Java Swing Tips: Html

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)

2013/01/08

make a translucent JButton

Code

class TranslucentButton extends JButton {
  private static final Color TL = new Color(1f, 1f, 1f, .2f);
  private static final Color BR = new Color(0f, 0f, 0f, .4f);
  private static final Color ST = new Color(1f, 1f, 1f, .2f);
  private static final Color SB = new Color(1f, 1f, 1f, .1f);
  private Color ssc;
  private Color bgc;
  private int r = 8;

  public TranslucentButton(String text) {
    super(text);
  }

  public TranslucentButton(String text, Icon icon) {
    super(text, icon);
  }

  @Override public void updateUI() {
    super.updateUI();
    setContentAreaFilled(false);
    setFocusPainted(false);
    setOpaque(false);
    setForeground(Color.WHITE);
  }

  @Override protected void paintComponent(Graphics g) {
    int x = 0;
    int y = 0;
    int w = getWidth();
    int h = getHeight();
    Graphics2D g2 = (Graphics2D) g.create();
    g2.setRenderingHint(
      RenderingHints.KEY_ANTIALIASING,
      RenderingHints.VALUE_ANTIALIAS_ON);
    Shape area = new RoundRectangle2D.Float(x, y, w - 1, h - 1, r, r);
    ssc = TL;
    bgc = BR;
    ButtonModel m = getModel();
    if (m.isPressed()) {
      ssc = SB;
      bgc = ST;
    } else if (m.isRollover()) {
      ssc = ST;
      bgc = SB;
    }
    g2.setPaint(new GradientPaint(x, y, ssc, x, y + h, bgc, true));
    g2.fill(area);
    g2.setPaint(BR);
    g2.draw(area);
    g2.dispose();
    super.paintComponent(g);
  }
}

// ...
private static String makeTitleWithIcon(URL u, String t, String a) {
  return String.format(
    "<html><p align='%s'><img src='%s' align='%s' />&nbsp;%s", a, u, a, t);
}

private static AbstractButton makeButton(String title) {
  return new JButton(title) {
    @Override public void updateUI() {
      super.updateUI();
      setVerticalAlignment(SwingConstants.CENTER);
      setVerticalTextPosition(SwingConstants.CENTER);
      setHorizontalAlignment(SwingConstants.CENTER);
      setHorizontalTextPosition(SwingConstants.CENTER);
      setMargin(new Insets(2, 8, 2, 8));
      setBorder(BorderFactory.createEmptyBorder(2, 8, 2, 8));
      // setBorderPainted(false);
      setContentAreaFilled(false);
      setFocusPainted(false);
      setOpaque(false);
      setForeground(Color.WHITE);
      setIcon(new TranslucentButtonIcon());
    }
  };
}

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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

References

2013/01/08

make a translucent JButton

Code

References