RFR: 8091673: Public focus traversal API for use in custom controls [v3]

[Michael Strauß]

On Mon, 28 Oct 2024 17:33:46 GMT, Andy Goryachev <angorya at openjdk.org> wrote:

>> Because `focusVisible` is specified to _only_ be set as a result of keyboard navigation, not as a result of programmatic navigation.
>> 
>> `Node.focusVisible` specifies:
>> 
>>     /**
>>      * Indicates whether this {@code Node} should visibly indicate focus.
>>      * This flag is set when the node acquires input focus via keyboard navigation,
>>      * and it is cleared when the node loses focus or when {@link #requestFocus()}
>>      * is called.
>>      *
>>      * @defaultValue false
>>      * @since 19
>>      */
>> 
>> 
>> The [JBS issue](https://bugs.openjdk.org/browse/JDK-8268225) says:
>>> For JavaFX, "Node.focusVisible" would be set in addition to "Node.focused" if a scene graph node gained focus as a consequence of keyboard input. In all other cases, "Node.focusVisible" would not be set on a node.
>
> To clarify, this PR changes nothing in the way FX behaves in relation to focus.  Nothing.  I only provided a public API for use in custom controls. 
> 
> So whatever discrepancy between FX and w3.org spec you mention (not sure why, this isn't an FX spec) applies equally to the existing implementation (if not, please let me know - you found a bug).
> 
> However, perhaps, you pointing out that the docs may be improved - and you are doing so in a very difficult manner.  Or maybe you are pointing out the fact that we should bring back the traverse(Node, TraversalDirection, boolean focusVisible) call?

I just quoted you the JavaFX specification, not W3C. It very clearly says that the `focusVisible` flag is only set when a node acquires focus as a result of keyboard navigation. You are proposing to extend the API to change focus programmatically, and in the process also set `focusVisible`, thus violating that specification.

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PR Review Comment: https://git.openjdk.org/jfx/pull/1604#discussion_r1819482860