Ideal screen rotation

[Nicola Mfb]

On Sat, Nov 7, 2009 at 1:55 PM, Carsten Haitzler <raster at rasterman.com> wrote:
[...]
> yes. see above. apps are doing it all the time. it's about the most standard
> way to provide information about your window, from title to minimum and maximum
> size to aspect ratios and more. rotation preferences are just yet more
> properties like this. if its a "property" of the window - put it as a property
> of the window. use the mechanism created for precisely this kind of thing. dbus
> is not that mechanism.
[...]
> if an app has rotation preferences, it should set them. if it has none - it
> gets whatever the screen has right now - or whatever the wm chooses to
> implement as policy. yes - you modify apps to have them indicate their
> preferences. otherwise they are deemed to "not care" which is the case now, for
> example. you modify the apps - thats the right way to do it. you don't
> post-mortem find a way to hack things in. :)
>
>> Also do you know if there's already a well-known window property for
>> preferred rotation, or would we be inventing a new one?
>
> you'd be inventing it.

I agree that window properties is the right way to implement that, but
we need a way to get rotation preferences now, while that may be
proposed and discussed as a standard for the future.

So a couple of questions:

* is it possible/safe/correct to set a window properties of a
window/xclient by an external app (e.g. a launcher)?
* supposing the above is possible, we may add a custom configuration
entry in .desktop files and delegate the launcher to set window
properties
* if that is not possible the wm or an ewmh app helper (the launcher
itself?) may get the active current window and perform the screen
rotation as needed

In every case and going a bit ot, is anyway possibile having a generic
Window ID to retrieve the .desktop file originating the owning app?
I'm just guessing to retrieve the pid from window properties, retrieve
the executable (like /proc/pid/exe) and back search in the .desktop
file definitions.
But this seems weight as the Exec in .desktop files may be a relative
path, a link etc, for sure there is a better way, may you explain
them?

Thanks and Regards

     Nicola