GSoC : Multiscreen management

[Aike J Sommer]

Am 02.04.2010 12:06, schrieb Will Stephenson:
> On Friday 02 April 2010 00:09:01 Björn Ruberg wrote:
>>> I have to check the difference between "Monitor", "Screen", "Display" and
>>> "Head" or are those actually the same thing ?
>>
>> "Monitor", "Display" and "Head" are probably the same - in Kephal they are
>> named as "Output". "Screen" ist actually something different. A screen can
>> have several outputs ordered left to right. If you have two monitors with
>> 1600x1200 pixels beside each other, you have a screen of 3200x1200 pixels
>> and two outputs in it. One at position 0x0 and one at 1600x0.
> 
> Aike, could you shed some light on this question?  Or Aaron, if you have the 
> overview of how Kephal works from mentoring Aike?
> 

Well.. A Screen is the logical area to which you can maximize a window
for example, or which has a panel at the bottom!
An output is the actual physical hardware / monitor...

So, for each connector that appears when calling xrandr there will be
one Output created, some enabled, some disabled... On my netbook those
are "VGA" and "LVDS", on my notebook something like "VGA", "LVDS" and
"TMDS-1" and on my HTPC "VGA" and "TV-1"!

How many Screens there are depends on your configuration:
- If you have only one enabled Output, you will have one Screen with the
same geometry
- If you have 2 or more overlapping Outputs, one Screen will be created
which spans all of those
- If you have multiple non-overlapping Outputs, one Screen will be
created per Output

One of the ideas was to be able to configure even non-overlapping
Outputs to be combined in one Screen, but that is not implemented...

Hope that helps!
:-)