Swing/TreeBackgroundSelectionColor のバックアップ(No.1)

class SelectionColorTreeCellRenderer 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);
    if(isSelected) {
      setParticularCondition(value);
      c.setForeground(getTextSelectionColor());
      c.setBackground(getBackgroundSelectionColor());
      if(leaf && value.toString().startsWith("a")) {
        c.setOpaque(true);
        c.setBackground(Color.RED);
      }else{
        c.setOpaque(false);
        c.setBackground(getBackgroundSelectionColor());
      }
    }else{
      c.setForeground(getTextNonSelectionColor());
      c.setBackground(getBackgroundNonSelectionColor());
    }
    return c;
  }
  private Color color = null;
  private void setParticularCondition(Object value) {
    if(value instanceof DefaultMutableTreeNode) {
      Object uo = ((DefaultMutableTreeNode)value).getUserObject();
      if(uo instanceof Color) {
        color = (Color)uo;
        return;
      }
    }
    color = null;
  }
  @Override public Color getBackgroundSelectionColor() {
    return color!=null ? color : super.getBackgroundSelectionColor();
  }
}