title: Observable value in validation controlsfx
body: <p>I have the following code</p>
  
  <pre><code>  public ValidationResult notNull(Control control, String content) {
          boolean condition = content.length() &lt;=0;
          return ValidationResult.fromMessageIf(control, "Field is empty!", Severity.WARNING, condition);
      }
  </code></pre>
  
  <p>it checks if there is any character in text field,</p>
  
  <p>the i call it like this </p>
  
  <pre><code>validator = new ValidationSupport();
  
  validator.registerValidator(itemIdTf,vals::notNull);
  </code></pre>
  
  <p>and finally is do this </p>
  
  <pre><code>validator.invalidProperty().addListener((observable, oldValue, newValue) -&gt; {
              itemIdTf.pseudoClassStateChanged(PseudoClass.getPseudoClass("negative"), oldValue);});
  </code></pre>
  
  <p>And this works, it sets the pseudo class for certain controll, how ever when i have few text field controls on same validatior it must wait for all of them to be validated before changing the pseudoclass.</p>
  
  <p>so i thought to perhaps do it in the ValidationResult method, because i think using many validators is probably not good. How ever i dont know if that is possible, i need some listener that is unique to every control, not for validation result.</p>