JavaFX ColorPicker NullPointerException

Question

When I click on Custom Color link I get this horrible NullPointerException:

Exception in thread "JavaFX Application Thread" java.lang.NullPointerException
at javafx.stage.Window$9.invalidated(Window.java:867)
at javafx.beans.property.BooleanPropertyBase.markInvalid(BooleanPropertyBase.java:109)
at javafx.beans.property.BooleanPropertyBase.set(BooleanPropertyBase.java:144)
at javafx.stage.Window.setShowing(Window.java:922)
at javafx.stage.Window.show(Window.java:937)
at javafx.stage.Stage.show(Stage.java:259)
at com.sun.javafx.scene.control.skin.CustomColorDialog.show(CustomColorDialog.java:170)
at com.sun.javafx.scene.control.skin.ColorPalette$1.handle(ColorPalette.java:127)
at com.sun.javafx.scene.control.skin.ColorPalette$1.handle(ColorPalette.java:105)
at com.sun.javafx.event.CompositeEventHandler.dispatchBubblingEvent(CompositeEventHandler.java:86)
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.EventUtil.fireEventImpl(EventUtil.java:74)
at com.sun.javafx.event.EventUtil.fireEvent(EventUtil.java:49)
at javafx.event.Event.fireEvent(Event.java:198)
at javafx.scene.Node.fireEvent(Node.java:8411)
at javafx.scene.control.Hyperlink.fire(Hyperlink.java:153)
at com.sun.javafx.scene.control.behavior.ButtonBehavior.mouseReleased(ButtonBehavior.java:182)
at com.sun.javafx.scene.control.skin.BehaviorSkinBase$1.handle(BehaviorSkinBase.java:96)
at com.sun.javafx.scene.control.skin.BehaviorSkinBase$1.handle(BehaviorSkinBase.java:89)
at com.sun.javafx.event.CompositeEventHandler$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.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$MouseHandler.process(Scene.java:3757)
at javafx.scene.Scene$MouseHandler.access$1500(Scene.java:3485)
at javafx.scene.Scene.impl_processMouseEvent(Scene.java:1762)
at javafx.scene.Scene$ScenePeerListener.mouseEvent(Scene.java:2494)
at com.sun.javafx.tk.quantum.GlassViewEventHandler$MouseEventNotification.run(GlassViewEventHandler.java:380)
at com.sun.javafx.tk.quantum.GlassViewEventHandler$MouseEventNotification.run(GlassViewEventHandler.java:294)
at java.security.AccessController.doPrivileged(Native Method)
at com.sun.javafx.tk.quantum.GlassViewEventHandler.lambda$handleMouseEvent$354(GlassViewEventHandler.java:416)
at com.sun.javafx.tk.quantum.QuantumToolkit.runWithoutRenderLock(QuantumToolkit.java:389)
at com.sun.javafx.tk.quantum.GlassViewEventHandler.handleMouseEvent(GlassViewEventHandler.java:415)
at com.sun.glass.ui.View.handleMouseEvent(View.java:555)
at com.sun.glass.ui.View.notifyMouse(View.java:937)
at com.sun.glass.ui.win.WinApplication._runLoop(Native Method)
at com.sun.glass.ui.win.WinApplication.lambda$null$148(WinApplication.java:191)
at java.lang.Thread.run(Thread.java:745)

How it looks:

Is any possibility to fix it? Maybe there is some way to cut that link in the bottom? Code:

colorMenu = new Menu("Color");
    ColorPicker colorPicker = new ColorPicker();
    colorPicker.setValue(Color.FIREBRICK);
    m_palette = new MenuItem(null, colorPicker);
    m_palette.setOnAction(event -> gameScene.setCellColor(colorPicker.getValue()));

Thanks for any advices!

Answer 1

It is possible to remove the offending Hyperlink from the ColorPicker. Here, we make a ColorPicker with our own ColorPickerSkin. We can then intercept the creation of the popup content in the Skin before it is returned in order to remove the Hyperlink.

public class CustomColorPicker extends ColorPicker {

    @Override
    protected Skin<?> createDefaultSkin() {
        return new CustomColorPickerSkin(this);
    }

    private class CustomColorPickerSkin extends ColorPickerSkin {

        public CustomColorPickerSkin(ColorPicker control) {
            super(control);
        }

        @Override
        protected Node getPopupContent() {
            Node colorPalette = super.getPopupContent(); // This is an instance of private API ColorPalette which
                                                            // extends Region
            Region r = (Region) colorPalette;
            List<Node> vboxes = r.getChildrenUnmodifiable().stream().filter(e -> {
                return e instanceof VBox;
            }).collect(Collectors.toList()); // This ColorPalette contains a VBox which contains the Hyperlink we want
                                                // to remove.
            for (Node n : vboxes) {
                VBox vbox = (VBox) n;
                List<Node> hyperlinks = vbox.getChildren().stream().filter(e -> {
                    return e instanceof Hyperlink;
                }).collect(Collectors.toList());
                vbox.getChildren().removeAll(hyperlinks); // Remove the hyperlink
            }
            return colorPalette;
        }

    }

}

This will find and remove any Hyperlinks inside any VBoxes in the ColorPalette. Keep in mind that it will break if the structure of ColorPalette is changed, which is totally possible since it isn't public API.

How it looks:

Answer 2

I avoided this problem by creating Menu object insead of MenuItem. It now looks like this: Screenshot