X11 device windows are spawned with empty WM_NAME property

On Jun 17, 2011, at 01:53 , Drew Frank wrote:

Hello,

I've noticed that X11 device windows (the ones that pop up when I plot
something on Linux) aren't assigned any WM_NAME property until after they've
been spawned.  This causes problems for users of tiling window managers, who
may wish to use the WM_NAME property to decide whether to float or tile the
window.

If I create a plot and then examine the window properties with xprop, I see
something like the following: WM_NAME(STRING) = "R Graphics: Device 2
(ACTIVE)".  However, by instructing my window manager (xmonad) to float all
windows with a matching name, I can tell that when the window was created
its WM_NAME property was empty.

Is this behavior intended?  Would be it be reasonable to instead create
windows with a generic name like "R Graphics" prior to updating them with
the device number and active/inactive status?

I'm not familiar with the R code base, but I found that creating a plot
results in a call to the function in_do_X11 in the file
src/modules/X11/devX11.c.  In that function (around like 2869) there is code

to parse out the window title from the SEXP args parameter, and it always
seems to parse out an empty string.  If I manually assign title="R Graphics"
at that point, I am able to successfully float R plot windows based on their
WM_NAME. (line numbers based on SVN revision 56131)

Is this actually an issue that needs fixing?  Should I create a bug report
for this?

A well-tested patch might be considered, but beware of the demons...

Notice that you can actually set the title via X11(title="Foo's 
bar"). If you do that, it won't display the device number. So (a) 
you wouldn't want to destroy that feature, and (b) how does the code 
that inserts the "Device 2" bit know that it can do so? By checking 
for an empty title? (Yup).

I notice that the initial title string could contain formatting 
characters, so possibly, what you really want to do is to default it 
to "R Graphics: Device %d"). Something of the sort is already 
happening with the quartz() device.

Thanks,
Drew

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Peter Dalgaard
Center for Statistics, Copenhagen Business School
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