split off dependencies for optional installation (#546)

* add inheritance diagrams to all printers and exceptions
* split off printer implementations into separate files
* add wrapper that thros RuntimeError if not importable
* add dependency check for lp
* add dependency check for pyserial
* added check for usability
* import Win32Raw
* include WIn32Raw in documentation
* enable all extras on tox
* update github workflow

doc/user/installation.rst

@@ -12,7 +12,7 @@ so you can simply enter:
 
     ::
 
-        pip install python-escpos
+        pip install python-escpos[all]
 
 This should install all necessary dependencies. Apart from that
 python-escpos is for some versions also available as a Debian package.
@@ -21,6 +21,14 @@ always install from PyPi.
 If you use the ``--pre`` parameter for ``pip``, you will get the latest
 pre-release.
 
+The following installation options exist:
+
+ * `all`: install all packages available for this platform
+ * `usb`: install packages required for USB printers
+ * `serial`: install packages required for serial printers
+ * `win32`: install packages required for win32 printing (only Windows)
+ * `cups`: install packages required for CUPS printing
+
 Setup udev for USB-Printers
 ---------------------------
 1. Get the *Product ID* and *Vendor ID* from the lsusb command

doc/user/printers.rst

@@ -1,7 +1,7 @@
 Printers
 ========
 
-:Last Reviewed: 2023-08-10
+:Last Reviewed: 2023-08-23
 
 As of now there are 8 different types of printer implementations.
 
@@ -116,4 +116,8 @@ This driver uses a native WIN32 interface of Windows in order to print.
 Please refer to the code for documentation as this driver is currently
 not included in the documentation build.
 
-.. todo:: Include Win32Raw in documentation build
+.. autoclass:: escpos.printer.Win32Raw
+      :members:
+      :special-members:
+      :member-order: bysource
+      :noindex: