udev-rules: use the uaccess method instead of custom group to setup perms

55-spotlight.rules.in

@@ -1,22 +1,11 @@
 # Set up permissions for non root users to open the Logitech Spotlight USB Receiver
 # Enables the Projecteur application to access the device.
 
-# Copy this file to /etc/udev/rules.d/55-spotlight.rules and replace '@DEVICE_USER_GROUP@'
-# with a group your user is a member in. 
-#
-# Existing groups like 'plugdev' and 'dialout' can be used, but the `install` target
-# uses a group called 'spotlight-device' by default. 
-# Linux packages created with the 'dist-package' target will create this group if not
-# present during installation.
-#
-# Run `sudo udevadm control --reload-rules` and `sudo udevadm trigger`
-# to load rules without rebooting.
-
-# Note that for kernels before 2.6.24, you will need to substitute "usb" with "usb_device".
+# Copy this file to /etc/udev/rules.d/55-spotlight.rules
 
 # Rule for USB Receiver
-SUBSYSTEMS=="usb", ATTRS{idVendor}=="046d", ATTRS{idProduct}=="c53e", MODE="660", GROUP="@DEVICE_USER_GROUP@", ENV{USB_HUB_TYPE}="046d:c53e"
+SUBSYSTEMS=="usb", ATTRS{idVendor}=="046d", ATTRS{idProduct}=="c53e", MODE="0660", TAG+="uaccess"
 
 # Rule when connected via Bluetooth
 # Updated rule, thanks to Torsten Maehne (https://github.com/maehne)
-SUBSYSTEMS=="input", ATTRS{name}=="SPOTLIGHT*", MODE="660", GROUP="@DEVICE_USER_GROUP@"
+SUBSYSTEMS=="input", ATTRS{name}=="SPOTLIGHT*", MODE="0660", TAG+="uaccess"

CMakeLists.txt

@@ -87,7 +87,6 @@ set (CMAKE_INSTALL_UDEVRULESDIR ${UDEVDIR}/rules.d CACHE PATH "Where to install
 mark_as_advanced(CMAKE_INSTALL_UDEVRULESDIR)
 
 # Configure and install files
-set(DEVICE_USER_GROUP spotlight-device)
 set(OUTDIR "${CMAKE_CURRENT_BINARY_DIR}")
 set(TMPLDIR "${CMAKE_CURRENT_SOURCE_DIR}/cmake/templates")
 

README.md

@@ -28,8 +28,8 @@ So here it is: a Linux application for the Logitech Spotlight.
 ## Supported Environments
 
 The application was tested on Ubuntu 18.04 (GNOME) and OpenSuse 42.3 and 15 (GNOME)
-but should work on almost any Linux/X11 Desktop. In case you are building the 
-application youself, make sure you have the correct udev rules installed 
+but should work on almost any Linux/X11 Desktop. In case you are building the
+application youself, make sure you have the correct udev rules installed
 (see Installation Pre-requisites).
 
 ## How it works
@@ -99,10 +99,10 @@ The input devices detected from the Spotlight device must be readable to the
 user running the application. To make this easier there is a udev rule template
 file in this repository: `55-spotlight.rules.in`
 
-* Copy that file to `/etc/udev/rules.d/55-spotlight.rules` and replace the
-  '@DEVICE_USER_GROUP@' in the file with a group your user is a member in
-* Run `sudo udevadm control --reload-rules` and `sudo udevadm trigger` to load
-  the rules without a reboot.
+* Copy that file to `/etc/udev/rules.d/55-spotlight.rules`
+* Most recent systems (using systemd) will automatically pick up the rule.
+  If not, run `sudo udevadm control --reload-rules` and `sudo udevadm trigger`
+  to load the rules without a reboot.
 * After that the two input devices from the Logitech USB Receiver in /dev/input
   should have the group you used, i.e. the group you configured in the rules file.
 * When building against the Qt version that comes with your distribution's packages
@@ -145,7 +145,7 @@ is not showing, commands can be send to the application to bring up the preferen
 dialog, to test the spotlight or quit the application.
 See [Command Line Interface](#command-line-interface).
 
-On some distributions that have a GNOME Desktop by default there is no system tray 
+On some distributions that have a GNOME Desktop by default there is no system tray
 extensions installed (_Fedora_ for example). You can install the "TopIcons Plus" GNOME
 extension to have a system tray that can show the Projecteur tray icon (and also from other
 applications like Dropbox or Skype)
@@ -169,9 +169,9 @@ If the device shows as not connected, there are some things you can do:
   `cat /proc/bus/input/devices | grep -A 3 "Vendor=046d"` \
   This should show one or multiple spotlight devices (among other Logitech devices)
 * Make sure the detected devices have the correct user/group asssigned. \
-  Run `ls -al /dev/input/event* | grep spotlight` 
+  Run `ls -al /dev/input/event* | grep spotlight`
   (or replace `spotlight` by a string that matches the group you put into the
-   udev rule file in case you edited it yourself). 
+   udev rule file in case you edited it yourself).
 * Make sure you don't have conflicting udev rules installed, e.g. first you installed
   the udev rule yourself and later you used the automatically built Linux packages to
   install _Projecteur_.

cmake/templates/preinst.in

@@ -1,4 +1 @@
-# Create `@DEVICE_USER_GROUP@` group if it does not exist (used in udev rules).
-if ! getent group @DEVICE_USER_GROUP@ >/dev/null; then
-    groupadd --system --force @DEVICE_USER_GROUP@
-fi
+#