Bug: Not on FX application thread exception is inconsistent

[Brian Hudson]

JavaFX like every other modern UI framework is single threaded.

The updating of your “API objects” can and should remain on a background
thread, however once updated the changes which trigger an update to your UI
(changing a value in a bound property) should occur on the JavaFX thread
via Platform.runLater for example.

Also, take the attitude down a notch or two.

Brian


On Mon, Nov 12, 2018 at 10:02 PM Ty Young <youngty1997 at gmail.com> wrote:

>
> On 11/12/18 5:39 PM, Tom Schindl wrote:
> > Hi,
> >
> > You are supposed to interact with Nodes who are currently shown in the
> > SG only only the JavaFX Application Thread.
>
>
> I never touch the GUI in my other threads, ever. The threads simply
> change the value of a type stored in a property. The ChangeListener that
> is used is created in the GUI JavaFX thread.
>
>
> >
> > JavaFX although is not checking each and every property (change) as this
> > would be too resource intensive but at sensitive cases (eg when
> > interacting with Glass) it does check that you run on the correct thread.
>
>
> The update process for updating my API objects is slow(for reasons
> beyond my control), so even assuming I somehow manage to magically
> update everything in the GUI thread, how the hell do you fix the GUI
> stuttering at that point?
>
>
> Really, having an entire application do all of it's processing on one
> thread in 2018 is really just idiotic and asking for trouble.
>
>
> >
> > Even though your TableView, ... updates seem to work you can run into
> > disasterous states - see eg
> https://bugs.openjdk.java.net/browse/JDK-8198577
> >
> > Tom
>
>
> I'm not sure what the bug is about since the description really doesn't
> give much info however I really haven't noticed anything, even long term
> with it being open for 8+ hours. These objects are update very
> frequently as well.
>
>
> To be clear, this isn't some business application that gets info from a
> database or something.
>
>
> > On 10.11.18 06:58, Ty Young wrote:
> >> Hi,
> >>
> >>
> >> My JavaFX program updates API objects in the background via a non FX
> >> thread that, when changed by another program, are reflected in my JavaFX
> >> GUI's controls by property binding, specifically TableView, Slider,
> >> TextField, and ComboBox. Problem is, while JavaFX is OK with this for
> >> TableView, Slider, and TextField, it throws a Not on FX application
> >> thread exception *only* for the ComboBox.
> >>
> >>
> >> The code for the slider looks like this:
> >>
> >>      private class ValueListener implements ChangeListener<Integer>
> >>      {
> >>          @Override
> >>          public void changed(ObservableValue<? extends Integer>
> >> observable, Integer oldValue, Integer newValue)
> >>          {
> >>              slider.getSlider().setValue(newValue);
> >>              slider.getTextBox().setText(newValue.toString());
> >>          }
> >>      }
> >>
> >>
> >> (the slider variable is misleading, it's actually a VBox that contains a
> >> Slider and a TextField. Need to change it but I digress.)
> >>
> >>
> >> which works fine. However this:
> >>
> >>
> >>      private class ValueListener implements ChangeListener<E>
> >>      {
> >>          @Override
> >>          public void changed(ObservableValue<? extends E> observable, E
> >> oldValue, E newValue)
> >>          {
> >>              combo.setValue(newValue);
> >>          }
> >>      }
> >>
> >>
> >> doesn't for the ComboBox.
> >>
> >>
> >> Is this a bug or is there some legitimate invisible reason as to why the
> >> slider/textfield isn't throwing an error but the combobox one is?
> >>
> >>
> >>
>