Posted by gouessej on Aug 11, 2012; 6:18pm
URL: https://forum.jogamp.org/Setting-proper-window-size-with-NEWT-tp4025780p4025786.html

Please use that to get the height of the task bar until we have a NEWT equivalent:
final int taskBarHeight=SystemTray.getSystemTray().getTrayIconSize().getHeight();