code: @Override
      public void changeVariables(Object source, Map<String, Object> variables) {
          if (variables.containsKey("filter")) {
              final String text = variables.get("filter").toString();
              fireEvent(new TextChangeEvent(this) {
                  @Override
                  public String getText() {
                      return text;
                  }
                  @Override
                  public int getCursorPosition() {
                      return text.length();
                  }
              });
          }
          super.changeVariables(source, variables);
      }
docs: /*
  Source Code found on: http://dev.vaadin.com/ticket/7436
  (On 2013-03-07)