getPredefinedCursor(Cursor.SE_RESIZE_CURSOR));
  }
}

// Grip Icon
// Draw six rectangles to create a Windows 10 like icon
class BottomRightCornerIcon implements Icon {
  private static final Color SQUARE_COLOR = new Color(160, 160, 160, 160);

  @Override public void paintIcon(Component c, Graphics g, int x, int y) {
    int diff = 3;
    Graphics2D g2 = (Graphics2D) g.create();
    g2.translate(getIconWidth() - diff * 3 - 1, getIconHeight() - diff * 3 - 1);

    int firstRow = 0;
    int secondRow = firstRow + diff;
    int thirdRow = secondRow + diff;

    int firstColumn = 0;
    drawSquare(g2, firstColumn, thirdRow);

    int secondColumn = firstColumn + diff;
    drawSquare(g2, secondColumn, secondRow);
    drawSquare(g2, secondColumn, thirdRow);

    int thirdColumn = secondColumn + diff;
    drawSquare(g2, thirdColumn, firstRow);
    drawSquare(g2, thirdColumn, secondRow);
    drawSquare(g2, thirdColumn, thirdRow);

    g2.dispose();
  }

  @Override public int getIconWidth() {
    return 16;
  }

  @Override public int getIconHeight() {
    return 20;
  }

  private void drawSquare(Graphics g, int x, int y) {
    g.setColor(SQUARE_COLOR);
    g.fillRect(x, y, 2, 2);
  }
}

References

2020/08/31

Overlap the JLabel with a ribbon and slanted string in the corner

Code

class BadgeLabel extends JLabel {
  private final Color ribbonColor = new Color(0xAA_FF_64_00, true);
  private final String ribbonText;

  protected BadgeLabel(Icon image) {
    super(image);
    this.ribbonText = null;
  }

  protected BadgeLabel(Icon image, String ribbonText) {
    super(image);
    this.ribbonText = ribbonText;
  }

  @Override public void updateUI() {
    super.updateUI();
    setBorder(BorderFactory.createEmptyBorder(8, 8, 8, 8));
    setVerticalAlignment(SwingConstants.CENTER);
    setVerticalTextPosition(SwingConstants.BOTTOM);
    setHorizontalAlignment(SwingConstants.CENTER);
    setHorizontalTextPosition(SwingConstants.CENTER);
  }

  @Override protected void paintComponent(Graphics g) {
    Graphics2D g2 = (Graphics2D) g.create();
    g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING,
                        RenderingHints.VALUE_ANTIALIAS_ON);
    g2.setPaint(Color.WHITE);
    g2.fill(getShape());
    super.paintComponent(g);

    if (ribbonText != null) {
      Dimension d = getSize();
      float fontSize = 10f;
      int cx = (d.width - (int) fontSize) / 2;
      double theta = Math.toRadians(45d);

      Font font = g2.getFont().deriveFont(fontSize);
      g2.setFont(font);
      FontRenderContext frc = new FontRenderContext(null, true, true);

      Shape ribbon = new Rectangle2D.Double(cx, -fontSize, d.width, fontSize);
      AffineTransform at = AffineTransform.getRotateInstance(theta, cx, 0);
      g2.setPaint(ribbonColor);
      g2.fill(at.createTransformedShape(ribbon));

      TextLayout tl = new TextLayout(ribbonText, font, frc);
      g2.setPaint(Color.WHITE);
      Rectangle2D r = tl.getOutline(null).getBounds2D();
      double dx = cx + (d.width - cx) / Math.sqrt(2d) - r.getWidth() / 2d;
      double dy = fontSize / 2d + r.getY();
      AffineTransform tx = AffineTransform.getTranslateInstance(dx, dy);
      Shape s = tl.getOutline(tx);
      g2.fill(at.createTransformedShape(s));
    }
    g2.dispose();
  }

  @Override public boolean isOpaque() {
    return false;
  }

  protected Shape getShape() {
    Dimension d = getSize();
    double r = d.width / 2d;
    return new RoundRectangle2D.Double(
        0d, 0d, d.width - 1d, d.height - 1d, r, r);
  }
}

Explanation

JLabel

Override JLabel#isOpaque() to make it transparent
Overrides JLabel#paintComponent(...) to draw a round rectangle for the background, then the original icon for `JLabel`, then the ribbon in the upper right corner, then the ribbon string

Ribbon

Create a Rectangle for the ribbon so that the lower left of the ribbon is positioned near the middle of the x axis of the parent JLabel
Rotate the lower left corner of the ribbon rectangle 45 degrees(Math.toRadians(45d)) about the origin

Ribbon string

Convert the Ribbon string to Shape using the TextLayout.getOutline(...) method
Rotate this Shape 45 degrees from its bottom left

References

Overlap the JLabel with a ribbon and slanted string in the corner(Japanese)

2020/07/31

Show a badge using JLayer for icon in a JLabel

Code

class BadgeLayerUI extends LayerUI {
  private static final int BADGE_SIZE = 17;
  private static final Point OFFSET = new Point(6, 2);
  private final Rectangle viewRect = new Rectangle();
  private final Rectangle iconRect = new Rectangle();
  private final Rectangle textRect = new Rectangle();

  @Override public void paint(Graphics g, JComponent c) {
    super.paint(g, c);
    if (c instanceof JLayer) {
      Graphics2D g2 = (Graphics2D) g.create();
      g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
      iconRect.setBounds(0, 0, 0, 0);
      textRect.setBounds(0, 0, 0, 0);
      BadgeLabel label = (BadgeLabel) ((JLayer<?>) c).getView();
      SwingUtilities.calculateInnerArea(label, viewRect);
      SwingUtilities.layoutCompoundLabel(
          label,
          label.getFontMetrics(label.getFont()),
          label.getText(),
          label.getIcon(),
          label.getVerticalAlignment(),
          label.getHorizontalAlignment(),
          label.getVerticalTextPosition(),
          label.getHorizontalTextPosition(),
          viewRect,
          iconRect,
          textRect,
          label.getIconTextGap()
      );

      int x = iconRect.x + iconRect.width - BADGE_SIZE + OFFSET.x;
      int y = iconRect.y + iconRect.height - BADGE_SIZE + OFFSET.y;
      g2.translate(x, y);
      Icon badge = new BadgeIcon(label.getCounter(), Color.WHITE, new Color(0xAA_32_16_16, true));
      badge.paintIcon(label, g2, 0, 0);
      g2.dispose();
    }
  }
}

class BadgeIcon implements Icon {
  private final Color badgeBgc;
  private final Color badgeFgc;
  private final int value;

  protected BadgeIcon(int value, Color fgc, Color bgc) {
    this.value = value;
    this.badgeFgc = fgc;
    this.badgeBgc = bgc;
  }

  @Override public void paintIcon(Component c, Graphics g, int x, int y) {
    if (value <= 0) {
      return;
    }
    int w = getIconWidth();
    int h = getIconHeight();
    Graphics2D g2 = (Graphics2D) g.create();
    g2.translate(x, y);
    RoundRectangle2D badge = new RoundRectangle2D.Double(0, 0, w, h, 6, 6);
    g2.setPaint(badgeBgc);
    g2.fill(badge);
    g2.setPaint(badgeBgc.darker());
    g2.draw(badge);

    g2.setPaint(badgeFgc);
    FontRenderContext frc = g2.getFontRenderContext();
    // Java 12:
    // NumberFormat fmt = NumberFormat.getCompactNumberInstance(
    //     Locale.US, NumberFormat.Style.SHORT);
    // String txt = fmt.format(value);
    String txt = value > 999 ? "1K" : Objects.toString(value);
    AffineTransform at = txt.length() < 3 ? null : AffineTransform.getScaleInstance(.66, 1d);
    Shape shape = new TextLayout(txt, g2.getFont(), frc).getOutline(at);
    Rectangle2D b = shape.getBounds();
    Point2D p = new Point2D.Double(
        b.getX() + b.getWidth() / 2d, b.getY() + b.getHeight() / 2d);
    AffineTransform toCenterAT = AffineTransform.getTranslateInstance(
        w / 2d - p.getX(), h / 2d - p.getY());
    g2.fill(toCenterAT.createTransformedShape(shape));
    g2.dispose();
  }

  @Override public int getIconWidth() {
    return 17;
  }

  @Override public int getIconHeight() {
    return 17;
  }
}

Explanation

Set JLabel to JLayer to display Badge near the specified corner of the Icon area inside the JLabel body

Icon area inside JLabel can be retrieved with SwingUtilities.layoutCompoundLabel(...) method

Show 6px and Badge offset in x axis and 2px offset in y axis, so need to set more margin in JLabel

If you also want to display text in JLabel, the text may overlap with Badge if IconTextGap is not set considering the above offset

Icons for Badge created with a fixed size of 17x17 using RoundRectangle2D or Ellipse2D

Suppress Badge if value is 0

Set to 1K for all numbers with more than 4 digits

If the number to be displayed is 3 digits, apply a transformation of 66% to set the length.

References

Show a badge using JLayer for icon in a JLabel(Japanese)

2020/06/30

Create a month calendar with diagonally split JTable cells

Code

class CalendarTableRenderer extends DefaultTableCellRenderer {
  private final JPanel p = new JPanel();

  @Override public Component getTableCellRendererComponent(
        JTable table, Object value, boolean selected, boolean focused,
        int row, int column) {
    JLabel c = (JLabel) super.getTableCellRendererComponent(
        table, value, selected, focused, row, column);
    if (value instanceof LocalDate) {
      LocalDate d = (LocalDate) value;
      c.setText(Objects.toString(d.getDayOfMonth()));
      c.setVerticalAlignment(SwingConstants.TOP);
      c.setHorizontalAlignment(SwingConstants.LEFT);
      updateCellWeekColor(d, c, c);

      LocalDate nextWeekDay = d.plusDays(7);
      boolean isLastRow = row == table.getModel().getRowCount() - 1;
      if (isLastRow &&
          YearMonth.from(nextWeekDay).equals(YearMonth.from(getCurrentLocalDate()))) {
        JLabel sub = new JLabel(Objects.toString(nextWeekDay.getDayOfMonth()));
        sub.setBorder(BorderFactory.createEmptyBorder(1, 1, 1, 1));
        sub.setOpaque(false);
        sub.setVerticalAlignment(SwingConstants.BOTTOM);
        sub.setHorizontalAlignment(SwingConstants.RIGHT);

        p.removeAll();
        p.setLayout(new BorderLayout());
        p.add(sub, BorderLayout.SOUTH);
        p.add(c, BorderLayout.NORTH);
        p.setBorder(c.getBorder());
        c.setBorder(BorderFactory.createEmptyBorder(1, 1, 1, 1));

        updateCellWeekColor(d, sub, p);
        return new JLayer>>(p, new DiagonallySplitCellLayerUI());
      }
    }
    return c;
  }
  // ...
}

class DiagonallySplitCellLayerUI extends LayerUI>JPanel> {
  @Override public void paint(Graphics g, JComponent c) {
    super.paint(g, c);
    if (c instanceof JLayer) {
      Graphics2D g2 = (Graphics2D) g.create();
      g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
      g2.setPaint(UIManager.getColor("Table.gridColor"));
      g2.drawLine(c.getWidth(), 0, 0, c.getHeight());
      g2.dispose();
    }
  }
}

Explanation

The sixth week of the month calendar is shown in diagonally split cells for the same day of the previous fifth week.

DefaultTableModel#getRowCount() overrides to always return 5, causing the month calendar to display only 5 weeks
If this month is the seventh day after the target date in the cell renderer displaying the fifth week(row==4), add a JLabel for the target date in the JPanel with BorderLayout set as BorderLayout.NORTH and another JLabel with BorderLayout.SOUTH to display the seventh day after the target date
Create a JLayer to display diagonal lines in this JPanel and use it as a cell renderer

References

Create a month calendar with diagonally split JTable cells(Japanese)

2020/05/31

Make text in a JToolTip selectable and copyable

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)

2020/05/02

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

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)

2020/03/31

Rotate the tab title of JTabbedPane vertically by 90 degrees

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)

2020/02/29

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

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)

2020/01/30

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

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)

Google Tag Manager

2020/12/31

Code

Explanation

References

2020/11/30

Code

Explanation

References

2020/10/31

Code

Explanation

References

2020/09/30

Code

References

2020/08/31

Code

Explanation

JLabel

Ribbon

Ribbon string

References

2020/07/31

Code

Explanation

References

2020/06/30

Code

Explanation

References

2020/05/31

Code

References

2020/05/02

Code

References

2020/03/31

Code

References

2020/02/29

Code

References

2020/01/30

Code

References