title: Javafx TextFormatter Backspacing issue
body: <p>I am using <strong>javafx.scene.control.TextFormatter</strong> for format textfield into a currency field. Below shows my code.</p>
  <pre><code>private static final double DEFAULT_VALUE = 0.00d;
  private static final String CURRENCY_SYMBOL = &quot;Rs&quot;; //
  public static final DecimalFormat CURRENCY_DECIMAL_FORMAT
          = new DecimalFormat(CURRENCY_SYMBOL + &quot;###,##0.00&quot;);
  
  public static TextFormatter&lt;Double&gt; currencyFormatter() {
      return new TextFormatter&lt;Double&gt;(new StringConverter&lt;Double&gt;() {
          @Override
          public String toString(Double value) {
              return CURRENCY_DECIMAL_FORMAT.format(value);
          }
  
          @Override
          public Double fromString(String string) {
              try {
                  return CURRENCY_DECIMAL_FORMAT.parse(string).doubleValue();
              } catch (ParseException e) {
                  return Double.NaN;
              }
          }
      }, DEFAULT_VALUE,
              change -&gt; {
                  try {
                      CURRENCY_DECIMAL_FORMAT.parse(change.getControlNewText());
                      return change;
                  } catch (ParseException e) {
                      return null;
                  }
              }
      );
  }
  
  //format textfield into a currency formatted field
  text_field.setTextFormatter(SomeClass.currencyFormatter());
  </code></pre>
  <p>Everything works fine except I cannot backspace out the whole textfield.</p>
  <p><a href="https://i.stack.imgur.com/xyGIL.gif" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/xyGIL.gif" alt="enter image description here" /></a></p>
  <p>Any help would be appreciable. Thank you!</p>