Disabling customization items

Disabling customization items

[Bill Wohler]

How does one disable items in the customization interface?

Let's say I have the option foo with three features "a", "b", or "c".

    (defcustom foo "a" nil
      :type '(choice (const "a")
                     (const "b")
                     (const "c")))

Let's say feature "b" is not available on a system. I'd like to indicate that
that item is supported by my code, but not by the system. Thus, choice "b"
should be disabled.

Thus customization interface in 21.2 doesn't appear to support this. Has
anyone figured out how to do this?

-- 
Bill Wohler <wohler@newt.com>  http://www.newt.com/wohler/  GnuPG ID:610BD9AD
Maintainer of comp.mail.mh FAQ and MH-E. Vote Libertarian!
If you're passed on the right, you're in the wrong lane.

Re: Disabling customization items

[Kevin Rodgers]

Bill Wohler wrote:

> How does one disable items in the customization interface?
> 
> Let's say I have the option foo with three features "a", "b", or "c".
> 
>     (defcustom foo "a" nil
>       :type '(choice (const "a")
>                      (const "b")
>                      (const "c")))
> 
> Let's say feature "b" is not available on a system. I'd like to indicate that
> that item is supported by my code, but not by the system. Thus, choice "b"
> should be disabled.
> 
> Thus customization interface in 21.2 doesn't appear to support this. Has
> anyone figured out how to do this?

It's not dynamic, but it should be good enough for the situation you've described:


(defcustom foo "a" nil
   :type `(choice (const "a")
		 ,@(if (featurep 'b) (list '(const "b")))
		 (const "c")))

-- 
Kevin Rodgers

Re: Disabling customization items

[Bill Wohler]

Kevin Rodgers <ihs_4664@yahoo.com> writes:

> Bill Wohler wrote:
>
>> How does one disable items in the customization interface?
>> Let's say I have the option foo with three features "a", "b", or "c".
>>     (defcustom foo "a" nil
>>       :type '(choice (const "a")
>>                      (const "b")
>>                      (const "c")))
>> Let's say feature "b" is not available on a system. I'd like to
>> indicate that
>> that item is supported by my code, but not by the system. Thus, choice "b"
>> should be disabled.
>> Thus customization interface in 21.2 doesn't appear to support this.
>> Has
>> anyone figured out how to do this?
>
> It's not dynamic, but it should be good enough for the situation you've described:
>
>
> (defcustom foo "a" nil
>    :type `(choice (const "a")
> 		 ,@(if (featurep 'b) (list '(const "b")))
> 		 (const "c")))

Thanks for your reply Kevin, but I don't think this is what I'm
looking for. I think your code makes item "b" go away entirely.
Instead, I want all three items to appear in the menu, but I want item
"b" to be greyed out and not selectable. Any thoughts about that?

-- 
Bill Wohler <wohler@newt.com>  http://www.newt.com/wohler/  GnuPG ID:610BD9AD
Maintainer of comp.mail.mh FAQ and MH-E. Vote Libertarian!
If you're passed on the right, you're in the wrong lane.