implemented proper ascii fifo display for better local development

foobarpay.py

@@ -7,7 +7,7 @@ from sqlalchemy import create_engine
 from argparse import ArgumentParser
 
 from foobarpay.db import Database
-from foobarpay.display import Display
+from foobarpay.display import HIDrawDisplay, FifoDisplay
 from foobarpay.scanner import EvdevScanner, FifoScanner
 from foobarpay.logic import Logic
 from foobarpay.model.product import Product
@@ -22,7 +22,10 @@ class FooBarPay:
         logging.basicConfig(level=logging.DEBUG if cli_arguments.debug else logging.INFO)
 
         self.database = Database(cli_arguments.database, debug=cli_arguments.debug_sql)
-        self.display = Display(cli_arguments.display)
+        if cli_arguments.display_driver == "fifo":
+            self.display = FifoDisplay(cli_arguments.display)
+        else:
+            self.display = HIDrawDisplay(cli_arguments.display)
         if cli_arguments.scanner_driver == "fifo":
             self.scanner = FifoScanner(cli_arguments.scanner)
         else:
@@ -46,6 +49,7 @@ if __name__ == "__main__":
     parser.add_argument('-v', '--debug', dest='debug', action='store_true', help='general debug messages')
     parser.add_argument('--debug-sql', dest='debug_sql', action='store_true', help='sql debug messages')
     parser.add_argument('--display', dest='display', default=FooBarPay.DEFAULT_DISPLAY, help='specify display device')
+    parser.add_argument('--display-driver', dest='display_driver', choices=['hidraw', 'fifo'], default='hidraw', help='specify display driver')
     parser.add_argument('--scanner', dest='scanner', default=FooBarPay.DEFAULT_SCANNER, help='specify scanner device')
     parser.add_argument('--scanner-driver', dest='scanner_driver', choices=['evdev', 'fifo'], default='evdev', help='specify scanner driver')
     parser.add_argument('--db', dest='database', default=FooBarPay.DEFAULT_DATABASE, help='specify database file')

foobarpay/display.py

-class Display(object):
+class HIDrawDisplay(object):
     def __init__(self, path):
         self.path = path
         self.device = open(self.path, "wb")
@@ -35,3 +35,14 @@ class Display(object):
         message = b"\x02\x00" + bytes([len(command)]) + command + bytes(29 - len(command))
         self.device.write(message)
         self.device.flush()
+
+class FifoDisplay(HIDrawDisplay):
+    def set_position(self, pos_x, pos_y):
+        self.__send_command__(b"\n" + b" " * pos_x)
+
+    def clear(self):
+        self.__send_command__(b"\n")
+
+    def __send_command__(self, command):
+        self.device.write(bytes(command))
+        self.device.flush()

foobarpay/logic.py

@@ -55,7 +55,7 @@ class Logic(object):
                     self.transaction_start(customer_id)
                 else:
                     self.transaction_end()
-            if scanned_text.startswith(self.LOAD_PREFIX):
+            elif scanned_text.startswith(self.LOAD_PREFIX):
                 if self.state == self.State.Idle: # Product without active transaction
                     self.display.show_two_messages("Error", "Scan UID first")
                     sleep(3)