Layout regression

[Scott Palmer]

I'm investigating an issue with my application where things are
working fine running with JavaFX 2.2 on 7u55, but I have a particular
case where 8u5 is throwing the following exception during layout:

Exception in thread "JavaFX Application Thread" java.lang.NullPointerException
at javafx.scene.layout.GridPane.computeMinHeights(GridPane.java:1450)
at javafx.scene.layout.GridPane.computeMinHeight(GridPane.java:1224)
at javafx.scene.Parent.minHeight(Parent.java:946)
at javafx.scene.layout.Region.minHeight(Region.java:1404)
at javafx.scene.layout.Region.computeChildMinAreaHeight(Region.java:1700)
at javafx.scene.layout.Region.getMaxAreaHeight(Region.java:1981)
at javafx.scene.layout.Region.computeMaxMinAreaHeight(Region.java:1854)
at javafx.scene.layout.StackPane.computeMinHeight(StackPane.java:293)
at javafx.scene.Parent.minHeight(Parent.java:946)
at javafx.scene.layout.Region.minHeight(Region.java:1404)
at javafx.scene.layout.Region.computeChildPrefAreaHeight(Region.java:1765)
at javafx.scene.layout.Region.getMaxAreaHeight(Region.java:1982)
at javafx.scene.layout.Region.computeMaxPrefAreaHeight(Region.java:1884)
at javafx.scene.layout.StackPane.computePrefHeight(StackPane.java:310)
at javafx.scene.Parent.prefHeight(Parent.java:918)
at javafx.scene.layout.Region.prefHeight(Region.java:1438)
at com.sun.javafx.scene.control.skin.TitledPaneSkin.computePrefHeight(TitledPaneSkin.java:249)
at javafx.scene.control.Control.computePrefHeight(Control.java:543)
at javafx.scene.Parent.prefHeight(Parent.java:918)
at javafx.scene.layout.Region.prefHeight(Region.java:1438)
at javafx.scene.layout.Region.computeChildPrefAreaHeight(Region.java:1765)
at javafx.scene.layout.GridPane.computePrefHeights(GridPane.java:1407)
at javafx.scene.layout.GridPane.computePrefHeight(GridPane.java:1242)
at javafx.scene.Parent.prefHeight(Parent.java:918)
at javafx.scene.layout.Region.prefHeight(Region.java:1438)
at com.sun.javafx.scene.control.skin.ScrollPaneSkin.computeScrollNodeSize(ScrollPaneSkin.java:916)
at com.sun.javafx.scene.control.skin.ScrollPaneSkin.layoutChildren(ScrollPaneSkin.java:791)
at javafx.scene.control.Control.layoutChildren(Control.java:574)
at javafx.scene.Parent.layout(Parent.java:1076)
at javafx.scene.Parent.layout(Parent.java:1082)
at javafx.scene.Parent.layout(Parent.java:1082)
at javafx.scene.Parent.layout(Parent.java:1082)
at javafx.scene.Parent.layout(Parent.java:1082)
at javafx.scene.Parent.layout(Parent.java:1082)
at javafx.scene.Parent.layout(Parent.java:1082)
at javafx.scene.Parent.layout(Parent.java:1082)
at javafx.scene.Parent.layout(Parent.java:1082)
at javafx.scene.Parent.layout(Parent.java:1082)
at javafx.scene.Parent.layout(Parent.java:1082)
at javafx.scene.Parent.layout(Parent.java:1082)
at javafx.scene.Scene.doLayoutPass(Scene.java:576)
at javafx.scene.Scene$ScenePulseListener.pulse(Scene.java:2386)
at com.sun.javafx.tk.Toolkit$3.run(Toolkit.java:321)
at com.sun.javafx.tk.Toolkit$3.run(Toolkit.java:319)
at java.security.AccessController.doPrivileged(Native Method)
at com.sun.javafx.tk.Toolkit.runPulse(Toolkit.java:319)
at com.sun.javafx.tk.Toolkit.firePulse(Toolkit.java:348)
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.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:745)

As you can see, it's all JavaFX code on the stack, so this is a little
tricky to debug.  As such I'm not sure yet if this is a JavaFX bug
introduced with 8.0 or an application bug that was masked in JavaFX
2.2 and is now showing up in JavaFX 8.

This happens when the managed/visible state of children changes.. but
I think it only for the case when all the children become unmanaged.

Once it happens JavaFX is crippled and pretty much all layout is
broken.  Popups (menus) still work and I can exit the application, but
all layout in the main window seems to not happen anymore.  Manual
positioning of nodes still works though.

I'll try to isolate a reproducible test case and file a bug report of course.

Scott