Show a QR code for device-code login (text dialog fallback)

resources/language/resource.language.en_gb/strings.po

@@ -1073,3 +1073,15 @@ msgstr ""
 msgctxt "#30332"
 msgid "Helix API"
 msgstr ""
+
+msgctxt "#30334"
+msgid "Scan the QR code, or go to [B]%s[/B]"
+msgstr ""
+
+msgctxt "#30335"
+msgid "Enter this code: [B]%s[/B]"
+msgstr ""
+
+msgctxt "#30336"
+msgid "Waiting for authorization... (press Back to cancel)"
+msgstr ""

resources/lib/twitch_addon/addon/qr.py

@@ -0,0 +1,82 @@
+# -*- coding: utf-8 -*-
+"""
+
+    Copyright (C) 2024-2025 Twitch-on-Kodi
+
+    This file is part of Twitch-on-Kodi (plugin.video.twitch)
+
+    SPDX-License-Identifier: GPL-3.0-only
+    See LICENSES/GPL-3.0-only for more information.
+
+    Dependency-free QR code -> PNG rendering used by the device-code login flow.
+    Uses the vendored Project Nayuki QR generator (MIT) for the module matrix and
+    a tiny zlib-based PNG writer so no binary image library (PIL/Pillow) is needed.
+"""
+
+import struct
+import zlib
+
+from .vendor.qrcodegen import QrCode
+
+
+def _write_grayscale_png(file_path, width, height, rows):
+    """Write an 8-bit grayscale PNG. ``rows`` is an iterable of ``width``-length
+    bytes objects (one byte per pixel, 0=black .. 255=white)."""
+
+    def chunk(tag, data):
+        out = struct.pack('>I', len(data)) + tag + data
+        out += struct.pack('>I', zlib.crc32(tag + data) & 0xFFFFFFFF)
+        return out
+
+    raw = bytearray()
+    for row in rows:
+        raw.append(0)  # filter type 0 (None) for each scanline
+        raw.extend(row)
+
+    ihdr = struct.pack('>IIBBBBB', width, height, 8, 0, 0, 0, 0)  # 8-bit grayscale
+    png = b'\x89PNG\r\n\x1a\n'
+    png += chunk(b'IHDR', ihdr)
+    png += chunk(b'IDAT', zlib.compress(bytes(raw), 9))
+    png += chunk(b'IEND', b'')
+
+    with open(file_path, 'wb') as handle:
+        handle.write(png)
+    return file_path
+
+
+def generate_qr_png(data, file_path, scale=8, border=4, ecc=None):
+    """Render ``data`` as a QR code PNG at ``file_path``.
+
+    :param scale: pixels per QR module
+    :param border: quiet-zone width in modules (the spec requires >= 4)
+    :returns: ``file_path`` on success
+    """
+    if ecc is None:
+        ecc = QrCode.Ecc.MEDIUM
+    qr = QrCode.encode_text(data, ecc)
+    size = qr.get_size()
+    total = size + 2 * border
+    width = height = total * scale
+
+    rows = []
+    for ty in range(total):
+        line = bytearray(width)
+        for tx in range(total):
+            mx = tx - border
+            my = ty - border
+            dark = (0 <= mx < size) and (0 <= my < size) and qr.get_module(mx, my)
+            value = 0 if dark else 255
+            base = tx * scale
+            for sx in range(scale):
+                line[base + sx] = value
+        packed = bytes(line)
+        for _ in range(scale):
+            rows.append(packed)
+
+    return _write_grayscale_png(file_path, width, height, rows)
+
+
+def generate_solid_png(file_path, width, height, value=18):
+    """Write a solid grayscale rectangle, used as a backdrop panel behind the QR."""
+    row = bytes([value]) * width
+    return _write_grayscale_png(file_path, width, height, (row for _ in range(height)))

resources/lib/twitch_addon/addon/strings.py

@@ -125,6 +125,9 @@
     'device_login_failed': 30304,
     'device_login_cancelled': 30305,
     'device_login_unsupported': 30306,
+    'device_login_scan': 30334,
+    'device_login_code': 30335,
+    'device_login_waiting_cancel': 30336,
     'oauth_refresh_needs_public_client': 30310,
     'device_login_private': 30311,
     'device_login_private_instructions': 30312,

resources/lib/twitch_addon/addon/vendor/__init__.py

@@ -0,0 +1,2 @@
+# -*- coding: utf-8 -*-
+# Vendored third-party libraries.