LabelPrinter functionality

barcode_helpers.py

@@ -0,0 +1,62 @@
+from PIL import ImageFont
+from barcode.writer import ImageWriter, mm2px
+from brother_ql.devicedependent import label_type_specs
+
+
+def px2mm(px, dpi=300):
+    return (25.4 * px)/dpi
+
+
+class BrotherLabelWriter(ImageWriter):
+    def __init__(self, typ='62', max_height=350, rot=0, text=None):
+        super().__init__()
+        assert typ in label_type_specs
+        if (rot//90) % 2 == 1:
+            self._h, self._w = label_type_specs[typ]['dots_printable']
+            if self._w == 0 or self._w > max_height:
+                self._w = max_height
+        if (rot//90) % 2 == 0:
+            self._w, self._h = label_type_specs[typ]['dots_printable']
+            if self._h == 0 or self._h > max_height:
+                self._h = max_height
+        self._xo = 0.0
+        self._yo = 0.0
+        self._title = text
+
+    def _init(self, code):
+        self.text = None
+        super()._init(code)
+
+    def calculate_size(self, modules_per_line, number_of_lines, dpi=300):
+        x, y = super().calculate_size(modules_per_line, number_of_lines, dpi)
+
+        self._xo = (px2mm(self._w)-px2mm(x))/2
+        self._yo = (px2mm(self._h)-px2mm(y))
+        assert self._xo >= 0
+        assert self._yo >= 0
+
+        return int(self._w), int(self._h)
+
+    def _paint_module(self, xpos, ypos, width, color):
+        super()._paint_module(xpos+self._xo, ypos+self._yo, width, color)
+
+    def _paint_text(self, xpos, ypos):
+        super()._paint_text(xpos+self._xo, ypos+self._yo)
+
+    def _finish(self):
+        if self._title:
+            width = self._w+1
+            height = 0
+            max_h = self._h - mm2px(self._yo, self.dpi)
+            fs = int(max_h / 1.2)
+            font = ImageFont.truetype("arial.ttf", 10)
+            while width > self._w or height > max_h:
+                font = ImageFont.truetype("Stranger back in the Night.ttf", fs)
+                width, height = font.getsize(self._title)
+                fs -= 1
+            pos = (
+                (self._w-width)//2,
+                mm2px(0, self.dpi)
+            )
+            self._draw.text(pos, self._title, font=font, fill=self.foreground)
+        return self._image

printer_helpers.py

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+import barcode
+from brother_ql import BrotherQLRaster
+from brother_ql import create_label
+from brother_ql.backends import backend_factory
+
+from barcode_helpers import BrotherLabelWriter
+
+
+def print_bar_code(barcode_value, barcode_text, barcode_type="ean13", rotate=False, printer_type="QL-700",
+                   label_type="62"):
+    bar_coder = barcode.get_barcode_class(barcode_type)
+    wr = BrotherLabelWriter(typ=label_type, rot=rotate*90, text=barcode_text, max_height=1000)
+
+    test = bar_coder(barcode_value, writer=wr)
+    fn = test.save(barcode_value)
+    print_image(fn, printer_type, label_type, rotate*90)
+
+
+def print_image(fn, printer_type="QL-700", label_type="62", rotate=0):
+    qlr = BrotherQLRaster(printer_type)
+    qlr.exception_on_warning = True
+    create_label(qlr, fn, label_type, threshold=70, cut=True, rotate=rotate)
+
+    be = backend_factory("pyusb")
+    list_available_devices = be['list_available_devices']
+    BrotherQLBackend = be['backend_class']
+
+    ad = list_available_devices()
+    assert ad
+    string_descr = ad[0]['string_descr']
+
+    printer = BrotherQLBackend(string_descr)
+
+    printer.write(qlr.data)