I agree that we should only seal existing classes that could not have
been extended by application classes. The ones I listed in my previous
email fit that bill, since an attempt to subclass them will throw an
exception when it is used in a scene graph. Each documents that
subclassing is disallowed.
Btw, we've already started making use of pattern-matching instanceof in
the implementation anyway. It would be the first API change that relies
on a JDK 17 feature, but for JavaFX 21, I see no problem in doing that.
-- Kevin
On 2/1/2023 9:06 AM, Philip Race wrote:
In the JDK we've only sealed existing classes which provably could
not have been extended by application classes,
so I'm not sure about this ..
also I think that might be the first change that absolutely means FX
21 can only be built with JDK 17 and later ..
-phil
On 2/1/23 8:59 AM, Thiago Milczarek Sayão wrote:
Yes, sorry, I made the email title in plural, but I meant what
Michael said, Node would be sealed permitting only what is needed for
JavaFx internally.
-- Thiago
Em qua., 1 de fev. de 2023 às 13:48, Michael Strauß
<michaelstr...@gmail.com> escreveu:
I don't think that's what Thiago is proposing. Only `Node` would
be sealed.
The following subclasses would be non-sealed: Parent, SubScene,
Camera, LightBase, Shape, Shape3D, Canvas, ImageView.
And then there are additional subclasses, which don't fit into this
idea since they are in other modules: SwingNode (in javafx.swing),
MediaView (in javafx.media), Printable (in javafx.web).
On Wed, Feb 1, 2023 at 5:39 PM John Hendrikx
<john.hendr...@gmail.com> wrote:
>
> I think this may be a bit unclear from this post, but you're
proposing I think to make `Node`, `Shape` and `Shape3D` sealed.
For those unaware, you're not allowed to extend these classes
(despite being public). For example Node says in its documentation:
>
> * An application should not extend the Node class directly.
Doing so may lead to
> * an UnsupportedOperationException being thrown.
>
> Currently this is enforced at runtime in NodeHelper.
>
> --John
>
> On 01/02/2023 15:47, Thiago Milczarek Sayão wrote:
>
> Hi,
>
> NodeHelper.java has this:
>
> throw new UnsupportedOperationException(
> "Applications should not extend the "
> + nodeType + " class directly.");
>
>
> I think it's replaceable with selead classes. Am I right?
>
> The benefit will be compile time error instead of runtime.
>
>
> -- Thiago.
>
