added support for printing simple labels

labeler/infra/e550w_printer/printer.py

@@ -1,10 +1,14 @@
+import io
+import logging
 from math import inf
 
+from brother_ql import BrotherQLRaster, create_label
+from brother_ql.backends import guess_backend, backend_factory
 from pysnmp.entity.engine import SnmpEngine
 from pysnmp.hlapi import getCmd, CommunityData, UdpTransportTarget, ContextData
 from pysnmp.smi.rfc1902 import ObjectType, ObjectIdentity
 
-from labeler.domain.objects import MediaDefinition, Dimension
+from labeler.domain.objects import MediaDefinition, Dimension, Image
 from labeler.infra.e550w_printer.media_definitions import (
     media_width,
     tape_color,
@@ -16,6 +20,12 @@ from labeler.infra.e550w_printer.media_definitions import (
     TYPE_BYTE,
 )
 from labeler.interfaces import Printer
+from PIL import Image as PILImage
+
+PRINTABLE_WIDTH = {
+    12: Dimension.from_points(150, 360),
+    24: Dimension.from_points(320, 360),
+}
 
 
 class E550W(Printer):
@@ -26,6 +36,45 @@ class E550W(Printer):
     def get_installed_media(self) -> MediaDefinition:
         return self.__get_printer_status()
 
+    def print_label(self, label: Image):
+        im = PILImage.open(io.BytesIO(label.bytes))
+
+        qlr = BrotherQLRaster("PT-E550W")
+        create_label(
+            qlr,
+            im,
+            self.__media_width_to_type(label.height),
+            red=False,
+            threshold=70,
+            cut=True,
+            rotate=270,
+            compress=True,
+            dpi_600=True,
+            hq=True,
+        )
+
+        try:
+            try:
+                selected_backend = guess_backend(f"tcp://{self.ip_address}:9100")
+            except ValueError:
+                logging.error(
+                    "Couln't guess the backend to use from the printer string descriptor"
+                )
+            BACKEND_CLASS = backend_factory(selected_backend)["backend_class"]
+            be = BACKEND_CLASS(f"tcp://{self.ip_address}:9100")
+            be.write(qlr.data)
+            be.dispose()
+            del be
+        except Exception as e:
+            logging.exception("Exception happened: %s", e)
+
+    def __media_width_to_type(self, height: int):
+        metric_width = Dimension.from_points(height, 360)
+        if metric_width == Dimension.from_points(150, 360):
+            return "pt512"
+        else:
+            raise ValueError(f"Unsupported media width: {metric_width}")
+
     def __get_printer_status(self):
         raw_snmp_data = self.__get_snmp_status().asNumbers()
         width = media_width(raw_snmp_data[WIDTH_BYTE])
@@ -36,9 +85,9 @@ class E550W(Printer):
         return MediaDefinition(
             width=Dimension(mm=width),
             length=Dimension(mm=inf),
-            minimal_margin_vertical=Dimension(mm=1),
-            minimal_margin_horizontal=Dimension(mm=2),
-            dpi=600,
+            minimal_margin_vertical=(Dimension(mm=width) - PRINTABLE_WIDTH[width]) / 2,
+            minimal_margin_horizontal=Dimension(mm=1),
+            dpi=360,
             description=f"{tape_type} - {width}mm, {media_text_color} on {media_tape_color} background",
         )