On Tue, 20 Jan 2026 19:25:42 GMT, Andy Goryachev <[email protected]> wrote:
> > JavaFX already has this concept today, but we're not using the `Property`
> > API to model it. Layout constraints like `GridPane.columnIndex` or
> > `HBox.margin` are implemented as static getter/setter pairs. Since they are
> > not first-class properties, you don't get any of the nice property features
> > (bindings, listeners, styling, etc).
>
> I always found this design to be weird and unnecessary - these should be the
> properties/constraints of the container or the layout, not something stored
> in the child nodes. What happens when the said child is moved from one
> container to another??
>
> It might be just me, but I fail to see the value of this proposal.
This is basically the JavaFX way to attach layout information to nodes, used by
`GridPane`, `HBox`, `StackPane`, etc. In Swing this is handled differently by
making layout constraints a 2nd parameter when adding a node (like
`GridBagConstraints`), in FX this is done via the general `Properties` map
which is much more flexible. Extending this system so they become full,
observable properties, and even styleable properties is a very logical step.
Making them styleable for example will allow you to move them to CSS:
.button {
-fx-hbox-margin: 10 10 10 10;
-fx-hbox-hgrow: ALWAYS;
}
This is currently one of the biggest missing features when it comes to styling
controls, having to go to programmatic configuration for these kinds of styling
properties.
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PR Comment: https://git.openjdk.org/jfx/pull/2015#issuecomment-3775047169
