Dimension (Component c) { Insets insets = getBorderInsets(c); Dimension minSize = new Dimension(insets.right + insets.left, insets.top + insets.bottom); Dimension separatorSize = getTitledSeparator(c).getPreferredSize(); minSize.width = Math.max(minSize.width, separatorSize.width + outsideInsets.left + outsideInsets.right); return minSize; }