While developing a framework which subclasses TextField to add additional functionality, I sometimes run into the exception below. There are two problems with this exception:
1. My code is not part of the stack trace, so it is really difficult to figure out what my role in the situation is.
2. The information provided by the exception is very scarce.

It would be great, if this exception was improved with information on what the developer can do to avoid this problem. Also, the start and end values ought to be part of the message, since those values are the cause of the exception. But again, this is very difficult to debug, as this happens inside JavaFX without directly involving application code.

After some debugging I noticed that this exception is thrown by TextInputControl after I type a single key. What happens is this:

1. 19 characters are already input into my TextField.
2. I type "4".
3. TextInputControlBehavior will in line 230 try to get the selection, but since nothing is selected, it gets a range from 19 to 19.
4. Once this range reaches TextInputControl it throws this:

java.lang.IllegalArgumentException: The start must be <= the end
at javafx.scene.control.TextInputControl.getText(TextInputControl.java:446)
at javafx.scene.control.TextInputControl.updateContent(TextInputControl.java:564)
at javafx.scene.control.TextInputControl.replaceText(TextInputControl.java:548)
at com.sun.javafx.scene.control.skin.TextFieldSkin.replaceText(TextFieldSkin.java:576)
at com.sun.javafx.scene.control.behavior.TextFieldBehavior.replaceText(TextFieldBehavior.java:202)
at com.sun.javafx.scene.control.behavior.TextInputControlBehavior.defaultKeyTyped(TextInputControlBehavior.java:238)
at com.sun.javafx.scene.control.behavior.TextInputControlBehavior.callAction(TextInputControlBehavior.java:139)
at com.sun.javafx.scene.control.behavior.BehaviorBase.callActionForEvent(BehaviorBase.java:218)
at com.sun.javafx.scene.control.behavior.TextInputControlBehavior.callActionForEvent(TextInputControlBehavior.java:127)
at com.sun.javafx.scene.control.behavior.BehaviorBase.lambda$new$74(BehaviorBase.java:135)
at com.sun.javafx.event.CompositeEventHandler$NormalEventHandlerRecord.handleBubblingEvent(CompositeEventHandler.java:218)
at com.sun.javafx.event.CompositeEventHandler.dispatchBubblingEvent(CompositeEventHandler.java:80)
at com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(EventHandlerManager.java:238)
at com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(EventHandlerManager.java:191)
at com.sun.javafx.event.CompositeEventDispatcher.dispatchBubblingEvent(CompositeEventDispatcher.java:59)
at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:58)
at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:56)
at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:56)
at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:56)
at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:56)
at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:56)
at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
at com.sun.javafx.event.EventUtil.fireEventImpl(EventUtil.java:74)
at com.sun.javafx.event.EventUtil.fireEvent(EventUtil.java:54)
at javafx.event.Event.fireEvent(Event.java:198)
at javafx.scene.Scene$KeyHandler.process(Scene.java:3964)
at javafx.scene.Scene$KeyHandler.access$1800(Scene.java:3910)
at javafx.scene.Scene.impl_processKeyEvent(Scene.java:2040)
at javafx.scene.Scene$ScenePeerListener.keyEvent(Scene.java:2501)
at com.sun.javafx.tk.quantum.GlassViewEventHandler$KeyEventNotification.run(GlassViewEventHandler.java:216)
at com.sun.javafx.tk.quantum.GlassViewEventHandler$KeyEventNotification.run(GlassViewEventHandler.java:148)
at java.security.AccessController.doPrivileged(Native Method)
at com.sun.javafx.tk.quantum.GlassViewEventHandler.lambda$handleKeyEvent$353(GlassViewEventHandler.java:247)
at com.sun.javafx.tk.quantum.QuantumToolkit.runWithoutRenderLock(QuantumToolkit.java:389)
at com.sun.javafx.tk.quantum.GlassViewEventHandler.handleKeyEvent(GlassViewEventHandler.java:246)
at com.sun.glass.ui.View.handleKeyEvent(View.java:546)
at com.sun.glass.ui.View.notifyKey(View.java:966)