Proposal: Bump minimum JDK version for JavaFX 20 to JDK 17

[John Hendrikx]

I'm split on this myself :)

As JavaFX is more of a library now, and not part of the JDK, allowing 
broader compatibility could be beneficial: people can get new JavaFX 
features without having to upgrade the JDK (each time) as well.  For me 
personally, that is moot since I tend to just track the latest JDK 
release that has features I want, but this might not be the case for 
other (corporate?) JavaFX users. Some small inconveniences in the JavaFX 
code base to appeal to a broader audience could be good.

 From a developer perspective, the new features are compelling, records 
and cast-free instanceof will be nice, but it is not the end of the 
world to live without them for a bit longer.

For something like JavaFX, a middle ground might be good, where it 
tracks the latest LTS (11, 17, 21, etc...)

My 2 cents,

--John

On 19/07/2022 15:44, Kevin Rushforth wrote:
> Even though we build JavaFX binaries with JDK 18 as the boot JDK, the 
> latest version of JavaFX still runs with JDK 11 (and is capable of 
> being built using JDK 12 or later, and with some limitations, using 
> JDK 11), although it isn't tested with older JDK versions. In order 
> for JavaFX to be able to use newer JDK features, such as records, 
> switch expressions, text blocks, and so forth, we need to increase the 
> minimum version of the JDK that can run the latest JavaFX. 
> Additionally, there is an ongoing cost to keeping JavaFX buildable and 
> runnable on older versions of Java, and very little reason to continue 
> to do so.
>
> To this end, I propose to bump the minimum version of the JDK needed 
> to run JavaFX 20 to JDK 17. I filed JDK-8290530 [1] to track this. 
> This will not affect update releases of earlier versions of JavaFX 
> (e.g., JavaFX 17.0.NN), which will continue to run with the same 
> minimum JDK that they run on today.
>
> As a reminder, we only assure that JavaFX NN will run with JDK NN-1 or 
> later, although in practice, we haven't bumped the minimum required 
> JDK version in several releases. So, while JavaFX 19 is built using 
> JDK 18 as the boot JDK, it produces class files that will run with JDK 
> 11, using "--source 11 --target 11". The proposed change discussed 
> here would update that in JavaFX 20 to "--source 17 --target 17".
>
> NOTE: this will not be an invitation to do wholesale refactoring of 
> existing classes or methods to use newer language features (e.g., a PR 
> that turns a bunch of existing data classes into records would not be 
> welcome). Rather, this can be seen as enabling judicious use of new 
> features in new code, much as we did when we started allowing the use 
> of "var".
>
> Absent a compelling reason to remain stuck in the past, I plan to send 
> out a pull request for this change next week.
>
> Comments are welcome.
>
> -- Kevin
>
> [1] https://bugs.openjdk.org/browse/JDK-8290530
>