NPE at javafx.scene.text.Text.getSpanBounds(Text.java:292)

[miho]

Just tried to use the CodeArea inside a JFXtras-labs 8 window control. Unfortunately I get the following error:

Exception in thread "JavaFX Application Thread" java.lang.NullPointerException
    at javafx.scene.text.Text.getSpanBounds(Text.java:292)
    at javafx.scene.text.Text.impl_computeGeomBounds(Text.java:1146)
    at javafx.scene.Node.updateGeomBounds(Node.java:3526)

JavaFX TextArea and Text nodes do work.

The error does not occur if I prevent layout calls via setManaged(false).

What I do exactly:

CodeArea textArea = new CodeArea();
textArea.replaceText("my code");

Window w = new Window("CodeEditor");
w.setPreferredSize(400,300);

// content pane is a regular stack pane
w.getContentPane().getChildren().add(textArea);

rootPane.getChildren().add(w);

I'm testing on OS X, JDK 8-b129 and the CodeAreaFX from commit b8846ca3e1fba8e4829ee3d015b305b2bf99380c

[TomasMikula]

Can you please post the full code, so that I can try it out? For example, I don't know where rootPane in your example comes from. Can you also point me to the JFXtras-labs JAR you are using?

[miho]

I'll setup a small project to demonstrate the issue.

[miho]

Seems to be related to the ScalableContentPane. I haven't had any issues with applying scale transformations to controls so far.

How To Reproduce:

Before running it, call the fetchDeps task which downloads CodeAreaFX.

Use the withScalableContentPane toggle to change scene setup (with or without ScalableContentPane).

Here's the code: https://gist.github.com/miho/9322527
Complete Project: https://drive.google.com/file/d/0B5SD3655oxUQWVdaaDhRdzlLYzA/edit?usp=sharing

Can you reproduce it?

[TomasMikula]

Thanks for the sample code. Seems to be a TextFlow problem. This is how I changed your code (leaving out CodeArea altogether):

import javafx.application.Application;
import javafx.scene.Scene;
import javafx.scene.layout.Pane;
import javafx.scene.text.Text;
import javafx.scene.text.TextFlow;
import javafx.stage.Stage;
import jfxtras.labs.scene.control.window.CloseIcon;
import jfxtras.labs.scene.control.window.Window;
import jfxtras.labs.scene.layout.ScalableContentPane;

public class Main extends Application {

    /**
     * The main() method is ignored in correctly deployed JavaFX application.
     * main() serves only as fallback in case the application can not be
     * launched through deployment artifacts, e.g., in IDEs with limited FX
     * support. NetBeans ignores main().
     *
     * @param args the command line arguments
     */
    public static void main(String[] args) {
        launch(args);
    }

    @Override
    public void start(Stage primaryStage) {

        // indicates whether to use a scalable content pane
        boolean withScalableContentPane = true;

        // setup scene
        Pane canvas;
        Scene scene;
        if (withScalableContentPane) {
            ScalableContentPane root = new ScalableContentPane();
            canvas = root.getContentPane();
            scene = new Scene(root, 800, 600);
        } else {
            canvas = new Pane();
            scene = new Scene(canvas, 800, 600);
        }

        // add a window that contains a TextFlow
        TextFlow textFlow = new TextFlow(new Text("The Code"));
        Window w = new Window("Editor");
        w.getLeftIcons().add(new CloseIcon(w));
        w.setPrefSize(400, 300);
        w.getContentPane().getChildren().add(textFlow);
        canvas.getChildren().add(w);

        // show the stage
        primaryStage.setTitle("Demo!");
        primaryStage.setScene(scene);
        primaryStage.show();

    }
}

When I run this, I actually get an infinite loop of exceptions.

Another observation I made is that the combination of ScalableContentPane and Window is required to reproduce the bug. Adding the TextFlow (or CodeArea) directly to canvas works.

I'm going to close this. When the problem with TextFlow is fixed and the problem with CodeArea does not go away, please reopen.

[miho]

Thanks for your response!

I found a workaround for the TextFlow case by invoking layout() after instantiaton:

    TextFlow codeArea = new TextFlow(new Text("The Code"));
    codeArea.layout(); // fixes the problem

Unfortunately this does not work for CodeArea.

[TomasMikula]

I reported this to OpenJFX: RT-36130.

[miho]

Thanks!

[miho]

Unfortunately, the CodeArea still does not work with the ScalableContentPane. With 8u20 the error is different:

    Exception in thread "JavaFX Application Thread" java.lang.ArrayIndexOutOfBoundsException: -1
    at java.util.ArrayList.elementData(ArrayList.java:418)
    at java.util.ArrayList.get(ArrayList.java:431)
    at com.sun.javafx.collections.ObservableListWrapper.get(ObservableListWrapper.java:89)
    at com.sun.javafx.collections.VetoableListDecorator.get(VetoableListDecorator.java:306)
    at javafx.scene.Parent.updateCachedBounds(Parent.java:1579)
    at javafx.scene.Parent.recomputeBounds(Parent.java:1523)
    at javafx.scene.Parent.impl_computeGeomBounds(Parent.java:1374)
    at javafx.scene.layout.Region.impl_computeGeomBounds(Region.java:3022)
    at javafx.scene.Node.updateGeomBounds(Node.java:3552)
    at javafx.scene.Node.getGeomBounds(Node.java:3505)
    at javafx.scene.Node.getLocalBounds(Node.java:3453)
    at javafx.scene.Node.updateTxBounds(Node.java:3616)
    at javafx.scene.Node.getTransformedBounds(Node.java:3399)
    at javafx.scene.Parent.recomputeBounds(Parent.java:1510)
    at javafx.scene.Parent.impl_computeGeomBounds(Parent.java:1374)
    at javafx.scene.layout.Region.impl_computeGeomBounds(Region.java:3022)
    at javafx.scene.Node.updateGeomBounds(Node.java:3552)
    at javafx.scene.Node.getGeomBounds(Node.java:3505)

I'd love to use RichTextFX for my JavaOne Live Demos. Any ideas?

Note: it works with TextFlow

[TomasMikula]

Is this with the latest 0.4.2 version?

[miho]

0.4.2 and 1.0-SNAPSHOT

[TomasMikula]

Hi Michael,

I did some digging and the following might be the cause of this exception, but certainly is a bug in JFXtras' Window.

Node.boundsInParentProperty's Javadoc says

Note that boundsInParent is automatically recomputed whenever the geometry of a node changes, or when any of the following the change: transforms ObservableList, translateX, translateY, layoutX, layoutY, scaleX, scaleY, or the rotate variable. For this reason, it is an error to bind any of these values in a node to an expression that depends upon this variable. For example, the x or y variables of a shape, or translateX, translateY should never be bound to boundsInParent for the purpose of positioning the node.

However, Window.java sets layoutX and layoutY from a boundsInParent listener, which is an error per the above Javadoc comment.

[miho]

Thanks for this hint! Looks like we produce event garbage in the window control.

[miho]

It works! Thanks again. Just in case anybody else is having this issue: use the window control from jfxtras-window instead of the one from jfxtras-labs. It does not have the issue mentioned by Tomas.