Dimension () { Dimension sizeFromHeader = myHeaderPanel.getPreferredSize(); if (sizeFromHeader == null) { sizeFromHeader = myHeaderPanel.getMinimumSize(); } if (sizeFromHeader == null) { int minimumSize = myWindow.getFontMetrics(myHeaderPanel.getFont()).getHeight(); sizeFromHeader = new Dimension(minimumSize, minimumSize); } return sizeFromHeader; }