Make a transparent JTree and translucent selection background

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

Code

class TransparentTreeCellRenderer extends DefaultTreeCellRenderer {
  @Override public Component getTreeCellRendererComponent(
          JTree tree, Object value, boolean isSelected, boolean expanded,
          boolean leaf, int row, boolean hasFocus) {
    JComponent c = (JComponent) super.getTreeCellRendererComponent(
          tree, value, isSelected, expanded, leaf, row, hasFocus);
    c.setOpaque(false);
    return c;
  }
  private final Color ALPHA_OF_ZERO = new Color(0, true);
  @Override public Color getBackgroundNonSelectionColor() {
    return ALPHA_OF_ZERO;
  }
  @Override public Color getBackgroundSelectionColor() {
    return ALPHA_OF_ZERO;
  }
}

class TranslucentTreeCellRenderer extends TransparentTreeCellRenderer {
  private final Color backgroundSelectionColor = new Color(100, 100, 255, 100);

  @Override public Color getBackgroundSelectionColor() {
    return backgroundSelectionColor;
  }
}

References

• Make a transparent JTree and translucent selection background(Japanese)

Translucent JInternalFrame (Nimbus)

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

Code

JPanel p1 = new JPanel();
p1.setOpaque(false);

JPanel p2 = new JPanel() {
  @Override protected void paintComponent(Graphics g) {
    // super.paintComponent(g);
    g.setColor(new Color(100, 50, 50, 100));
    g.fillRect(0, 0, getWidth(), getHeight());
  }
};

JPanel p3 = new JPanel() {
  @Override protected void paintComponent(Graphics g) {
    Graphics2D g2 = (Graphics2D) g;
    // g2.setPaint(new Color(100, 120, 100, 100));
    g2.setPaint(texture);
    g2.fillRect(0, 0, getWidth(), getHeight());
  }
};

protected JInternalFrame createFrame(JPanel panel) {
  MyInternalFrame frame = new MyInternalFrame();
  if (panel != null) {
    frame.setContentPane(panel);
    // JButton button = new JButton("button");
    // button.setOpaque(false);
    panel.add(new JLabel("label"));
    panel.add(new JButton("button"));
  }
  desktop.add(frame);
  frame.setOpaque(false);
  frame.setVisible(true);
  // ...

References

• TranslucentFrame(Japanese)
• TransparentFrame(Japanese)