Add dependency info to README.md

FFI used in the project uses bytes instead of str for writing purposes.

README.md

@@ -1 +1,17 @@
-Use the source, luke :^)
+# Hackerspace Label Printing Interface
+
+Web interface for accessing label printers on the premises of Warsaw Hackerspace. Currently only supports DYMO LabelWriter 450.
+
+## Dependencies
+
+This project relies on external dependencies:
+
+- `cairo`, `pango`, `pangocairo` for graphics manipulation
+- `CUPS` for interfacing with the printer over local network
+
+## Building and debugging 
+
+```
+poetry install
+poetry run python render.py
+```

pyproject.toml

@@ -0,0 +1,18 @@
+[tool.poetry]
+name = "labelmaker"
+version = "0.1.0"
+description = "Web interface for accessing label printers available at hswaw"
+authors = ["Your Name <you@example.com>"]
+readme = "README.md"
+
+[tool.poetry.dependencies]
+python = "^3.12"
+flask = "^3.0.0"
+cairocffi = "^1.6.1"
+pangocffi = "^0.12.0"
+pangocairocffi = "^0.7.0"
+
+
+[build-system]
+requires = ["poetry-core"]
+build-backend = "poetry.core.masonry.api"

render.py

@@ -1,15 +1,15 @@
-import json
+
 import math
 import os
-import StringIO
+import io
 import subprocess
-import tempfile
 import time
 
-import cairo
+import cairocffi as cairo
 import flask
-import pango
+from flask import json
-import pangocairo
+import pangocffi as pango
+import pangocairocffi as pangocairo
 
 class App(flask.Flask):
     def __init__(self, *args, **kwargs):
@@ -50,26 +50,26 @@ class Renderer(object):
         if y != -1:
             self.context.translate(x, y)
 
-        pangocairo_context = pangocairo.CairoContext(self.context)
+        self.context.set_antialias(cairo.ANTIALIAS_SUBPIXEL)
-        pangocairo_context.set_antialias(cairo.ANTIALIAS_SUBPIXEL)
+        layout = pangocairo.create_layout(self.context)
-        layout = pangocairo_context.create_layout()
+        layout.width = pango.units_from_double(self.width)
-        layout.set_width(self.width*pango.SCALE)
+        layout.alignment = pango.Alignment.CENTER
-        layout.set_alignment(pango.ALIGN_CENTER)
 
         if html:
             # Absolutely horrifying hack to fix broken text wrapping
-            layout.set_markup('<span font_desc="%s">%s</span>' % (fontname, text))
+            layout.apply_markup('<span font_desc="%s">%s</span>' % (fontname, text))
         else:
-            font = pango.FontDescription(fontname)
+            font = pango.FontDescription()
-            layout.set_font_description(font)
+            font.family = fontname
-            layout.set_text(text)
+            layout.font_description = font
+            layout.text = text
 
         if y == -1:
-            self.context.translate(0, (self.height - layout.get_size()[1]/pango.SCALE)/2)
+            self.context.translate(0, (self.height - pango.units_to_double(layout.get_size()[1]))/2)
 
         self.context.set_source_rgb(0, 0, 0)
-        pangocairo_context.update_layout(layout)
+        pangocairo.update_layout(self.context, layout)
-        pangocairo_context.show_layout(layout)
+        pangocairo.show_layout(self.context, layout)
 
         self.context.restore()
 
@@ -81,10 +81,10 @@ def healthcheck():
     last_checked, last_status, last_details = app.health
     if time.time() - last_checked < 1:
         return last_status, last_details
-    output = subprocess.check_output(['lpstat', '-p', '-d'])
+    output = subprocess.run(['lpstat', '-p', '-d'], capture_output=True).stdout
     mark = False
-    for line in output.split('\n'):
+    for line in output.split(b'\n'):
-        line = line.strip()
+        line = line.strip().decode('utf-8')
         if line.startswith('printer DYMO_LabelWriter_450'):
             if 'is idle.' in line:
                 return True, 'Idle'
@@ -98,6 +98,8 @@ def healthcheck():
                 app.health = (time.time(), False, line)
                 return False, line
         mark = False
+    return False, 'Printer is down or there\'s something wrong with lpstat output.'
+
 
 @app.route('/health')
 def health():
@@ -111,7 +113,7 @@ def stuff_preview(size):
     r = Renderer()
     r.render_text(text, 'Sans {}'.format(size), 0, -1, html)
 
-    sio = StringIO.StringIO()
+    sio = io.BytesIO()
     r.surface.write_to_png(sio)
     sio.seek(0)
     return flask.send_file(sio, mimetype='image/png')
@@ -122,7 +124,7 @@ def stuff_print(size):
     if not healthcheck()[0]:
         return 'Printer is down.'
     last = app.last
-    print last, time.time() - last
+    print((last, time.time() - last))
     if time.time() - last < DELAY:
         return 'Please wait {} more seconds before next print.'.format(int(DELAY - (time.time() - last)))
     text = flask.request.args.get('text')
@@ -130,7 +132,7 @@ def stuff_print(size):
     r = Renderer()
     r.render_text(text, 'Sans {}'.format(size), 0, -1, html)
     path = '/tmp/hslabel'
-    f = open(path, 'w')
+    f = open(path, 'wb')
 
     r.surface.write_to_png(f)
     f.flush()

templates/index.html

@@ -90,8 +90,9 @@ $ curl -d "" http://label.waw.hackerspace.pl/stuff/print/60/?text=foobar&htm
     </div>
     <footer class="footer">
         <div class="container">
-            <p class="text-muted" style="margin: 20px 0;">Cobbled together by <a href="https://q3k.org/">q3k</a>. Sauce
+            <p class="text-muted" style="margin: 20px 0;">Cobbled together by <a href="https://q3k.org/">q3k</a>,
-                on <a href="https://code.hackerspace.pl/q3k/labelmaker">code.hackerspace.pl/q3k/labelmaker</a></p>
+                updated to Python 3 by vibe. Sauce
+                on <a href="https://code.hackerspace.pl/hswaw/labelmaker">code.hackerspace.pl/hswaw/labelmaker</a></p>
         </div>
     </footer>
     <script src="https://code.jquery.com/jquery-2.1.4.min.js"></script>