[Openicc] GSoC 2013 preparations

[Kai-Uwe Behrmann]

Am 19.03.2013 09:56, schrieb Richard Hughes:
> On 19 March 2013 08:39, Kai-Uwe Behrmann <ku.b at gmx.de> wrote:
>> Can you elaborate on this problem. I do not see here that CMS configurations
>> are frequently written. If they need persitent frequently rewriting, then
>> there is something wrong with the underlying architacture. Just to be clear,
>> we talk here about device configurations and some few settings.
>
> We have three moving pieces that could, in theory read and write the
> same settings:
>
> * ArgyllCMS
> * Oyranos
> * colord
>
> If I understand correctly, Oyranos and ArgyllCMS run in the user
> session context only, and colord runs in the system context only.

As daemon yes. But they can write system wide settings. E.g. Argyll has
/etc/xdg/color.jcnf for that.

> * If Oyranos writes to the user ~/.config/color/settings/ how is
> colord supposed to know that settings have changed?

There are no file I/O API's for that? When I copy files with UNIX cp, 
they are instandly seen by GUI file browsers.

> * How is argyllcms supposed to set a specific profile to be used on
> the login screen if it can't write to /usr or /var?

Why should a CMS not write to that, provided it obtains the needed 
privilegs?

> * If colord sets a new system-wide profile to be used by all users,
> how is it supposed to remove or nullify the entry in ~/.config that
> will override it?

A system level configuration will be fallen back to, if no sufficient 
user configuration is provided. That is how most UNIX systems work. E.g. 
most people would not like a admin to override a personal selected 
desktop theme. A preference of a admin over a user session or workspace 
is completely contrary to desktops concepts like in KDE.

Therefore I suggest a slighty different approach:
A CMS can start searching for a non automatic profile for a device in 
the user path, then in the system path. If nothing was found it searches 
for a automatic profile in first user paths then system ones and if that 
gives no success it falls back to a automatic generated profile or 
likely sRGB.

kind regards
Kai-Uwe