module(widgets): mass refactor, add system tray and battery

[pluiedev]

Fixes #126

Here's a list of changes:

• Most of the code that generates the JS required for adding and configuring the widgets are now moved to modules/widgets/lib.nix. Since system trays are also technically containments, and configuring things there is very similar to configuring a panel, it's worth refactoring it into code that can be shared for both.

• Every panel is now in its own scope, in order to avoid name collisions. As a direct consequence of that, all vars are replaced by consts, as there's now no need for redeclaring variables. Besides, var is a code smell anyways in modern JS due to its unpredictable scoping rules, and it's best to avoid it in new code.

• Config fields in the same group of the same widget will now share the w.currentConfigGroup and w variable assignments. Essentially, instead of this:

  var w = panelWidgets["org.kde.plasma.systemmonitor"];
  w.currentConfigGroup = ["Appearance"];
  w.writeConfig("title", "CPU Usage");
  
  var w = panelWidgets["org.kde.plasma.systemmonitor"];
  w.currentConfigGroup = ["Sensors"];
  w.writeConfig("highPrioritySensorIds", '["cpu/all/usage"]');
  
  var w = panelWidgets["org.kde.plasma.systemmonitor"];
  w.currentConfigGroup = ["Sensors"];
  w.writeConfig("lowPrioritySensorIds", '["cpu/all/temperature"]');
  
  var w = panelWidgets["org.kde.plasma.systemmonitor"];
  w.currentConfigGroup = ["Sensors"];
  w.writeConfig("totalSensors", '["cpu/all/usage"]');

  We now generate:

  const w = panelWidgets["org.kde.plasma.systemmonitor"];
  w.currentConfigGroup = ["Appearance"];
  w.writeConfig("title", "CPU Usage");
  
  w.currentConfigGroup = ["Sensors"];
  w.writeConfig("highPrioritySensorIds", "[\"cpu/all/usage\""]);
  w.writeConfig("lowPrioritySensorIds", "[\"cpu/all/temperature\""]);
  w.writeConfig("totalSensors", "[\"cpu/all/usage\"]");

  This massively cuts down generated code, and is much cleaner in general.

• Every setting on every widget is now nullable. Setting anything to null basically makes it unset, which allows us to eliminate setting a default on the Nix side, so that upstream default changes won't affect us.

• An extraConfig field has been added for raw widgets, that takes a lambda/anonymous function that accepts one argument — the widget to be configured. I figure this allows more room for the user to name the widget whatever they want, and not rely on hardcoded variable names.

  This is required to make system trays work, because configuring them is... quite peculiar, to say the least.

• I've added a link to the config/main.xml file that defines each widget's config options, which is a much more reliable source than KDE docs.

• The widget system now makes use of native module system features (such as the apply field for mkOption), in order to make converters less of an eyesore, make Nix report better errors, and make the system more robust against erroneous user input in general.

• And of course, you can now customize system trays to your liking, without knowing what eldritch horror lies beneath to make it work.

• Also, battery indicators!

[pluiedev]

I also realized that users would be able to do something patently stupid like:

{
  widgets = [
    {
      systemTray.items.configs = {
        systemTray.items.configs = {
          systemTray.items.configs = {
            battery.showPercentage = true;
          };
        };
      };
    }
  ];
}

Should you do this? No. Should you be able to do this? Yes.

[magnouvean]

Nice. It's quite a big pr, but hopefully I can test it this weekend.

[magnouvean]

Works great as usual :). Will merge when checks are done. Thanks a lot once again!

[lgoette]

Hey, thanks for the contribution. Works great :D
Is it possible to set popupHeight and popupWidth of the systemtray? I did not find options for these settings.

[pluiedev]

Hey, thanks for the contribution. Works great :D Is it possible to set popupHeight and popupWidth of the systemtray? I did not find options for these settings.

Give it a try - it might not work 'cause I didn't set the freeformType, though

[lgoette]

I am not that familiar with how this works, sorry. But while iconSpacing etc is set in the [Containments][systrayID][General] location, popupHeight is set in the [Containments][systrayID] location. Is there an option to access this part of the config?