!7

sclass JavaEval extends DynPrintLog {
  S expression;
  transient bool calculating;
  transient O value;
  transient JTextField tfInput;
  transient Throwable error;
  
  JComponent visualize() {
    ret northAndCenterWithMargins(
      centerAndEastWithMarginInbetween(
        tfInput = jtextfield(expression),
        hstackWithSpacing(
          jbutton("Eval", rThread evalIt),
          jbutton("Refresh", rThread refresh))),
      super.visualize());
  }
  
  void refresh {
    veryQuickJava_refresh();
    print("Refreshed translator.");
  }
  
  void evalIt {
    if (calculating) ret;
    calculating = true;
    temp tempAfterwards(r { calculating = false });
    S s = gtt(tfInput);
    print("Evaluating: " + s);
    setField(expression := s);
    try {
      setFields(value := javaEval(s), error := null);
      print();
      print(value);
    } catch e {
      setFields(value := null, error := e);
      printStackTrace2(e);
    }
  }
}