abstract sclass DynTextArea extends DynModule {
  S text;
  bool noGrab; // noGrab = don't save what user types 
  transient bool enableUndo = true;
  transient JTextArea textArea;
  transient double grabInterval = 10.0; // how often text is grabbed from text area
  
  visualize {
    textArea = typeWriterTextArea(text);
    if (enableUndo) jEnableUndoRedo(textArea);
    ret awtEvery(textArea, grabInterval, r swingToData);
  }
  
  void swingToData {
    if (textArea != null && !noGrab)
      setText(main.getText(textArea));
  }
  
  void unvisualize {
    swingToData();
    super.unvisualize();
  }
  
  // API
  
  void setText(S text) enter {
    if (eq(this.text, text)) ret;
    setField(+text);
    setTextKeepCaret(textArea, text);
  }
  
  void setText_big(S text) enter {
    if (eq(this.text, text)) ret;
    temp tempSetOpt(module(), noGrab := true);
    setField(+text);
    long time = sysNow();
    Document doc = defaultStyledDocumentFromString(text);
    done2_always(time, "Make StyledDocument for " + nChars(text));
    time = sysNow();
    setDocument(textArea, doc);
    done2_always(time, "Apply StyledDocument");
  }
  
  S getText() { swingToData(); ret text; }
  
  void clearText() { setText(""); }
  
  void printToText(O o) {
    setText(getText() + str(o) + "\n");
    moveCaretToEnd(textArea);
  }
}