handle css resources declared as classpath resource

[McFoggy]

People reported me they were using CSS like

scene.getStylesheets().add("/styles/main.css")

instead of using a URL.

The JavaFX CSS reference guide says that CSS should be referenced by URL.

Not clear yet if we have to support it or not.

[mkpaz]

I'm not sure why it's not implemented. Imo, placing plain CSS file to the app classpath, namely target/classes, is the simplest and most obvious way to play with theming your app. No need to build JAR and no need to install it to local Maven repo. But CSSFX has no built-in converter to handle simple file urls. Anyway, it's easy enough to create one:

URIToPathConverter fileUrlConverter = uri -> {
    try {
        if (uri != null && uri.startsWith("file:")) {
            return Paths.get(URI.create(uri));
        }
    } catch (Exception e) {
        e.printStackTrace();
    }

    return null;
};

CSSFX.addConverter(fileUrlConverter).start();