From @tephenforpre@ident @ending from gm@il@com  Mon Jul 30 02:02:38 2018
From: @tephenforpre@ident @ending from gm@il@com (Stephen Marsh)
Date: Sun, 29 Jul 2018 20:02:38 -0400
Subject: [Rd] Possible To Enable Building R With Cairo But Without X11
 Dependencies?
In-Reply-To: <23385.9553.581811.803017@rob.eddelbuettel.com>
References: <CAP1gB3dPwmpXCORG11PTKB2by5CJj0LxpHosbAj=G_6Y8m7QXA@mail.gmail.com>
 <23385.9553.581811.803017@rob.eddelbuettel.com>
Message-ID: <CAP1gB3dXLcBBXZjb1VzdxUfWmwds7bs9Rw4PjowfmPwPpEDS3A@mail.gmail.com>

Thanks for the reply, Dirk.  It sounds like xvfb-run is a great solution
when you want R to assume an X window system is present but isn?t?

I think what I'm trying to figure out, and propose for the community to
possibly fix, is slightly different than would be solved by xvfb-run.

I'm wondering if --with-cairo presents a design flaw (maybe an abstraction
inversion https://en.wikipedia.org/wiki/Abstraction_inversion) wherein the
window system is taken for granted to be X and there is no way to change
it/use Cairo differently?

This has at least two consequences that I understand:
  - Most importantly, it makes --with-cairo silently incompatible with
--without-x.  If this is really intended, I think it should at least raise
a warning?
  - I think it also means, (as far as I know, but could well be wrong),
that there is not a way to use R where you rely solely Cairo?s rendering
abilities to replace the complexity of needing a specific window system
present? (This is my use case -- use cairo so R can be agnostic about a
window system).

Given that the earlier conversations made a fix sound rather trivial (use
cairo.h instead of cairo-xlib.h), I?m wondering if there is a path to
getting that implemented?

Thanks a lot,
-Stephen Marsh

On Wed, Jul 25, 2018 at 9:35 PM, Dirk Eddelbuettel <edd at debian.org> wrote:

>
> On 25 July 2018 at 21:04, Stephen Marsh wrote:
> | So the Homebrew community dropped support for --with-cairo which is a
> shame
> | because --without-x --with-cairo is an important combination for any
> | environment that might need to generate graphics without X11 (or related)
> | dependencies (macOS, headless linux servers).
>
> For headless use on Linux, just build as usual and run via `xvfb-run`. If
> you
> need to create cairo-based graphics, install one of the (at least two)
> cairo
> device packages from CRAN.
>
> Dirk
>
> --
> http://dirk.eddelbuettel.com | @eddelbuettel | edd at debian.org
>



-- 
stephenmarsh.co

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[Rd] Possible To Enable Building R With Cairo But Without X11 Dependencies?
Stephen Marsh