On Sat, 3 Apr 2021 15:20:41 GMT, Michael Strauß <mstra...@openjdk.org> wrote:
> The internal BidirectionalBinding class implements bidirectional bindings for > JavaFX properties. The design intent of this class is to provide > specializations for primitive value types to prevent boxing conversions (cf. > specializations of the Property class with a similar design intent). > > However, the primitive BidirectionalBinding implementations do not meet the > design goal of preventing boxing conversions, because they implement > ChangeListener. > > ChangeListener is a generic SAM interface, which makes it impossibe to invoke > an implementation of ChangeListener::changed with a primitive value (i.e. any > primitive value will be auto-boxed). > > The boxing conversion happens, as with all ChangeListeners, at the invocation > site (for example, in ExpressionHelper). Since the boxing conversion has > already happened by the time any of the BidirectionalBinding implementations > is invoked, there's no point in using primitive specializations of > BidirectionalBinding after the fact. > > This issue can be solved by having BidirectionalBinding implement > InvalidationListener instead, which by itself does not incur a boxing > conversion. Because bidirectional bindings are eagerly evaluated, the > observable behavior remains the same. > > I've filed a bug report with the same title. This pull request has now been integrated. Changeset: 285a0b65 Author: Michael Strauß <mstra...@openjdk.org> Committer: Ambarish Rapte <ara...@openjdk.org> URL: https://git.openjdk.java.net/jfx/commit/285a0b65907e2cf5cd12dec1a88f729ba2c1c9ba Stats: 113 lines in 3 files changed: 44 ins; 5 del; 64 mod 8264770: BidirectionalBinding should use InvalidationListener to prevent boxing Reviewed-by: arapte, kcr ------------- PR: https://git.openjdk.java.net/jfx/pull/454
