R devel - Apr 2008 - X11 window title setting in X11() Device (PR#11325)

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Content-Transfer-Encoding: quoted-printable

Hi,

I think I have found a very little bug in the new version of the X11()
device in R 2.7.0, more precisely in the devX11.c file.

The problem is that when you open a new window with X11(), the title
of the window (the WM_NAME property) is not immediately set. It seems
that the window is created, then it is displayed (mapped) with no
title, and then the title is set.

It is something absolutely invisible for the user, but it leads to
problem for me because I use a window manager that relies on window
titles to give them different attributes (I use it to make all my R
Graphics windows floating). And due to the fact that the title is set
after opening, my window manager rules don't apply anymore.

I found a quick and dirty workaround which set the title immediately
after the window opening if the =C2=ABtitle=C2=BB option in X11.options() is
set. You will find the patch for devX11.c attached to this mail, it is
just two lines moved before the call to X11_Open.

Surely there could be something much better, but I am quite new to C
and X11 programming...

Here is my sessionInfo() :

,----
| R version 2.7.0 (2008-04-22)=20
| i486-pc-linux-gnu=20
|=20
| locale:
|
LC_CTYPE=3Dfr_FR.UTF-8;LC_NUMERIC=3DC;LC_TIME=3Dfr_FR.UTF-8;LC_COLLATE=3Dfr_FR.UTF-8;LC_MONETARY=3DC;LC_MESSAGES=3Dfr_FR.UTF-8;LC_PAPER=3Dfr_FR.UTF-8;LC_NAME=3DC;LC_ADDRESS=3DC;LC_TELEPHONE=3DC;LC_MEASUREMENT=3Dfr_FR.UTF-8;LC_IDENTIFICATION=3DC
|=20
| attached base packages:
| [1] grDevices utils     datasets  graphics  stats     methods  
base=20=20=20=20=20
|=20
| other attached packages:
| [1] car_1.2-7
`----

Thanks for all your work !

Regards,

Julien=20


--=-=-Content-Type: text/x-diff
Content-Disposition: attachment; filename=devX11_patch.diff

--- devX11.c.orig	2008-04-28 16:22:46.000000000 +0200
+++ devX11.c	2008-04-28 16:22:57.000000000 +0200
@@ -2225,6 +2225,9 @@
 	else strcpy(xd->symbolfamily,fn);
     }
 
+    strncpy(xd->title, title, 100);
+    xd->title[100] = '\0';
+
     /*	Start the Device Driver and Hardcopy.  */
 
     if (!X11_Open(dd, xd, disp_name, width, height,
@@ -2238,8 +2241,6 @@
     xd->fill = 0xffffffff; /* this is needed to ensure that the
 			      first newpage does set whitecolor
 			      if par("bg") is not transparent */
-    strncpy(xd->title, title, 100);
-    xd->title[100] = '\0';
 
 #if BUG
     R_ProcessX11Events((void*) NULL);

--=-=-=--

Can you please give precise reproduction instructions -- you don't even 
tell us what the window manager is.

I'd be willing to consider a workaround, but only if I can reproduce the 
problem (which appears to be a false assumption elsewhere in your setup).

On Mon, 28 Apr 2008, julien.barnier at ens-lsh.fr wrote:
> --=-=-> Content-Type: text/plain; charset=utf-8
> Content-Transfer-Encoding: quoted-printable
>
> Hi,
>
> I think I have found a very little bug in the new version of the X11()
> device in R 2.7.0, more precisely in the devX11.c file.
>
> The problem is that when you open a new window with X11(), the title
> of the window (the WM_NAME property) is not immediately set. It seems
> that the window is created, then it is displayed (mapped) with no
> title, and then the title is set.
Which is perfectly valid in X11, so I don't see where the 'bug' is.

R changes the title to reflect the window state, do the supplied 'title'
is never actually used without decoration.  R 2.6.x put up one title and 
then immediately changed it, but that was undocumented and not safe to 
rely on (as you found).

> It is something absolutely invisible for the user, but it leads to
> problem for me because I use a window manager that relies on window
> titles to give them different attributes (I use it to make all my R
> Graphics windows floating). And due to the fact that the title is set
> after opening, my window manager rules don't apply anymore.
>
> I found a quick and dirty workaround which set the title immediately
> after the window opening if the =C2=ABtitle=C2=BB option in X11.options()
is
> set. You will find the patch for devX11.c attached to this mail, it is
> just two lines moved before the call to X11_Open.
>
> Surely there could be something much better, but I am quite new to C
> and X11 programming...
>
> Here is my sessionInfo() :
>
> ,----
> | R version 2.7.0 (2008-04-22)=20
> | i486-pc-linux-gnu=20
> |=20
> | locale:
> |
LC_CTYPE=3Dfr_FR.UTF-8;LC_NUMERIC=3DC;LC_TIME=3Dfr_FR.UTF-8;LC_COLLATE=3D>
fr_FR.UTF-8;LC_MONETARY=3DC;LC_MESSAGES=3Dfr_FR.UTF-8;LC_PAPER=3Dfr_FR.UTF->
8;LC_NAME=3DC;LC_ADDRESS=3DC;LC_TELEPHONE=3DC;LC_MEASUREMENT=3Dfr_FR.UTF-8;>
LC_IDENTIFICATION=3DC
> |=20
> | attached base packages:
> | [1] grDevices utils     datasets  graphics  stats     methods  
base=20> =20=20=20=20
> |=20
> | other attached packages:
> | [1] car_1.2-7
> `----
>
> Thanks for all your work !
>
> Regards,
>
> Julien=20
>
>
> --=-=-> Content-Type: text/x-diff
> Content-Disposition: attachment; filename=devX11_patch.diff
>
> --- devX11.c.orig	2008-04-28 16:22:46.000000000 +0200
> +++ devX11.c	2008-04-28 16:22:57.000000000 +0200
> @@ -2225,6 +2225,9 @@
> 	else strcpy(xd->symbolfamily,fn);
>     }
>
> +    strncpy(xd->title, title, 100);
> +    xd->title[100] = '\0';
> +
>     /*	Start the Device Driver and Hardcopy.  */
>
>     if (!X11_Open(dd, xd, disp_name, width, height,
> @@ -2238,8 +2241,6 @@
>     xd->fill = 0xffffffff; /* this is needed to ensure that the
> 			      first newpage does set whitecolor
> 			      if par("bg") is not transparent */
> -    strncpy(xd->title, title, 100);
> -    xd->title[100] = '\0';
>
> #if BUG
>     R_ProcessX11Events((void*) NULL);
>
> --=-=-=--
>
> ______________________________________________
> R-devel at r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-devel
>
-- 
Brian D. Ripley,                  ripley at stats.ox.ac.uk
Professor of Applied Statistics,  http://www.stats.ox.ac.uk/~ripley/
University of Oxford,             Tel:  +44 1865 272861 (self)
1 South Parks Road,                     +44 1865 272866 (PA)
Oxford OX1 3TG, UK                Fax:  +44 1865 272595

Hi,
> Can you please give precise reproduction instructions -- you don't
> even tell us what the window manager is.
> I'd be willing to consider a workaround, but only if I can reproduce
> the problem (which appears to be a false assumption elsewhere in your
> setup).
Yes, sorry, it is one of my first bug report so please forgive me for
being incomplete.

The window manager I use is dwm, which can be found at :

http://www.suckless.org/wiki/dwm

It is a lightweight tiled window manager with configuration by
compilation. You can change settings by modifying the config.h file
and recompiling dwm.c. The setting which cause problem in my config.h
is the following :

Rule rules[] =3D {
        /* class        instance        title           tags ref       
isfloating */
        { NULL,         NULL,           "R Graphics",   NULL,       
True},

which makes every window whose title match the =C2=ABR Graphics=C2=BB substring
to be considered as a floating window.

If you use dwm with this configuration rule, launch R and open a
graphics window, it will not be set as floating but will remain tiled
(which is the default).

The problem is that dwm applies the rule given above as soon as the
window is mapped. But in R 2.7.0, when the window is mapped she
doesn't have any title (it is assigned later), so the rule doesn't
apply because the window is considered having no instance name, no
class name (the WM_CLASS attribute) and no title.
> Which is perfectly valid in X11, so I don't see where the 'bug'
is.
>
> R changes the title to reflect the window state, do the supplied
> title' is never actually used without decoration.  R 2.6.x put up one
> title and then immediately changed it, but that was undocumented and
> not safe to rely on (as you found).
You're perfectly right by saying that it is not a bug per se, it is
just a small change which shouldn't affect the vast majority of users
but those who rely on windows attributes to manage them. But maybe I
am the only one in that case...

Another workaround could be to give a class or instance name specific
to the graphics windows.

Thanks for your answer and sorry for the incomplete bug report.

Regards,
--=20
Julien Barnier
Groupe de Recherche sur la Socialisation
ENS Lettres et Sciences humaines, Lyon
T=C3=A9l : 04 37 37 62 92