title: JavaFX tri-stated CheckBox in TableView
body: <p>I want to bind a tri-state CheckBox inside a TableView with a bean property and i have an approximation but only reflect the changes in the checkbox when the property changes, but i dont know how to reflect the changes in the property when the checkbox changed.
  I looked in google, but i didn't find my answer.</p>
  
  <pre><code>    public enum Attending {FALSE, TRUE, UNKNOWN}
      colEp.setCellFactory(new Callback&lt;TableColumn&lt;VentanaExtended, Attending&gt;, TableCell&lt;VentanaExtended, Attending&gt;&gt;() {
  
          @Override
          public TableCell&lt;VentanaExtended, Attending&gt; call(TableColumn&lt;VentanaExtended, Attending&gt; column) {
              return new TableCell&lt;VentanaExtended, Attending&gt;() {
                  final CheckBox checkBox = new CheckBox() {
                      {
                          setAllowIndeterminate(true);
                      }
  
                  };
  
                  @Override
                  public void updateItem(Attending item, boolean empty) {
                      super.updateItem(item, empty);
                      if (empty) {
                          setGraphic(null);
                      } else {                            
                          switch (item) {
                              case TRUE:
                                  checkBox.setSelected(true);
                                  break;
                              case FALSE:
                                  checkBox.setSelected(false);
                                  break;
                              case UNKNOWN:
                                  checkBox.setIndeterminate(true);
                                  break;
                          }
                          setGraphic(checkBox);
                      }
                  }
              ;
          }
      ;
      }
      });
  </code></pre>