Dispatchers.JavaFx context and
Dispatchers.Main implementation for JavaFX UI applications.
Creates an instance of a cold Flow that subscribes to the given ObservableValue and emits its values as they change. The resulting flow is conflated, meaning that if several values arrive in quick succession, only the last one will be emitted. Since this implementation uses ObservableValue.addListener, even if this ObservableValue supports lazy evaluation, eager computation will be enforced while the flow is being collected. All the calls to JavaFX API are performed in Dispatchers.JavaFx. This flow emits at least the initial value.