[winswitch] fakeXinerama questions

[Antoine Martin]

Please always CC the list.

On 18/01/17 11:48, Lukas Haase wrote:
> Hi Antoine,
> 
>> (snip)
>>>> Ultimately what I could love is to let xpra IGNORE the first monitor (1366x768) and make it ONLY use the second two (1920x1200, 1920x1080). 
>>> This is not xpra's job: xpra forwards the windows to the client OS (ie:
>>> MS Windows 10 in this case), the client OS is in charge of placing the
>>> windows where it sees fit.
>> Thinking about this again, it shouldn't be too hard to implement an
>> override for this.
>> If you can create a ticket and follow up with some testing, we should be
>> able to do something.
> 
> That would be awesome, thank you!
> 
> But before, could you help me to understand what fakeXinerama does and how I see the results?
> 
> For simplicity, let's assume just a normal xpra client on Win 10 with 2 monitors 1366x768 and 1920x1200 and xpra server on Ubuntu (no ssh -X).
> 
> The application is gedit (supposedly using Xinerama according to ldd).
> 
> How would preloading fakeXinerama change on the client side compared to not using it at all?
The application (gedit in your example) may use Xinerama to get
information about the monitor geometry.

> How can I see the changes?
That depends entirely on what the application does with that information.

> As I said, I just don't see any differences on the client side, no matter which fakeXinerama settings I choose.
Then the application probably doesn't use the data we gave it.

The most common use-case for fakeXinerama is applications that maximize
or go fullscreen, as they may choose to only do so on one monitor.

> I even compiled with DEBUG so I see the messages that the client application is reading in the geometry ... but I don't see effects on the xpra client.
> 
> Also, from the original question: I think it should be more
> 2
> 1366 0 1920 1200
> 3286 0 1920 1080
> 
> ? Because the actual X area would be 5206x1200 with my 3 monitor setup. This configuration would split it into 2 monitors but have both of them offset by 1366 so there is no "monitor" and hence no windows should be places there.
No. Don't do that.
Your monitors should cover the whole display.

Cheers
Antoine

> 
> Best,
> Lukas
>