!7 cmodule LockScreen > DynSingleFunction { transient JFrame frame; void doIt { showFullscreen(); } void showFullscreen enter { if (frame != null) activateFrame(frame); frame = showFullScreen(jfullcenter( centerAndSouthWithMargins( jcenteredlabel("Lock mode!"), jbutton("Exit", rThread exitFullscreen)))); onFrameClose(frame, r { frame = null; }); } void exitFullscreen enter { disposeFrame(frame); } }