Focus behavior on cell based controls

[Abhinay Agarwal]

Hi Michael,

Thank you for the explanation. I was confused to see focused still set to true on cells,
which is more prominent now with the introduction of `focusWithin`.

Deprecating `Note.setFocused` would need a major update across controls,
whereas an update in Cell to use cell-specific focus property seems harmless.

- Abhinay

> On 22 Nov 2024, at 4:19 PM, Michael Strauß <michaelstrau2 at gmail.com> wrote:
>
> This was an unfortunate decision. The reason for this seems to be that
> cell-based controls use the `focused` property in a non-standard way,
> to remember the focused cell even when the input focus was moved to a
> different control. There's no reason to do that, and can be fixed by
> introducing a cell-specific property for this purpose (maybe
> "retainedFocus", "cellFocus", or something like that). Controls should
> never tamper with focus properties, as these are managed by the Node
> class. We should probably deprecate the `Node.setFocused` method that
> currently allows derived classes to change the focused property.
>
>
> On Fri, Nov 22, 2024 at 11:20 AM Abhinay Agarwal
> <abhinay_agarwal at live.com> wrote:
>>
>> Hi,
>>
>> Controls like ListView, TreeView, etc. always have one of the cells with focused property set to true.
>>
>> This causes the focusWithin property [1] (introduced in 19) on these controls to be set to true even when the actual focus is neither on them nor its children.
>>
>> I wonder if there is a reason for setting the focused property on one the cells always to true?
>>
>> - Abhinay
>>
>> [1] https://openjfx.io/javadoc/23/javafx.graphics/javafx/scene/Node.html#focusWithinProperty