Refine desktop onboarding and NSIS branding

apps/desktop/scripts/pngs_to_ico.py

@@ -0,0 +1,80 @@
+#!/usr/bin/env python3
+"""
+Utility to build an .ico file from a list of PNGs of different sizes.
+
+Uses only Python's standard library so it can run in restricted environments.
+"""
+
+from __future__ import annotations
+
+import argparse
+import struct
+from pathlib import Path
+
+
+PNG_SIGNATURE = b"\x89PNG\r\n\x1a\n"
+
+
+def read_png_dimensions(data: bytes) -> tuple[int, int]:
+  if not data.startswith(PNG_SIGNATURE):
+    raise ValueError("All inputs must be PNG files.")
+  width, height = struct.unpack(">II", data[16:24])
+  return width, height
+
+
+def build_icon(png_paths: list[Path], output: Path) -> None:
+  png_data = [p.read_bytes() for p in png_paths]
+  entries = []
+  offset = 6 + 16 * len(png_data)  # icon header + entries
+
+  for data in png_data:
+    width, height = read_png_dimensions(data)
+    entry = {
+      "width": width if width < 256 else 0,
+      "height": height if height < 256 else 0,
+      "colors": 0,
+      "reserved": 0,
+      "planes": 1,
+      "bit_count": 32,
+      "size": len(data),
+      "offset": offset,
+      "data": data,
+    }
+    entries.append(entry)
+    offset += entry["size"]
+
+  header = struct.pack("<HHH", 0, 1, len(entries))
+  table = bytearray()
+  for entry in entries:
+    table.extend(
+      struct.pack(
+        "<BBBBHHII",
+        entry["width"],
+        entry["height"],
+        entry["colors"],
+        entry["reserved"],
+        entry["planes"],
+        entry["bit_count"],
+        entry["size"],
+        entry["offset"],
+      )
+    )
+
+  payload = header + table + b"".join(entry["data"] for entry in entries)
+  output.write_bytes(payload)
+
+
+def main() -> None:
+  parser = argparse.ArgumentParser(description=__doc__)
+  parser.add_argument("output", type=Path)
+  parser.add_argument("inputs", nargs="+", type=Path)
+  args = parser.parse_args()
+
+  if not args.inputs:
+    raise SystemExit("Provide at least one PNG input.")
+
+  build_icon(args.inputs, args.output)
+
+
+if __name__ == "__main__":
+  main()