Add a QR code label generation example

demos/qr.py

@@ -0,0 +1,49 @@
+# This file is part of pylabels, a Python library to create PDFs for printing
+# labels.
+# Copyright (C) 2012, 2013, 2014 Blair Bonnett
+#
+# pylabels is free software: you can redistribute it and/or modify it under the
+# terms of the GNU General Public License as published by the Free Software
+# Foundation, either version 3 of the License, or (at your option) any later
+# version.
+#
+# pylabels is distributed in the hope that it will be useful, but WITHOUT ANY
+# WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
+# A PARTICULAR PURPOSE.  See the GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License along with
+# pylabels.  If not, see <http://www.gnu.org/licenses/>.
+
+import labels
+from reportlab.graphics.barcode import qr
+
+# Create an A4 portrait (210mm x 297mm) sheets with 2 columns and 8 rows of
+# labels. Each label is 90mm x 25mm with a 2mm rounded corner. The margins are
+# automatically calculated.
+specs = labels.Specification(210, 297, 2, 8, 90, 25, corner_radius=2)
+
+# Create a function to draw each label. This will be given the ReportLab drawing
+# object to draw on, the dimensions (NB. these will be in points, the unit
+# ReportLab uses) of the label, and the object to render.
+def draw_label(label, width, height, obj):
+    # draw a QR code
+    qr_code = qr.QrCodeWidget(str(obj), barLevel = 'H', 
+        barHeight = height, barWidth = width)
+    label.add(qr_code)
+
+# Create the sheet.
+sheet = labels.Sheet(specs, draw_label, border=True)
+
+# Add a couple of labels.
+sheet.add_label("Hello")
+sheet.add_label("World")
+
+# We can also add each item from an iterable.
+sheet.add_labels(range(3, 22))
+
+# We can embed URLs in the QR codes too
+sheet.add_label("https://github.com/bcbnz/pylabels")
+
+# Save the file and we are done.
+sheet.save('qr.pdf')
+print("{0:d} label(s) output on {1:d} page(s).".format(sheet.label_count, sheet.page_count))