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)