From 052d3efefabd43850a7e501bc42b6cb6ea8b66df Mon Sep 17 00:00:00 2001
From: dev <dev@local>
Date: Sun, 22 Feb 2026 15:55:12 +0000
Subject: [PATCH] feat(entry): implement def _detect_backend_from_qpa_env

---
 scanslicer/entry.py | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/scanslicer/entry.py b/scanslicer/entry.py
index 8fc4ad8..c720416 100644
--- a/scanslicer/entry.py
+++ b/scanslicer/entry.py
@@ -21,3 +21,18 @@ def parse_args(argv=None):
         help="Display backend selection (default: auto)",
     )
     return parser.parse_args(argv)
+
+
+# _detect_backend_from_qpa_env: function definition for ScanSlicer behavior.
+def _detect_backend_from_qpa_env():
+    qpa_value = os.environ.get("QT_QPA_PLATFORM", "").strip().lower()
+    if not qpa_value:
+        return None
+
+    tokens = [token.strip() for token in qpa_value.split(";") if token.strip()]
+    for token in tokens:
+        if token == "wayland":
+            return "wayland"
+        if token in ("xcb", "x11"):
+            return "x11"
+    return None