RFR: 8290040: Provide simplified deterministic way to manage listeners [v6]

[Nir Lisker]

On Tue, 25 Oct 2022 21:06:15 GMT, Nir Lisker <nlisker at openjdk.org> wrote:

>> John Hendrikx has updated the pull request with a new target base due to a merge or a rebase. The pull request now contains ten commits:
>> 
>>  - Merge remote-tracking branch 'origin/master' into
>>    feature/conditional-bindings
>>    
>>    # Conflicts:
>>    #	modules/javafx.base/src/test/java/test/javafx/beans/value/LazyObjectBindingTest.java
>>  - Fix review comments
>>  - Add missing new line
>>  - Small wording fixes
>>  - Update javadoc of "when" with better phrasing
>>  - Rename showing property to shown as it is already used in subclasses
>>  - Add conditional bindings to ObservableValue
>>  - Change explanatory comment to block comment
>>  - Fix bug where ObjectBinding returns null when revalidated immediately
>>    
>>    Introduced with the fluent bindings PR
>
> modules/javafx.graphics/src/main/java/javafx/scene/Node.java line 1415:
> 
>> 1413:      *
>> 1414:      * <p>Note that the {@code Node} does not need to be visible for this property
>> 1415:      * to be {@code true}.
> 
> I think that the definition of "shown" is important enough to make it the main focus of the description with something like:
> 
> 
> Indicates whether or not this {@code Node} is shown. A node is considered shown if it's
> part of a {@code Window} whose {@link shown #Window::showingProperty} is {@code true}.
> The {@link visibility #visibleProperty} of the node or its scene do not affect this property.
> 
> 
> I think that there's no need to repeat the showing conditions for a window.
> Also we need to be careful not to confuse `shown` with `showing`, which are properties on `ComboBox`, `ChoiceBox` and others.

We might also want to add a paragraph explaining its use. Something like:

This property can be used in conjunction with {@link ObservableValue#when}
as a source for listeners that should be collected when the node is not shown.

If there are other uses we can mention them as well.

-------------

PR: https://git.openjdk.org/jfx/pull/830