xppen: init package with nixos module

[nasrally]

Description of changes

Added XPPen PenTablet package and a program.xppen module for it

Things done

I've initially made this for my friend who asked me if I could port XPPen on NixOS, I did, so now I'd like to add it to nixpkgs.
I have a few concerns however, the primary is that I'm not quite sure about the licensing of XPPen, there is practically no information I could find and the only way to contact XPPen is through mail which, if I'm completely honest, I just don't want to do.

I also don't own an XPPen tablet and don't really know much about them unlike my friend but he's not quite there yet in terms of being able to package it himself.

Do my changes relate to #213263 and the pentablet-driver package???

Also this is my very first time trying to add a package/module to nixpkgs so please tell me if I'm doing things wrong, I tried my best but I suppose there are things that can be improved.

• Built on platform(s)
  • x86_64-linux
  • aarch64-linux
  • x86_64-darwin
  • aarch64-darwin
• For non-Linux: Is sandboxing enabled in nix.conf? (See Nix manual)
  • sandbox = relaxed
  • sandbox = true
• Tested, as applicable:
  • NixOS test(s) (look inside nixos/tests)
  • and/or package tests
  • or, for functions and "core" functionality, tests in lib/tests or pkgs/test
  • made sure NixOS tests are linked to the relevant packages
• Tested compilation of all packages that depend on this change using nix-shell -p nixpkgs-review --run "nixpkgs-review rev HEAD". Note: all changes have to be committed, also see nixpkgs-review usage
• Tested basic functionality of all binary files (usually in ./result/bin/)
• 24.05 Release Notes (or backporting 23.05 and 23.11 Release notes)
  • (Package updates) Added a release notes entry if the change is major or breaking
  • (Module updates) Added a release notes entry if the change is significant
  • (Module addition) Added a release notes entry if adding a new NixOS module
• Fits CONTRIBUTING.md.

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[nasrally]

Also please anyone with an actual XPPen tablet tell me if what I've made actually works, I have no means of testing it myself, I just know that the app is running and the udev rules are applied 🙏🙏

[nasrally]

I tested the module, looks like I didn't break anything

[nasrally]

Oh and also one other question. Is it maybe possible to backport this change to 23.11?

[h7x4]

Yes, I think so, but I'm a bit unsure about how to deal with backporting release notes. I'll ask around to see if I can find some answers.

In the meanwhile, could you squash your changes into the first three commits? If you're unsure about how to do it, feel free to ask. I might be a good idea to mark the PR as draft before push, because a rebase gone wrong will ping a ton of people.

[nasrally]

Didn't really want to bother remembering how to rebase properly so just git reset --soft'ed and recreated the commits. Hope it's good enough

[nasrally]

Why is it suddenly unable to find libusb?

[h7x4]

Might've been after you moved it to pkgs/by-name. libusb1 is the correct one.

[nasrally]

I borked it, okay, will never make changes on the phone again, must've missed something important .-.

[nasrally]

h7x4, thank you so much for helping!

[nasrally]

Is this a good-enough service? I'm not familiar with how people usually do it in nixpkgs, I've found a few examples with grep and followed them (nginx and nifi)
Seems to be working for me

[nasrally]

However it seems like this service runs every time I nixos-rebuild my system with it even if nothing was changed :/ Is this normal? Do I need to add some nixos-specific conditions?

[MinerSebas]

The missing piece should just be adding restartTriggers = [ cfg.package ] to the service.

[eclairevoyant]

Thank you for your work so far! Some feedback below.

[eclairevoyant]

This service seems like something that might be better achieved with systemd-tmpfiles

[nasrally]

Unfortunately I don't think it can, those files are installed in /var because it's kind of a hack and are not temporary, those are user configuration files:///

[eclairevoyant]

things created via systemd-tmpfiles are not necessarily temporary, despite the name.

[nasrally]

Or can tmpfiles be used to store files persistently? My problem is that I don't think I'd want those user-changed configs to be removed even is the module is disabled. If I could patch this app to read configs from, say, $XDG_CONFIG_HOME I would, but me no smart enough to patch binaries to this degree. /var is better than the default /usr but yes it is incredible that they even fathomed to make /usr/lib a user-writable configuration directory :)))
So yeah, don't think tmpfiles is good, these files are by no means temporary

[nasrally]

things created via systemd-tmpfiles are not necessarily temporary, despite the name.

So what would the added benefit be then? Can it copy a set of given files instead of this little scripty thingy?

[nasrally]

I'm just not familiar with systemd-tmpfiles that's why I'm asking:)

stale review

[damiankorcz]

Hey,
I have an XP-Pen Deco LW. This model works wired and wireless (Bluetooth - comes with a receiver) so I can test both scenarios. By default in KDE 6, it get detected and moves the cursor (wired or wireless). I would like to help get this PR updated and merged. I've tried to build it and it appears to build fine although when running the PenTablet executable I get the following:

[damian@nixos-desktop:~/Git/nixpkgs/result/bin]$ ./PenTablet
QFont::fromString: Invalid description 'Noto Sans,10,-1,5,400,0,0,0,0,0,0,0,0,0,0,1'
QLocale::English
QMetaObject::connectSlotsByName: No matching signal for on_horizontalSlider_tablet_light_valueChanged(int)
QObject::connect: Incompatible sender/receiver arguments
        QDesktopWidget::primaryScreenChanged() --> MainWindow::onDeskScreenChanged(int)
QLayout: Attempting to add QLayout "" to MainWindow "MainWindow", which already has a layout
Function  EnumDisplay nScreenCount: 4
Device.AllScreen "(0,0,4640,2880)"
Device.Screen 1 : "1(1440,1440,2560,1440)"
Device.Screen 2 : "2(0,320,1440,2560)"
Device.Screen 3 : "3(1440,0,2560,1440)"
Device.Screen 4 : "4(4000,2400,640,480)"
-------type: 1
hid_open_path Failed!
Cannot mix incompatible Qt library (5.15.14) with this library (5.15.12)
Aborted (core dumped)

Let me know what you want me to try further. Also, it appears the version is still 3.4.9 but they add a suffix with YYMMDD e.g. currently it's on XPPenLinux3.4.9-240607. So might need to amend how the versions are defined.

[nasrally]

Hey @damiankorcz, I have completely forgotten about this PR. Unfortunately I don't have much time to fix and update it myself, but I think you can suggest changes and fixes, I'll add them. I can still push some effort into getting this PR merged :)

[gepbird]

A few months ago drivers with major version 4 got released. However some tablets are not compatible with v4, so we should definitely keep the current v3 driver.

Based on the previous v3 deco and g430 drivers, I packaged a working v4 driver in #347984 (tested by @HangedFool, I don't have a hardware for it), however it is not as polished as this PR but should be a decent starting point.

It would be nice to add the v4 package in this PR, but I totally understand if you don't have the capacity for it, it can be done later. At least we should make the v3 package in this PR future proof by renaming it to xppen_3 to avoid making aliases in the future that might confuse/annoy users.

[gepbird]

Cannot mix incompatible Qt library (5.15.14) with this library (5.15.12)

@damiankorcz This is most likely not an issue with the the xppen package in this PR, but rather with Qt packages on NixOS in general.

Personally I don't have this issue and the GUI opens, but this is what I found after doing some research:

• according to QT version mismatch error #37864 (comment), the issue should be fixed by using wrapQtAppsHook, but it's already done with xppen so it's not the case
• (temporarily) uninstalling Qt apps and removing them from the nix store worked for some people, see https://discourse.nixos.org/t/migrating-from-plasma5-to-plasma6/40514/3
• people strace'd the problematic Qt apps to find out why is it trying to use different Qt versions Mixing incompatible Qt library (version 0x50902) with this library (version 0x50901) #30551 (comment)

I haven't found a clear answer, but if you really want to test this PR you could try temporarily uninstalling your qt apps (also delete them with nix-collect-garbage) or updating your system to unstable (I assume you're on nixos-24.05 from the 5.15.12 Qt version). Or at this point setting up a nixos-unstable vm seems to be easier.

[gepbird]

Hi, I don't want to be intrusive, but if you don't have time to work on this I'd be happy to take it over if it's fine with you (of course I'd credit you for all the work you've done over the past months :) ).

Is there anything else blocking this PR?

[gepbird]

See #285660 (comment) for explanation

Suggested change

	pname = "xppen";
	pname = "xppen_3";

[gepbird]

Suggested change

	package = lib.mkPackageOption pkgs "xppen" { };
	package = lib.mkPackageOption pkgs "xppen_3" { };