From 1f534fac83031fa7eeb7eb2a05bab4de92b217e7 Mon Sep 17 00:00:00 2001
From: wakonig_k <klaus.wakonig@psi.ch>
Date: Wed, 20 May 2026 20:40:02 +0200
Subject: [PATCH] wip

---
 bec_widgets/utils/ui_loader.py | 46 +++++++++++++++++++++++++++++++---
 1 file changed, 43 insertions(+), 3 deletions(-)

diff --git a/bec_widgets/utils/ui_loader.py b/bec_widgets/utils/ui_loader.py
index 17c3bdb9..857601e2 100644
--- a/bec_widgets/utils/ui_loader.py
+++ b/bec_widgets/utils/ui_loader.py
@@ -1,6 +1,6 @@
 from bec_lib.logger import bec_logger
 from qtpy import PYSIDE6
-from qtpy.QtCore import QFile, QIODevice
+from qtpy.QtCore import QEvent, QFile, QIODevice, QObject
 
 from bec_widgets.utils.plugin_utils import get_designer_plugin
 
@@ -9,16 +9,56 @@ logger = bec_logger.logger
 if PYSIDE6:
     from qtpy.QtUiTools import QUiLoader
 
+    class _LoadedUiCloser(QObject):
+        """Forward root close events to widgets instantiated by ``QUiLoader``.
+
+        Destroying a parent widget does not guarantee ``closeEvent`` is delivered to
+        every child widget. Some of our designer plugins rely on ``closeEvent`` /
+        ``cleanup`` to unregister callbacks, so explicitly close loaded descendants
+        when the loaded form itself is closed.
+        """
+
+        def __init__(self, root_widget):
+            super().__init__(root_widget)
+            self._root_widget = root_widget
+            self._widgets = []
+            root_widget.installEventFilter(self)
+
+        def register_widget(self, widget):
+            if widget is None or widget is self._root_widget:
+                return
+            self._widgets.append(widget)
+
+        def eventFilter(self, watched, event):
+            if watched is self._root_widget and event.type() == QEvent.Close:
+                for widget in reversed(self._widgets):
+                    try:
+                        widget.close()
+                    except RuntimeError:
+                        continue
+            return super().eventFilter(watched, event)
+
     class CustomUiLoader(QUiLoader):
         def __init__(self, baseinstance):
             super().__init__(baseinstance)
             self.baseinstance = baseinstance
+            self._closer = _LoadedUiCloser(baseinstance) if baseinstance is not None else None
 
         def createWidget(self, class_name, parent=None, name=""):
+            if parent is None and self.baseinstance is not None:
+                return self.baseinstance
+
+            widget_parent = parent if parent is not None else self.baseinstance
             widget = get_designer_plugin(class_name, raise_on_missing=False)
             if widget is not None:
-                return widget(self.baseinstance)
-            return super().createWidget(class_name, self.baseinstance, name)
+                created_widget = widget(widget_parent)
+                created_widget.setObjectName(name)
+            else:
+                created_widget = super().createWidget(class_name, widget_parent, name)
+
+            if self._closer is not None:
+                self._closer.register_widget(created_widget)
+            return created_widget
 
 
 class UILoader: