LINEAR skin displays values below 0 on spikes

I am currently developing a sound meter app and I noticed that the linear skin shows values below zero although I never set them below zero. I am confident the issue is in the linear skin because using the default skin, the behavior is not reproducible.

This video shows the problem: https://youtu.be/5olzrGAXjC8. Notice that the lower number is the actual value sent to the gauge. Also it looks like if you raise input volume slow enough, the problem does not exist.

I am creating the gauge like this:

gauge = GaugeBuilder.create()
                .skinType(Gauge.SkinType.LINEAR)
                .orientation(Orientation.VERTICAL)
                .title("Input")
                .returnToZero(false)
                .animated(true)
                .animationDuration(25)
                .smoothing(true)
                .needleBehavior(Gauge.NeedleBehavior.OPTIMIZED)
                .prefHeight(gaugePane.getHeight())
                .barColor(Color.CORNFLOWERBLUE)
                .build();

And I update the gauge using a PropertyChangeListener:

gaugeValueProvider.addPropertyChangeListener(gaugeValueName, event -> gauge.setValue((Double) event.getNewValue() * 100));

[HanSolo]

Ok…I’ve made a quick test and you are right…there seems to be something wrong here…will check…

[HanSolo]

Ok the problem is that if the needleBehavior is set to OPTIMIZED the value for the animation will be calculated differently. This is in principle only for a gauge where the needle can rotate 360 degrees. It checks which “way” for the needle is shorter and then use the shorter way for the animation which lead to the negative values if not used in such a gauge. I think I will leave it like it is and make some comment in the code to know next time 😃