address selection filter review feedback

modules/ui_common.py

@@ -18,6 +18,21 @@ debug('Trace: PASTE')
 warn_once_set = WeakSet()
 
 
+def filter_ui_choices(choices: list[str], preferences: list[str] | None = None, selected: str | None = None) -> tuple[list[str], bool]:
+    """Return display choices while preserving the current selection."""
+    available = list(dict.fromkeys(choices))
+    preferred = set(preferences or [])
+    filtered = [choice for choice in available if choice in preferred]
+    if not filtered:
+        return available, False
+    if selected in available and selected not in filtered:
+        filtered.append(selected)
+    if 'None' in filtered:
+        filtered.remove('None')
+        filtered.insert(0, 'None')
+    return filtered, len(filtered) < len(available)
+
+
 def gr_show(visible=True):
     return {"visible": visible, "__type__": "update"}