Dynamically Modify the Content Inserted by the Author

Here is some sample code:

    authorAccess.getDocumentController().setDocumentFilter
(new AuthorDocumentFilter() {
    /**
     * @see ro.sync.ecss.extensions.api.AuthorDocumentFilter#insertText
(ro.sync.ecss.extensions.api.AuthorDocumentFilterBypass, int, java.lang.String)
     */
    @Override
    public void insertText(AuthorDocumentFilterBypass filterBypass, 
int offset, String toInsert) {
      if(toInsert.length() == 1 && "\"".equals(toInsert)) {
        //User typed a quote but he actually needs a smart quote.
        //So we either have to add \u201E (start smart quote)
        //Or we add \u201C (end smart quote)
        //Depending on whether there's already a start smart quote inserted
in the current paragraph.
     
      try {
        AuthorNode currentNode = 
authorAccess.getDocumentController().getNodeAtOffset(offset);
        int startofTextInCurrentNode = currentNode.getStartOffset();
        if(offset > startofTextInCurrentNode) {
          Segment seg = new Segment();
        authorAccess.getDocumentController().getChars(startofTextInCurrentNode, 
offset - startofTextInCurrentNode, seg);
          String previosTextInNode = seg.toString();
          boolean insertStartQuote = true;
          for (int i = previosTextInNode.length() - 1; i >= 0; i--) {
            char ch = previosTextInNode.charAt(i);
            if('\u201C' == ch) {
              //Found end of smart quote, so yes, we should insert a start one
              break;
            } else if('\u201E' == ch) {
              //Found start quote, so we should insert an end one.
              insertStartQuote = false;
              break;
            }
          }
         
          if(insertStartQuote) {
            toInsert = "\u201E";
          } else {
            toInsert = "\u201C";
          }
        }
      } catch (BadLocationException e) {
        e.printStackTrace();
      }
    }
    System.err.println("INSERT TEXT |" + toInsert + "|");
    super.insertText(filterBypass, offset, toInsert);
  }
});