Sometimes when I'm setting the divider positions of a SplitPane programmatically my value gets overridden again by some JavaFX internal layout code.

For debugging purposes I've added a listener to the position property of the divider and have thrown a RuntimeException to see the stack trace. It looks like this:

-----------------------------------------------------------------------------
at
com.sun.javafx.binding.ExpressionHelper$Generic.fireValueChangedEvent(ExpressionHelper.java:361)
        at
com.sun.javafx.binding.ExpressionHelper.fireValueChangedEvent(ExpressionHelper.java:81)
        at
javafx.beans.property.DoublePropertyBase.fireValueChangedEvent(DoublePropertyBase.java:106)
        at
javafx.beans.property.DoublePropertyBase.markInvalid(DoublePropertyBase.java:113)
        at
javafx.beans.property.DoublePropertyBase.set(DoublePropertyBase.java:146)
        at javafx.scene.control.SplitPane$Divider.setPosition(SplitPane.java:486)
        at
com.sun.javafx.scene.control.skin.SplitPaneSkin.setAbsoluteDividerPos(SplitPaneSkin.java:310)
        at
com.sun.javafx.scene.control.skin.SplitPaneSkin.setupContentAndDividerForLayout(SplitPaneSkin.java:502)
        at
com.sun.javafx.scene.control.skin.SplitPaneSkin.layoutChildren(SplitPaneSkin.java:817)
        at javafx.scene.control.Control.layoutChildren(Control.java:589)
        at javafx.scene.Parent.layout(Parent.java:1074)
        at javafx.scene.Parent.layout(Parent.java:1080)
        at javafx.scene.Parent.layout(Parent.java:1080)
        at javafx.scene.Parent.layout(Parent.java:1080)
        at javafx.scene.Parent.layout(Parent.java:1080)
        at javafx.scene.Parent.layout(Parent.java:1080)
        at javafx.scene.Parent.layout(Parent.java:1080)
        at javafx.scene.Parent.layout(Parent.java:1080)
        at javafx.scene.Parent.layout(Parent.java:1080)
        at javafx.scene.Scene.doLayoutPass(Scene.java:532)
        at javafx.scene.Scene$ScenePulseListener.pulse(Scene.java:2363)
        at com.sun.javafx.tk.Toolkit.lambda$runPulse$28(Toolkit.java:314)
        at com.sun.javafx.tk.Toolkit$$Lambda$230/25595560.run(Unknown Source)
        at java.security.AccessController.doPrivileged(Native Method)
        at com.sun.javafx.tk.Toolkit.runPulse(Toolkit.java:313)
        at com.sun.javafx.tk.Toolkit.firePulse(Toolkit.java:340)
        at com.sun.javafx.tk.quantum.QuantumToolkit.pulse(QuantumToolkit.java:451)
        at com.sun.javafx.tk.quantum.QuantumToolkit.pulse(QuantumToolkit.java:431)
        at
com.sun.javafx.tk.quantum.QuantumToolkit.lambda$runToolkit$363(QuantumToolkit.java:298)
        at
com.sun.javafx.tk.quantum.QuantumToolkit$$Lambda$59/174792896.run(Unknown
Source)
        at
com.sun.glass.ui.InvokeLaterDispatcher$Future.run(InvokeLaterDispatcher.java:95)
        at com.sun.glass.ui.gtk.GtkApplication._runLoop(Native Method)
        at
com.sun.glass.ui.gtk.GtkApplication.lambda$null$45(GtkApplication.java:126)
        at com.sun.glass.ui.gtk.GtkApplication$$Lambda$55/1472148546.run(Unknown
Source)
        at java.lang.Thread.run(Thread.java:745)
-----------------------------------------------------------------------------

The two dividers changed during the layoutChildren call as follows:

Divider position changed: old value: 0.10857763300760044, new value: 0.004343105320304018

Divider position changed: old value: 0.8914223669923995, new value: 0.995656894679696