request: a cheap way to check if redshift is active

[klaernie]

Is there an easy way to find out, if redshift is active on a given display (active as in 'might decide to drive the color temperature')?

The use case would that an application like autorandr can easily detect, if redshift is active for the current display, without scanning all processes on the machine for one named redshift, and then checking if the environment of a maybe found process has the same display as the one it currently tries to save the xrandr config for. My suggestion for a possible implementation would be an X11 property set on the root window.

To understand why I am asking for this consider this case:

1. I start redshift and it becomes night, so it adjusts the temperature to a warmer color.
2. I save my default configuration with autorandr
3. autorandr saves the current gamma values
4. I wait until the next daylight
5. I reboot my machine, autorandr starts and applies it's saved gamma values, which now means, that I get the same color temperature I had when I saved the config.

I already asked at phillipberndt/autorandr#236 for a check for skewed gamma values before saving, but of cause an implementation is harder when checking for a running redshift is hard.

Thanks, Andre

[dandv]

That's a good request also for the UI. I often wonder if Redshift has kicked in, so I go and uncheck "Enable", to see if the screen changed tint.

[allanlaal]

critical for people needing accurate colors during work