So I just discovered that:
ObjectProperty<String> objectPropertyString = new
SimpleObjectProperty<>(null);
StringBinding stringBinding = objectPropertyString.asString();
stringBinding.get() == null --> FALSE
stringBinding.get().equals("null") --> TRUE
I care because this fails to do what I want:
Button okayButton;
ComboBox<String> combo;
//...
BooleanBinding dontHaveValue =
Bindings.isEmpty(combo.valueProperty().asString());
okayButton.disableProperty().bind(dontHaveValue);
The behaviour is understandable and obviously too late to change even if we
wanted to (which we probably don't). But I wonder if StringBinding can be
tweaked so you can enable the pass through of null if you choose to?
If others agree I will open an issue.
Scott