[RFC] Package of Nomacs

[Leo Prikler <leo.prikler@student.tugraz.at>]

Hi rovanion,

> (define-module (nomacs)
The nomacs package should probably go to gnu/packages/image-
viewers.scm.

>     (source (origin
>               (method url-fetch)
>               (uri (string-append "
> https://codeload.github.com/nomacs/nomacs/tar.gz/" version))
>               (sha256
> "0z113mfxxdy3wafh0g1xxxwsc5qg0n42r4345c6rxvr6h02fkixv")))
Use git-fetch instead and don't recurse into submodules.  You will
likely encounter some errors, because it doesn't seem as though nomacs
expects you to have its inputs properly packages.  *sigh*

>      `(#:configure-flags (list "-DENABLE_TRANSLATIONS=true"
>                                "-DUSE_SYSTEM_QUAZIP=true"
>                                (string-append "../nomacs-" ,version
> "/ImageLounge"))
Instead of adding the path to the source directory, try `(cd
"ImageLounge")` in a phase after 'unpack.

>     (inputs `(("python"     ,python-wrapper)
>               ("qtbase"     ,qtbase)
>               ("qtlinguist" ,qttools)
>               ("qtsvg"      ,qtsvg)
>               ("exiv2"      ,exiv2)
>               ("libtiff"    ,libtiff)
>               ("opencv"     ,opencv)
>               ("libraw"     ,libraw)
>               ("quazip"     ,quazip)))
Try to sort them alphabetically, also don't put too much effort into
making the tails align.

> (description "Nomacs is a free, open source image viewer, which
> supports multiple platforms. You can use it for viewing all common
> image formats including RAW and psd images.
> 
> Nomacs features semi-transparent widgets that display additional
> information such as thumbnails, metadata or histogram. It is able to
> browse images in zip or MS Office files which can be extracted to a
> directory. Metadata stored with the image can be displayed and you
> can add notes to images. A thumbnail preview of the current folder is
> included as well as a file explorer panel which allows switching
> between folders. Within a directory you can apply a file filter, so
> that only images are displayed whose filenames have a certain string
> or match a regular expression. Activating the cache allows for
> instantly switching between images.
> 
> Nomacs includes image manipulation methods for adjusting brightness,
> contrast, saturation, hue, gamma, exposure. It has a pseudo color
> function which allows creating false color images. A unique feature
> of Nomacs is the synchronization of multiple instances. With this
> feature you can easily compare images by zooming and/or panning at
> the exactly same position or even by overlaying them with different
> opacity.
> Nomacs is licensed under the GNU General Public License v3 and
> available for Windows, Linux, FreeBSD, Mac, and OS/2.")
fill-column is at 78.  Also try to shorten this text and use double
spaces ("  ") between sentences.

> (license gpl3)
It is actually gpl3+ according to license/README.md.

> One thing that's missing is the plugins that are developed in a
> separate git repository [0] and not included in the source tarballs
> of the main repository [1]. Ideas on how to make them available in
> the `plugins` directory during build time are welcome.
A trick that's often used in Guix is
(inputs
 `(("extra-source-package"
    ,(origin ...)))
   [other inputs])
You can then (copy-recursively (assoc-ref inputs "extra-source-
package") destination) in a phase between 'unpack and 'configure.

Regards,
Leo