Bidirecional binding in Javafx StringProperty is not working in inverse direction - binding

Question

I have a classical JavaBean which will be bond with a JavaFX TextField.
public class Cell {
public static final String CELL_VALUE = "Cell.Value";
private Optional<Integer> value;
private final PropertyChangeSupport pcs = new PropertyChangeSupport(this);
public Optional<Integer> getValue() {
return value;
}
public void setValue(Optional<Integer> value) {
Optional<Integer> old = this.value;
this.value = value;
this.pcs.firePropertyChange(CELL_VALUE, old, value);
}
/**
* The values must be from 1 to 9. 0 or null will be converted to Option.none.
*/
public void setValue(int value) {
this.setValue(Optional.of(value));
}
}
Also I created a StringConverter subclass:
import java.util.Optional;
import javafx.util.StringConverter;
public class CellValueStringConverter extends StringConverter<Optional<Integer>> {
#Override
public String toString(Optional<Integer> value) {
System.out.printf("toString() : %s%n", value);
return value.isPresent()? String.valueOf(value.get()): "";
}
#Override
public Optional<Integer> fromString(String string) {
System.out.printf("fromString() : %s%n", string);
if(string.matches("^[1-9]$")) {
return Optional.of(Integer.valueOf(string));
}
if(string.isEmpty() || string.matches("^( |0)$")) {
return Optional.empty();
}
throw new IllegalArgumentException("Illegal value for a Cell: " + string);
}
}
In the controller class, before the main stage become visible, I made the binding between Cell value and TextField:
ObjectProperty<Optional<Integer>> valueProperty = JavaBeanObjectPropertyBuilder.create().bean(cell)
.name("value").build();
final StringProperty textProperty = textField.textProperty();
// Binding ...
textProperty.bindBidirectional(valueProperty, new CellValueStringConverter());
textField.addEventFilter(MouseEvent.MOUSE_CLICKED, me -> {
if (me.getClickCount() == 2) {
cell.setValue(random.nextInt(8) + 1);
}
});
textProperty.addListener(
(ov, oldValue, newValue) -> System.out.printf("textProperty : %s -> %s%n", oldValue, newValue));
valueProperty.addListener(
(ov, oldValue, newValue) -> System.out.printf("valueProperty: %s -> %s%n", oldValue, newValue));
cell.addPropertyChangeListener(
evt -> System.out.printf("cell : %s -> %s%n", evt.getOldValue(), evt.getNewValue()));
When I start the application, I get the message toString() : Optional.empty. When I type a value (Let's say "4") in an empty TextField, these messages are printed:
fromString() : 4
cell : Optional.empty -> Optional[4]
valueProperty: Optional.empty -> Optional[4]
textProperty : -> 4
If I type "8" in this TextField I got this:
fromString() :
cell : Optional[4] -> Optional.empty
valueProperty: Optional[4] -> Optional.empty
textProperty : 4 ->
fromString() : 8
cell : Optional.empty -> Optional[8]
valueProperty: Optional.empty -> Optional[8]
textProperty : -> 8
Finally, if I type "0", the Cell Will become empty:
fromString() :
cell : Optional[8] -> Optional.empty
valueProperty: Optional[8] -> Optional.empty
textProperty : 8 ->
So far, so good. But I if double click over the TextField, instead replace the text, nothing happens. Suppose that the cell value (and the texfField) is 4. When I double click, I get this message:
cell : Optional[4] -> Optional[8]
However the textField continues showing "4". The message in CellValueStringConverter.toString() is not showed.
Supposedly, when I wrapped the cell value in a ObjectProperty (JavaBeanObjectPropertyBuilder.create().bean(cell).name("value").build()), it should observe all changes in the value property. But is is not occuring. What is missing here?
Thanks,
Rafael Afonso

Answer 1

I think that I found a answer or at least a workaround. I had to add a new PropertyChangeEvent to my Cell object to that when the Cell.value attibute is changed, the valueProperty is directly setted:
cell.addPropertyChangeListener(evt -> {
#SuppressWarnings("unchecked")
final Optional<Integer> newValue = (Optional<Integer>) evt.getNewValue();
valueProperty.set(newValue);
});
At least, the things started to work as expected. When I double ciclk over an empty TextField, I get these messages:
cell : Optional.empty -> Optional[2]
toString() : Optional[2]
textProperty : -> 2
valueProperty: Optional.empty -> Optional[2]
And the textField is filled as expected. However, I thought strange that valueProperty message is the last to be printed althought his setter had been the first thing to be called.
If someone have a better idea, it will be welcome.