Code to compile a single qrc file

src/calibre/gui2/rcc/__init__.py

@@ -0,0 +1,29 @@
+#!/usr/bin/env python
+# vim:fileencoding=utf-8
+# License: GPL v3 Copyright: 2022, Kovid Goyal <kovid at kovidgoyal.net>
+
+import os
+import sys
+from qt.core import QFile, QIODevice
+
+from calibre_extensions import rcc_backend
+
+
+def compile_qrc(output_path, *qrc_file_paths):
+    rcc = rcc_backend.RCCResourceLibrary()
+    err_device = QFile()
+    if not err_device.open(sys.stderr.fileno(), QIODevice.OpenModeFlag.WriteOnly | QIODevice.OpenModeFlag.Text):
+        raise ValueError('Failed to open stderr for writing')
+    if not qrc_file_paths:
+        raise TypeError('Must specify at least one .qrc file')
+    rcc.setInputFiles(list(qrc_file_paths))
+    if not rcc.readFiles(False, err_device):
+        raise ValueError('Failed to read qrc files')
+    with open(output_path, 'wb') as f:
+        out = QFile(output_path)
+        if not out.open(f.fileno(), QIODevice.OpenModeFlag.WriteOnly):
+            raise RuntimeError(f'Failed to open {output_path} for writing')
+        ok = rcc.output(out, QFile(), err_device)
+    if not ok:
+        os.remove(output_path)
+        raise ValueError('Failed to write output')

src/calibre/gui2/rcc/rcc.sip

@@ -26,7 +26,7 @@ class RCCResourceLibrary /NoDefaultCtors/
 %End
 
 public:
-    RCCResourceLibrary(quint8 formatVersion);
+    RCCResourceLibrary(quint8 formatVersion=3);
     ~RCCResourceLibrary();