private int getVisibleWidth() {
          int w = tree.getVisibleRect().width - 10;
          Insets insets = tree.getInsets();
          w -= insets.left + insets.right;

          JScrollPane scrollPane = ComponentUtil.getScrollPane(tree);
          if (scrollPane != null) {
            JScrollBar sb = scrollPane.getVerticalScrollBar();
            if (sb != null) {
              w -= sb.getWidth();
            }
          }
          return w;
        }
private int getVisibleWidth()