Re: [PATCH] profiles: Add 'hicolor' and 'HighContrast' icon theme hooks.

[ludo@gnu.org (Ludovic Courtès)]

宋文武 <iyzsong@gmail.com> skribis:

> This is WIP.
>> * guix/profiles.scm (gtk-icon-theme-hook): New function.
>>   (%default-profile-hooks): Add `(gtk-icon-theme-hook "hicolor")' and
>>   `(gtk-icon-theme-hook "HighContrast")'.

Looks nice!

>> +(define (gtk-icon-theme-hook name)
>> +  "Return a profile hook that unions all NAME icons from manifest entries and
>> +rebuilds the 'icon-theme.cache' file for the NAME icon theme."
>> +  (define gtk+
>> +    (module-ref (resolve-interface '(gnu packages gtk)) 'gtk+))
>> +
>> +  (lambda (manifest)
>> +    (define build
>> +      #~(begin
>> +          (use-modules (guix build utils)
>> +                       (guix build union))
>> +          (let* ((icon-dir (lambda (base)
>> +                             (string-append base "/share/icons/" #$name)))
>> +                 (destdir  (icon-dir #$output))
>> +                 (icons    (filter
>> +                            file-exists?
>> +                            (map icon-dir '#$(manifest-inputs manifest))))
>> +                 (update-icon-cache (string-append
>> +                                     #+gtk+ "/bin/gtk-update-icon-cache")))
>> +            ;; mkdir -p $out/share/icons
>> +            (mkdir-p destdir)
>> +            (rmdir destdir)
>> +            ;; Unions all the icons and update the 'icon-theme.cache'.
>> +            (union-build destdir icons)
>> +            (system* update-icon-cache "-t" destdir))))
>> +
>> +    (gexp->derivation (string-append (string-downcase name) "-icon-theme")
>> +                      build
>> +                      #:modules '((guix build utils)
>> +                                  (guix build union))
>> +                      #:local-build? #t)))
> When to exclude this derivation?
>
> 1. the best would be whether icon dir exists or not
>    but is this posibble to implement? and how?

Currently this is not possible.  The builder could depend on all the
manifest entries and scan them for share/icons directory, but at this
point it’s already too later because the build has to depend on GTK+.

> 2. whether we have a gtk+ package in profile

That’s no usually the case.  For instance, I have Evince and GIMP in my
profile, but not GTK+.

What could be done is to check whether GTK+ appears and an direct or
indirect dependency of the packages being installed.

Currently manifest entries can contain either a package object or a
store path.  In the former case, one has to use package->bag and then
look for GTK+ in the bag’s transitive inputs.  In the latter, case, one
needs to call ‘references’ to check whether the store item, which is
already built, depends on GTK+.

When none of the manifest’s packages depends on GTK+, then the hook can
just return #f, like ghc-package-cache-file does.

Does that make sense?

>>  (define %default-profile-hooks
>>    ;; This is the list of derivation-returning procedures that are called by
>>    ;; default when making a non-empty profile.
>>    (list info-dir-file
>>          ghc-package-cache-file
>> -        ca-certificate-bundle))
>> +        ca-certificate-bundle
>> +        (gtk-icon-theme-hook "hicolor")
>> +        (gtk-icon-theme-hook "HighContrast")))
> Does these 2 enough?  I think in practical, it does.
> Or (better) as Federico Beffa said in:
>
>   http://lists.gnu.org/archive/html/guix-devel/2015-01/msg00108.html
>
> We should rebuilds all the icon themes?
> If so, I think the code will be more complex...

Let’s have an incremental approach and start with the simple yet helpful
approach that you propose.  We can improve later.

Thoughts?

Thanks,
Ludo’.