On Thu, 8 Aug 2024 20:18:09 GMT, Martin Fox <m...@openjdk.org> wrote:
> For that matter you can't really infer that an event was consumed just > because the dispatch chain returned null. The EventDispatcher documentation > is a little hazy on this but in theory a dispatcher could return null for > other reasons. It seems to be mostly a matter of convention that null > indicates that an event was consumed. It seems much more likely that we could clean this up by explicitly specifying this behavior. Here's what I would do: 1. Implement [JDK-8303209](https://bugs.openjdk.org/browse/JDK-8303209) 2. Specify that `dispatchEvent` must only return `null` if the event was consumed. 3. Explicitly document that `Event.isConsumed()` can only be used inside of an event handler, but not to detect whether an event was consumed at the place where the event is fired. This would be sufficient to solve the problem at hand, and will also enable third-party controls to do the same. Going further, I question whether we need the `isConsumed()` method at all. Consumed events shouldn't be propagated, and the current behavior is very strange to say the least (events on the same level are propagated even though they're consumed). If consumed events are not propagated, there should be no need to check whether an event was consumed. ------------- PR Comment: https://git.openjdk.org/jfx/pull/1523#issuecomment-2277066533
