title: Binding Verification Email to disable button property
body: <p>I would like to disable button CREATE ACCOUNT all fields aren't fill correctly.  </p>
  
  <p>I was configured mandatory verification : </p>
  
  <pre><code>    this.buttonRegister.setDisable(true);   
      BooleanBinding disableBinding = this.mailBox.textProperty().isEmpty()
              .or(this.loginField.textProperty().isEmpty()).or(this.passwordField.textProperty().isEmpty())
              .or(this.passwordConfirmField.textProperty().isEmpty())
              .or(this.passwordField.textProperty().isNotEqualTo(this.passwordConfirmField.textProperty()));
  
      this.buttonRegister.disableProperty().bind(disableBinding);
  </code></pre>
  
  <p>I would like also add email verification. I fave a function. But I cannot add this to . my disableBinding.   </p>
  
  <pre><code>private Boolean emalValidation() {
      Pattern p = Pattern.compile("[a-zA-Z0-9][a-zA-Z0-9._]*@[a-zA-Z0-9]+([.][a-zA-Z]+)+");
      Matcher m = p.matcher(this.mailBox.getText());              
      if(m.find() &amp;&amp; m.group().equals(this.mailBox.getText())) {
          return Boolean.TRUE ;
      } else {
          return Boolean.FALSE;
      }
  }
  </code></pre>
  
  <p>How  must I construct a boolean property for this verification ? </p>