[External] : Re: RFC: new property in ToggleGroup

[Andy Goryachev]

It is indeed the same in Swing: the initial state for a ButtonGroup is all deselected.  Kevin brought up a good example with HTML radio buttons - in effect saying that this initial state indicates that the user needs to make a choice, which is the most frequent case in an HTML page.

However, it may or may not be the case in FX.  Consider, for example, a case where a file viewer presents a number of modes - (text | hex | image) to present a file.  These modes are mutually exclusive (thus requiring RadioMenuItems or ToggleButtons), but one *must* be selected initially, since it does not make sense to ask the user to make a choice, instead a default choice must be made by the application.

Yes, it can be simply solved by making a default one selected in the code, and that is what is usually done.  I just thought that having a property would eliminate extra code.  One can also extend ToggleGroup to provide that functionality, and that is what I have done in the past.

Thank you all for the discussion and insightful comments.  Given the negative feedback and availability of easy workaround I withdraw this RFC.

Cheers,
-andy



From: Nir Lisker <nlisker at gmail.com>
Date: Saturday, 2023/01/21 at 08:22
To: Kevin Rushforth <kevin.rushforth at oracle.com>
Cc: Andy Goryachev <andy.goryachev at oracle.com>, openjfx-dev at openjdk.org <openjfx-dev at openjdk.org>
Subject: [External] : Re: RFC: new property in ToggleGroup
I don't see it being especially useful. GUI's tend to work this way. I remember it was the same in Swing.

On Sat, Jan 21, 2023 at 1:41 AM Kevin Rushforth <kevin.rushforth at oracle.com<mailto:kevin.rushforth at oracle.com>> wrote:

On 1/20/2023 2:57 PM, Andy Goryachev wrote:
I just want to add one thing - the initial state of RadioMenuItems added to a menu is unselected, even if they belong to a ToggleGroup.

One can say that having all unselected radio buttons in a toggle group makes no sense, or perhaps it depends on the application requirements - though I cannot find an example where it might be needed.

Yes, it's initially unselected unless the app makes an explicit selection. HTML radio buttons work the same way [1]. Some apps use that to indicate that nothing was selected, but then once you select it there will always be something selected.




So either we allow two different policies by adding a property to the ToggleGroup, or we proclaim that adding a radio button to a toggle group must have a side effect of one (first) button to be automatically selected, otherwise the whole group is in inconsistent state (or the app developer must write some code to select one).

I wouldn't want to change the default behavior, since I can imagine some apps relying on being able to tell if the user has ever selected any of the choices.

Having two properties would be one solution, presuming we think that we need to provide a way for the app to indicate that it wants us to enforce the invariant of ensuring that the app can't ever get the control in a state where nothing is selected. Although, since it would be an opt-in, the app could just as easily set the default itself as opposed to setting this new  property.

-- Kevin

[1] https://www.w3schools.com/tags/tryit.asp?filename=tryhtml5_input_type_radio<https://urldefense.com/v3/__https:/www.w3schools.com/tags/tryit.asp?filename=tryhtml5_input_type_radio__;!!ACWV5N9M2RV99hQ!IHUhh-zd22k26dpWxaIMIQPWkUKslHglTRC3u7NgvYYyYi4ZLWiijdogZwo2f9iRPTRGkKW9kGAzk6Vz7Whx$>



-andy




From: openjfx-dev <openjfx-dev-retn at openjdk.org><mailto:openjfx-dev-retn at openjdk.org> on behalf of Kevin Rushforth <kevin.rushforth at oracle.com><mailto:kevin.rushforth at oracle.com>
Date: Friday, 2023/01/20 at 12:27
To: openjfx-dev at openjdk.org<mailto:openjfx-dev at openjdk.org> <openjfx-dev at openjdk.org><mailto:openjfx-dev at openjdk.org>
Subject: Re: RFC: new property in ToggleGroup
How common a UI feature is being able to deselect the selected item in a ToggleGroup via the UI such that no item is selected? I don't normally see that in various apps or toolkits that I am familiar with. What I do see is that either a default item is selected or no item is selected initially (which is the one and only time that there will be no item selected), but in both case, once you make a selection, there is no way via the UI to deselect the current item. Absent a compelling need, I think the current behavior (once the fix for JDK-8237505 is integrated) is sufficient.

What do other developers think?

-- Kevin
On 1/20/2023 11:31 AM, Andy Goryachev wrote:
Dear colleagues:

In the context of a recent PR

https://bugs.openjdk.org/browse/JDK-8237505
https://github.com/openjdk/jfx/pull/1002<https://urldefense.com/v3/__https:/github.com/openjdk/jfx/pull/1002__;!!ACWV5N9M2RV99hQ!IHUhh-zd22k26dpWxaIMIQPWkUKslHglTRC3u7NgvYYyYi4ZLWiijdogZwo2f9iRPTRGkKW9kGAzkyU-UIVq$>
https://stackoverflow.com/questions/57911107/javafx-togglegroup-not-functioning-properly-with-accelerators-radiomenuitem<https://urldefense.com/v3/__https:/stackoverflow.com/questions/57911107/javafx-togglegroup-not-functioning-properly-with-accelerators-radiomenuitem__;!!ACWV5N9M2RV99hQ!IHUhh-zd22k26dpWxaIMIQPWkUKslHglTRC3u7NgvYYyYi4ZLWiijdogZwo2f9iRPTRGkKW9kGAzk5wy-flH$>

where a number of RadioMenuItems belonging to a toggle group are added to the menu, we might want to add a new property to the ToggleGroup which controls whether all items in a group can be deselected.

If this property is set, a selected radio menu item can be deselected via either keyboard accelerator or a mouse click.  If not, then not only this operation cannot be performed, but also the first item added to said ToggleGroup gets automatically selected.

This should allow for more flexibility in creating menus with RadioMenuItems, but eliminate some boilerplate code required in such cases.

The new logic would also affect any Toggle, such as ToggleButton.

What do you think?  Thank you.

-andy


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