Add night theme switcher to color plugin

[hans-fritz-pommes]

I am trying to add a theme switcher to the color plugin - the color plugin is managing the night light, so it has the relevant settings and the functions for calculating the time and requirement checks to activate the night theme at the same time

[hans-fritz-pommes]

To Do:

• schedule_to in night_mode_recheck et night_theme_recheck et night_light_recheck
• find solution for test-ccm with the not anymore used schedule-mode-automatic setting-key
• rename the settings keys to night-mode-schedule-mode etc?
• find a solution for the multi-user-night-light problem

[anaximeno]

Looks a bit overkill here, besides, if the goal is a way to switch between night/day themes, there's already this nice applet: https://cinnamon-spices.linuxmint.com/applets/view/397

[hans-fritz-pommes]

Well, I didn't know this applet yet ¯\(ツ)/¯ - it's really nice.
Anyway: I still think it would be a nice feature. In the cinnamon-settings, there is the section "night-mode": It has one point to set: The night light. Don't you think it would be nice having the built-in-comfort of a night theme switcher - which you can activate under the light with one click?

[hans-fritz-pommes]

Can / should the keys night-light-schedule-from, night-light-schedule-to, night-light-last-coordinates and night-light-schedule-mode get renamed to "mode" instead of "light"?

[hans-fritz-pommes]

In the ccm-self-test-file, night-light-schedule was set using a non-existing night-mode-schedule-automatic-key (already before my idea). This should be updated to use the night-light-schedule-mode-enum, right? But then the enum values (in C) have to be defined somewhere else than in csd-night-mode.c, otherwise the ccm-file would have no access to them.

[hans-fritz-pommes]

In the meson.build-file, there are two sources = files (-sections. Why?

[hans-fritz-pommes]

By the way: I am encountering a problem with the night light:
(not because of my changes - also when using the default package 6.6.3+zena)
Two users, night light active for both, time based activation (auto/manual). User 2 logs in.
User 1 logs in, waits till the light is switched completely on (2700K), logs out
User 2 logs in: Night light is (most times, maybe not always) inactive

Getting org.cinnamon.SettingsDaemon.Color.Temperature via dbus: 2700K, NightLightActive: true
Should I open a new issue for this?

[hans-fritz-pommes]

The commit above fixes a bug which was in the code before I changed it. But I think this part of the code is never used - (yet?).

@mtwebster: For the existing multi-user problem described in the comment above: It seems like the problem occurs when ccm_set_gamma_for_all_devices (state); silently fails.
Is it smart to move the state->color_temperature = temperature; into the ccm_set_gamma... function? Or wait for some "SUCCESS!" return?