On Wed, 10 Jan 2024 02:36:32 GMT, Philippe Altherr <d...@openjdk.org> wrote:
> 8324797: Code example in JavaDoc of ObservableValue#when doesn't compile If I can file the bug, I'm glad to do it. It's a tiny bug. I noticed it while looking into Java FX for a new project. As I had no experience of FX, it wasn't immediately clear to me how to fix the example. Once I got the answer, I thought that I could as well quickly fix the documentation... I did a quick search to see if there other instances of the same problem under [jfx/modules...](https://github.com/openjdk/jfx/blob/master/modules/). I didn't find any but I noticed that [here](https://github.com/openjdk/jfx/blob/37d7561c390f706b9e711dd535580fe5ae76e879/modules/javafx.base/src/main/java/javafx/beans/value/ObservableValue.java#L160) and [here](https://github.com/openjdk/jfx/blob/37d7561c390f706b9e711dd535580fe5ae76e879/modules/javafx.base/src/main/java/javafx/beans/value/ObservableValue.java#L191) in the same file you have the same issue and avoid it by using a `var`, which looks cleaner. My fix should probably do the same. Below is the current code of the example. None of the calls to `setValue` compile. ObservableValue<Boolean> condition = new SimpleBooleanProperty(true); ObservableValue<String> longLivedProperty = new SimpleStringProperty("A"); ObservableValue<String> whenProperty = longLivedProperty.when(condition); // observe whenProperty, which will in turn observe longLivedProperty whenProperty.addListener((ov, old, current) -> System.out.println(current)); longLivedProperty.setValue("B"); // "B" is printed condition.setValue(false); // After condition becomes false, whenProperty stops observing longLivedProperty; condition // and whenProperty may now be eligible for GC despite being observed by the ChangeListener longLivedProperty.setValue("C"); // nothing is printed longLivedProperty.setValue("D"); // nothing is printed condition.setValue(true); // longLivedProperty is observed again, and "D" is printed I have enabled workflows. I have also filed an issue but it looks like this will go through a review of its own: review ID : 9076496 :-( In retrospect, I should have added a link to this PR. modules/javafx.base/src/main/java/javafx/beans/value/ObservableValue.java line 275: > 273: * For example: > 274: * <pre>{@code > 275: * Property<Boolean> condition = new SimpleBooleanProperty(true); A better alternative might be to use a `var` like at line 160 and 191. ------------- PR Comment: https://git.openjdk.org/jfx/pull/1325#issuecomment-1912611708 PR Comment: https://git.openjdk.org/jfx/pull/1325#issuecomment-1913185906 PR Comment: https://git.openjdk.org/jfx/pull/1325#issuecomment-1913190765 PR Review Comment: https://git.openjdk.org/jfx/pull/1325#discussion_r1468536432
