Internal and External monitor reversed about brightness

[LordAmit]

Hi Metro,
Thanks for the report. Really appreciate it.
Looks like you found a bug in xrandr documentation. :p It does not list brightness as an option in the xrandr --help output.

Now - about the core problem, I always assumed that the internal / primary monitor will be listed first in the xrandr output. Looks like it is not true for some cases, such as yours. Looking at xrandr output - I have seen two differences compared to mine.

1. Your xrandr listed external monitor as the first one.
2. The naming convention is not similar. Mine lists as LVDS1 whereas yours lists as LVDS-0

Either xrandr will have to make the output consistent across systems, or I will have to rename from internal/external to monitor 1/monitor 2 as a workaround.

Unfortunately, this is not an approach anyone will want to take, but - this is the only one I can think of right now. I will still check if there is any other way to sort the displays according to their internal and external nature.

[metropt]

can't find a place to tell xrandr developers about it :s

If all internal monitors are LVDSXXX maybe you can use it to define the internal monitor.

[LordAmit]

Oh, it is probably not a bug. The manual says --help gives a summary. Probably they didn't consider brightness for summary. Or it can be a bug after all.

Interesting idea, I will check if LVDS type is always the internal monitor - or something else can be considered as internal monitor as well. Thanks for it 😃

After a bit of Googling and Binging - I think the names should be primary/secondary. The name internal is too laptop-specific.

Looks like someone else also experienced something similar to yours.
http://superuser.com/questions/414646/xfce-cant-set-primary-monitor-in-xrandr

[metropt]

Hi,
The latest version still change my screen order. SimpleScreenRecord, a screen recording tool, give me the option to select which monitor I want to record and it label the screen in the right order. Maybe you can look at the code and see how they do it:
https://github.com/MaartenBaert/ssr

[archisman-panigrahi]

@metropt When you use a external display, you use it as primary,isn't it? Probably xrandr is programmed to work like this.
Please check if Brightness Controller is showing your internal display as primary when there are no other displays connected.

[LordAmit]

No, @apandada1 - it is up to user how they want to use the external display. For example, almost everyone will consider it secondary if the external display is actually a projector screen. For me, I always use the external monitor as secondary. The issue likes with xrandr itself, it automatically assigns the primary and secondary options as I explained in the links given above.

I think I have a solution that might appropriately solve this problem for users of Brightness Controller through the UI. It will take some time though, am working on a complete redesign of the whole brightness controller. 😉