Add support for slip/cheque dot matrix printers

AUTHORS

@@ -1,9 +1,11 @@
 Ahmed Tahri
 akeonly
+Alejandro Hernández
 Alexander Bougakov
 Alex Debiasio
 Asuki Kono
 belono
+B. Howell
 Brian
 Christoph Heuel
 Cody (Quantified Code Bot)
@@ -11,6 +13,7 @@ csoft2k
 Curtis // mashedkeyboard
 Davis Goglin
 Dean Rispin
+dependabot[bot]
 Dmytro Katyukha
 Gerard Marull-Paretas
 Hark
@@ -21,6 +24,7 @@ Kristi
 ldos
 Lucy Linder
 Manuel F Martinez
+Mathieu Poussin
 Maximilian Wagenbach
 Michael Billington
 Michael Elsdörfer

src/escpos/constants.py

@@ -77,6 +77,12 @@ LINE_DISPLAY_CLOSE = ESC + b"\x3d\x01"
 SHEET_SLIP_MODE = ESC + b"\x63\x30\x04"  # slip paper
 SHEET_ROLL_MODE = ESC + b"\x63\x30\x01"  # paper roll
 
+# Slip specific codes
+SLIP_EJECT = ESC + b"\x4b\xc0" # Eject the slip or cheque
+SLIP_SELECT = FS # Select the slip station as default station
+SLIP_SET_WAIT_TIME = ESC + b"\x1b\x66" # Set timeout waiting for a slip/cheque to be inserted
+SLIP_PRINT_AND_EJECT = b"\x0c" # Print the buffer and eject (after waiting for the paper to be inserted)
+
 # Text format
 # TODO: Acquire the "ESC/POS Application Programming Guide for Paper Roll
 #       Printers" and tidy up this stuff too.

src/escpos/escpos.py

@@ -30,6 +30,11 @@ from .constants import (
     QR_ECLEVEL_M,
     QR_ECLEVEL_H,
     QR_ECLEVEL_Q,
+    SHEET_ROLL_MODE,
+    SHEET_SLIP_MODE,
+    SLIP_PRINT_AND_EJECT,
+    SLIP_SELECT,
+    SLIP_EJECT
 )
 from .constants import (
     QR_MODEL_1,
@@ -1015,6 +1020,42 @@ class Escpos(object):
         if status[0] & RT_MASK_PAPER == RT_MASK_PAPER:
             return 2
 
+    """
+    Select where to print to
+
+    Print to the thermal printer by default (ROLL) or
+    print to the slip dot matrix printer if supported (SLIP)
+    """
+    def target(self, type='ROLL'):
+        if type.upper() == 'ROLL':
+            self._raw(SHEET_ROLL_MODE)
+        elif type.upper() == 'SLIP':
+            self._raw(SHEET_SLIP_MODE)
+        else:
+            raise ValueError("Unsupported target")
+
+    """
+    Eject the slip/cheque
+    """
+    def eject_slip(self):
+        self._raw(SLIP_EJECT)
+
+    """
+    Prints data from the buffer to the slip station and if the paper sensor is covered,
+    reverses the slip out the front of the printer far enough to be accessible to the operator.
+    The impact station opens the platen in all cases.
+    """
+    def print_and_eject_slip(self):
+        self._raw(SLIP_PRINT_AND_EJECT)
+
+    """
+    Selects the Slip Station for all functions.
+    The receipt station is the default setting after the printer is initialized or
+    the Clear Printer (0x10) command is received
+    """
+    def use_slip_only(self):
+        self._raw(SLIP_SELECT)
+
 
 class EscposIO(object):
     """ESC/POS Printer IO object