Move tiling exceptions to configuration file

[Tebro]

This moves out the hard coded tiling exceptions into a new separate config file under CosmicComp

[Drakulix]

Sorry, but we probably won't do this as one single config file.

Reason being that we want to ship the default rules and also be able to update them. So we likely want a new config file for rules added by users and default rules to be explicitly disabled.

Externalizing the default rules into a separate config file still makes sense, given we want to allow distros overwriting them.

I don't have the time to do a thorough review on your work now and will try to do so next week. In any case thanks for working on this!

[Tebro]

@Drakulix is there something I can do for this at this time?

[Drakulix]

@Drakulix is there something I can do for this at this time?

Yes, so looking at this further, what needs to be done to move this PR along is split the config file into two. One for the defaults and one for user-overrides (so either disabling existing rules from the defaults file or adding additional ones), because we want distros to provide the former and be able to update them without disrupting user configuration.

For this you can take inspiration from our shortcuts-config, which does the same (but is located in the cosmic-settings-daemon-crate: https://github.com/pop-os/cosmic-settings-daemon/blob/master/config/src/shortcuts/mod.rs#L53).

That also adds a new config namespace (com.system76.CosmicSettings.Shortcuts), we probably want the same for this, something like com.system76.CosmicSettings.WindowRules (anticipating, that we might have different rules in the future) and then tiling-exception-defaults and tiling-exception-custom for the files.

Given these should be configurable from cosmic-settings and cosmic-applet-tiling in the future, it might also make sense to move the config into the cosmic-settings-daemon repo (splitting this feature into two PRs).

The defaults file could still be installed by cosmic-comp, like the shortcuts file.
I don't have a problem with the whole config format (at least for the defaults file, the custom file would need to be slightly different to allow disabling existing rules), but I would prefer, if we didn't skip the whole config, if one regex fails to parse. I would appreciate it, if the deserialization code could skip over broken rules and just log a warning.

I understand, that this is a far bigger tasks, than you probably imagined opening this PR, so please don't see this as a demand. If you don't feel like working on this, we will eventually implement said feature. That said your effort and contribution is very appreciated.

[Tebro]

Thanks for the response. Will try to find some time to look into all of this. It would be nice to finish what was started.

[Tebro]

This is now updated, needs the PR in cosmic-settings-daemon to be merged first for the checks to pass.

[Drakulix]

This looks great!

I think there is just one thing missing, it doesn't appear to reload the config file at runtime. To do that you need to add some code to watch the config file, re-assemble the exceptions again and update the data in Shell.

You can see the code doing that for the shortcuts just below your new code in Config::load (config.rs).

[Tebro]

Got that working now.

[Drakulix]

Almost, just a small nitpick. Thanks for working on this :)

[Drakulix]

pop-os/cosmic-settings-daemon#50 merged, this needs a cargo update -p cosmic-settings-config

[Tebro]

Did the cargo update, some of the version moves in the diff looked confusing, such as libloading 0.8.5 -> 0.7.4. Pushed it up in case it is correct.

[Drakulix]

Thanks again for working on this!