\environment onandon-speed-000

\ProcessSample{bodyfont} \setupbodyfont[dejavu]

\starttext

\def\Sample#1%
  {\start
   \switchtobodyfont[#1]
   \setbox\scratchbox\hbox{\tf\bf\it\bi}%
   \stop}

\ProcessSample{bodyfont switch and 4 style changes (first time)}
\ProcessSample{bodyfont switch and 4 style changes (follow up)}

\stoptext