NullpointerException: Util#colorToCss / SimpleGaugeSkin

[Steffen]

I am developing a Dashboard containing widgets, and SimpleGauge is one of the available widgets.. On Drag&Drop i receive multiple NullpointerExceptions:

Exception in thread "JavaFX Application Thread" java.lang.NullPointerException
    at eu.hansolo.enzo.common.Util.colorToCss(Util.java:82)
    at eu.hansolo.enzo.gauge.skin.SimpleGaugeSkin.handleControlPropertyChanged(SimpleGaugeSkin.java:231)
    at eu.hansolo.enzo.gauge.skin.SimpleGaugeSkin.lambda$registerListeners$60(SimpleGaugeSkin.java:164)
    at eu.hansolo.enzo.gauge.skin.SimpleGaugeSkin$$Lambda$32/92682911.invalidated(Unknown Source)
    at com.sun.javafx.binding.ExpressionHelper$SingleInvalidation.fireValueChangedEvent(ExpressionHelper.java:135)
    at com.sun.javafx.binding.ExpressionHelper.fireValueChangedEvent(ExpressionHelper.java:80)
    at javafx.beans.property.ObjectPropertyBase.fireValueChangedEvent(ObjectPropertyBase.java:105)
    at javafx.beans.property.ObjectPropertyBase.markInvalid(ObjectPropertyBase.java:112)
    at javafx.beans.property.ObjectPropertyBase.set(ObjectPropertyBase.java:145)
    at javafx.css.StyleableObjectProperty.set(StyleableObjectProperty.java:82)
    at javafx.css.StyleableObjectProperty.applyStyle(StyleableObjectProperty.java:68)
    at javafx.scene.CssStyleHelper.resetToInitialValues(CssStyleHelper.java:442)
    at javafx.scene.CssStyleHelper.createStyleHelper(CssStyleHelper.java:222)
    at javafx.scene.Node.impl_processCSS(Node.java:8877)
    at javafx.scene.Parent.impl_processCSS(Parent.java:1250)
    at javafx.scene.control.Control.impl_processCSS(Control.java:872)
    at javafx.scene.Parent.impl_processCSS(Parent.java:1281)
    at javafx.scene.Parent.impl_processCSS(Parent.java:1281)
    at javafx.scene.Parent.impl_processCSS(Parent.java:1281)
    at javafx.scene.control.Control.impl_processCSS(Control.java:872)
    at javafx.scene.Node.processCSS(Node.java:8732)
    at javafx.scene.Node.processCSS(Node.java:8725)
    at javafx.scene.Node.processCSS(Node.java:8725)
    at javafx.scene.Node.processCSS(Node.java:8725)
    at javafx.scene.Node.processCSS(Node.java:8725)
    at javafx.scene.Scene.doCSSPass(Scene.java:561)
    at javafx.scene.Scene.access$3500(Scene.java:198)
    at javafx.scene.Scene$ScenePulseListener.pulse(Scene.java:2366)
    at com.sun.javafx.tk.Toolkit.firePulse(Toolkit.java:330)
    at com.sun.javafx.tk.quantum.QuantumToolkit.pulse(QuantumToolkit.java:479)
    at com.sun.javafx.tk.quantum.QuantumToolkit.pulse(QuantumToolkit.java:460)
    at com.sun.javafx.tk.quantum.QuantumToolkit$13.run(QuantumToolkit.java:327)
    at com.sun.glass.ui.InvokeLaterDispatcher$Future.run(InvokeLaterDispatcher.java:95)
    at com.sun.glass.ui.win.WinDnDClipboard.push(Native Method)
    at com.sun.glass.ui.win.WinSystemClipboard.pushToSystem(WinSystemClipboard.java:234)
    at com.sun.glass.ui.SystemClipboard.flush(SystemClipboard.java:51)
    at com.sun.glass.ui.ClipboardAssistance.flush(ClipboardAssistance.java:59)
    at com.sun.javafx.tk.quantum.QuantumClipboard.flush(QuantumClipboard.java:274)
    at com.sun.javafx.tk.quantum.QuantumToolkit.startDrag(QuantumToolkit.java:1149)
    at javafx.scene.Scene$DnDGesture.dragDetectedProcessed(Scene.java:2911)
    at javafx.scene.Scene$DnDGesture.process(Scene.java:2972)
    at javafx.scene.Scene$DnDGesture.access$8400(Scene.java:2867)
    at javafx.scene.Scene$MouseHandler.process(Scene.java:3705)
    at javafx.scene.Scene$MouseHandler.access$1800(Scene.java:3414)
    at javafx.scene.Scene.impl_processMouseEvent(Scene.java:1676)
    at javafx.scene.Scene$ScenePeerListener.mouseEvent(Scene.java:2467)
    at com.sun.javafx.tk.quantum.GlassViewEventHandler$MouseEventNotification.run(GlassViewEventHandler.java:314)
    at com.sun.javafx.tk.quantum.GlassViewEventHandler$MouseEventNotification.run(GlassViewEventHandler.java:243)
    at java.security.AccessController.doPrivileged(Native Method)
    at com.sun.javafx.tk.quantum.GlassViewEventHandler.handleMouseEvent(GlassViewEventHandler.java:345)
    at com.sun.glass.ui.View.handleMouseEvent(View.java:526)
    at com.sun.glass.ui.View.notifyMouse(View.java:898)
    at com.sun.glass.ui.win.WinApplication._runLoop(Native Method)
    at com.sun.glass.ui.win.WinApplication.access$300(WinApplication.java:39)
    at com.sun.glass.ui.win.WinApplication$4$1.run(WinApplication.java:112)
    at java.lang.Thread.run(Thread.java:744)

[Steffen]

And the SimpleGauge I use:

mGauge = SimpleGaugeBuilder
                .create()
                .animationDuration(100)
                .sectionFill0(Color.web("#97b329"))
                .sectionFill1(Color.web("#aacc2a"))
                .sectionFill2(Color.web("#d4ea35"))
                .sectionFill3(Color.web("#f2de31"))
                .sectionFill4(Color.web("#fccb2e"))
                .sectionFill5(Color.web("#f3a429"))
                .sectionFill6(Color.web("#f18c23"))
                .sectionFill7(Color.web("#f65821"))
                .sectionFill8(Color.web("#f3351f"))
                .sectionFill9(Color.web("#f61319"))
                .sections(new Section(0, 1 * pSize.getMult()), new Section(1 * pSize.getMult(), 2 * pSize.getMult()),
                        new Section(2 * pSize.getMult(), 3 * pSize.getMult()), new Section(3 * pSize.getMult(), 4 * pSize.getMult()),
                        new Section(4 * pSize.getMult(), 5 * pSize.getMult()), new Section(5 * pSize.getMult(), 6 * pSize.getMult()),
                        new Section(6 * pSize.getMult(), 7 * pSize.getMult()), new Section(7 * pSize.getMult(), 8 * pSize.getMult()),
                        new Section(8 * pSize.getMult(), 9 * pSize.getMult()), new Section(9 * pSize.getMult(), 10 * pSize.getMult()))
                .minValue(0).maxValue(10 * pSize.getMult()).value(0).customFontEnabled(true).customFont(Fonts.elektra(20))
                .build();

I use custom section fill colors instead of css style class because it prevents some caching issues in JavaFX.

[Gerrit Grunwald]

Just on my iPad atm, when exactly does the exception occur?

[Gerrit Grunwald]

oh I think I see the problem, could you try to set sections in the SimpleGaugeBuilder before you set the SectionColors? Guess I have to adjust the setter calling in the builder. Other solution might be to set the section colors after you called the SimpleGaugeBuilder.

[Steffen]

I am not at home, too ;-) But I will try that later on, thanks for the suggestion!

[Steffen]

Yes, reordering the Builder statements fixes the issue! Do you want to resolve the issue now or do you want to adjust the Builder first?

[Gerrit Grunwald]

Okidoki, I won't find the time to fix it today but I will try to fix it tomorrow. Thanx for testing and merry christmas :)

[Steffen]

Thanks, do not rush anything and I wish you a merry christmas, too!

[Gerrit Grunwald]

Problem was related to method order in SimpleGaugeBuilder