RangeSlider verursacht NullPointerException beim Drücken der Tabulatortaste auf dem Fokus-Schieberegler

Question

Ich bekomme NullPointerException, wenn org.controlsfx.control.RangeSlider verwendet wird. Hier ist die einfache Codebeispiel:

package experimental_main; 

import org.controlsfx.control.RangeSlider; 

import javafx.application.Application; 
import javafx.scene.Scene; 
import javafx.scene.control.Button; 
import javafx.scene.layout.BorderPane; 
import javafx.stage.Stage; 


public class Experimental_start extends Application 
{ 
    public static void main(String[] args) 
    { 
     launch(args); 
    } 


    @Override 
    public void start(Stage primaryStage) throws Exception 
    { 
     Button button = new Button("Click me"); 
     RangeSlider rangeSlider = new RangeSlider(0, 10, 2, 4); 

     BorderPane borderPane = new BorderPane(); 
     borderPane.setCenter(rangeSlider); 
     borderPane.setTop(button); 

     Scene scene = new Scene(borderPane, 300, 300); 
     primaryStage.setScene(scene); 
     primaryStage.show(); 
    } 
} 

Die Ausnahme tritt auf, wenn Tab drücken, während Daumen der rechten Hand von RangeSlider fokussiert ist oder Drücken von Shift + Tab, während seine linke Daumen konzentriert. Diese Tastenbetätigungen führen dazu, dass der Fokus von RangeSlider wie erwartet verloren geht, aber diese Aktion verursacht auch NullPointerException. Hier Ausnahme der Stack-Trace:

Exception in thread "JavaFX Application Thread" java.lang.NullPointerException 
at com.sun.javafx.scene.traversal.TraversalEngine.select(Unknown Source) 
at impl.org.controlsfx.skin.RangeSliderSkin$5.handle(RangeSliderSkin.java:150) 
at impl.org.controlsfx.skin.RangeSliderSkin$5.handle(RangeSliderSkin.java:132) 
at com.sun.javafx.event.CompositeEventHandler$NormalEventHandlerRecord.handleBubblingEvent(Unknown Source) 
at com.sun.javafx.event.CompositeEventHandler.dispatchBubblingEvent(Unknown Source) 
at com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(Unknown Source) 
at com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(Unknown Source) 
at com.sun.javafx.event.CompositeEventDispatcher.dispatchBubblingEvent(Unknown Source) 
at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(Unknown Source) 
at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(Unknown Source) 
at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(Unknown Source) 
at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(Unknown Source) 
at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(Unknown Source) 
at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(Unknown Source) 
at com.sun.javafx.event.EventUtil.fireEventImpl(Unknown Source) 
at com.sun.javafx.event.EventUtil.fireEvent(Unknown Source) 
at javafx.event.Event.fireEvent(Unknown Source) 
at javafx.scene.Scene$KeyHandler.process(Unknown Source) 
at javafx.scene.Scene$KeyHandler.access$1800(Unknown Source) 
at javafx.scene.Scene.impl_processKeyEvent(Unknown Source) 
at javafx.scene.Scene$ScenePeerListener.keyEvent(Unknown Source) 
at com.sun.javafx.tk.quantum.GlassViewEventHandler$KeyEventNotification.run(Unknown Source) 
at com.sun.javafx.tk.quantum.GlassViewEventHandler$KeyEventNotification.run(Unknown Source) 
at java.security.AccessController.doPrivileged(Native Method) 
at com.sun.javafx.tk.quantum.GlassViewEventHandler.lambda$handleKeyEvent$353(Unknown Source) 
at com.sun.javafx.tk.quantum.QuantumToolkit.runWithoutRenderLock(Unknown Source) 
at com.sun.javafx.tk.quantum.GlassViewEventHandler.handleKeyEvent(Unknown Source) 
at com.sun.glass.ui.View.handleKeyEvent(Unknown Source) 
at com.sun.glass.ui.View.notifyKey(Unknown Source) 
at com.sun.glass.ui.win.WinApplication._runLoop(Native Method) 
at com.sun.glass.ui.win.WinApplication.lambda$null$148(Unknown Source) 
at java.lang.Thread.run(Unknown Source) 

Es gibt keine Ausnahme, wenn das Drücken der Tabulatortaste (oder Shift + Tab) mit Blick RangeSlider Daumen zu machen konzentriert.

Mache ich etwas falsch oder es ist ein Fehler? Gibt es eine Alternative zu den Realisierungen der RangeSlider-Klasse?

Answer 1

Dieser Hörer des RangeSliderSkin scheint die NPE zu verursachen:

EventHandler<KeyEvent> keyEventHandler = new EventHandler<KeyEvent>() { 
      @Override public void handle(KeyEvent event) { 
       if (KeyCode.TAB.equals(event.getCode())) { 
        if (lowThumb.isFocused()) { 
         if (event.isShiftDown()) { 
          lowThumb.setFocus(false); 
          new ParentTraversalEngine(rangeSlider).select(rangeSlider, Direction.PREVIOUS); 
         } else { 
          lowThumb.setFocus(false); 
          highThumb.setFocus(true); 
         } 
         event.consume(); 
        } else if (highThumb.isFocused()) { 
         if(event.isShiftDown()) { 
          highThumb.setFocus(false); 
          lowThumb.setFocus(true); 
         } else { 
          highThumb.setFocus(false); 
          new ParentTraversalEngine(rangeSlider).select(rangeSlider, Direction.NEXT); 
         } 
         event.consume(); 
        } 
       } 
      } 
     }; 

Um genauer zu sein, die Linie new ParentTraversalEngine(rangeSlider).select(rangeSlider, Direction.NEXT); ParentTraversalEngine wird initialisiert ohne Algorithm Argument, so ruft select(rangeSlider, Direction.NEXT) ein NPE verursacht, wie es ist soll:

Würfe: java.lang.NullPointerException - wenn es keinen Algorithmus

javadoc

Answer 2

Der Fehler ist fest Beginn ab Version 8.40.13.