void (JFrame frame, boolean fullScreen) { if (X11 == null) return; if (fullScreen) { X11.sendClientMessage(frame, "set FullScreen mode", X11.NET_WM_STATE, NET_WM_STATE_ADD, X11.NET_WM_STATE_FULLSCREEN); } else { X11.sendClientMessage(frame, "reset FullScreen mode", X11.NET_WM_STATE, NET_WM_STATE_REMOVE, X11.NET_WM_STATE_FULLSCREEN); } }