Re #30308 Fix memory leak in slice viewer of ADS Observer

qt/python/mantidqt/widgets/sliceviewer/adsobsever.py

@@ -44,10 +44,7 @@ class SliceViewerADSObserver(AnalysisDataServiceObserver):
         self.observeRename(True)
 
     def __del__(self):
-        self.observeClear(False)
-        self.observeDelete(False)
-        self.observeReplace(False)
-        self.observeRename(False)
+        self.observeAll(False)
 
     @_catch_exceptions
     def clearHandle(self):

qt/python/mantidqt/widgets/sliceviewer/peaksviewer/presenter.py

@@ -162,14 +162,15 @@ class PeaksViewerCollectionPresenter:
         """
         self._view = view
         self._child_presenters = []
+        self._ads_observer = None
+        self.setup_ads_observer()
 
-        # Setup ADS observer
-        self._ads_observer = SliceViewerADSObserver(self.replace_handle, self.rename_handle, self.clear_handle,
-                                                    self.delete_handle)
+    def setup_ads_observer(self):
+        if self._ads_observer is None:
+            self._ads_observer = SliceViewerADSObserver(self.replace_handle, self.rename_handle, self.clear_handle,
+                                                        self.delete_handle)
 
-    def close_called(self):
-        self._view = None
-        self._child_presenters = []
+    def clear_observer(self):
         self._ads_observer = None
 
     @property
@@ -182,6 +183,7 @@ class PeaksViewerCollectionPresenter:
         :param name: The name of a PeaksWorkspace.
         :returns: The child presenter
         """
+        self.setup_ads_observer()
         presenter = PeaksViewerPresenter(self._create_peaksviewer_model(name),
                                          self._view.append_peaksviewer())
         self._child_presenters.append(presenter)
@@ -219,6 +221,7 @@ class PeaksViewerCollectionPresenter:
         Remove the named workspace from display. No op if no workspace can be found with that name
         :param name: The name of a workspace
         """
+        self.setup_ads_observer()
         child_presenters = self._child_presenters
         presenter_to_remove = None
         for child in child_presenters:
@@ -241,6 +244,7 @@ class PeaksViewerCollectionPresenter:
 
     def notify(self, event):
         """Dispatch notification to all subpresenters"""
+        self.setup_ads_observer()
         for presenter in self._child_presenters:
             presenter.notify(event)
 

qt/python/mantidqt/widgets/sliceviewer/presenter.py

@@ -396,6 +396,8 @@ class SliceViewer(ObservingPresenter):
 
     def clear_observer(self):
         self.ads_observer = None
+        if self._peaks_presenter is not None:
+            self._peaks_presenter.clear_observer()
 
     # private api
     def _create_peaks_presenter_if_necessary(self):
@@ -447,7 +449,3 @@ class SliceViewer(ObservingPresenter):
     def _close_view_with_message(self, message: str):
         self.view.emit_close()  # inherited from ObservingView
         self._logger.warning(message)
-
-    def close_called(self):
-        if self._peaks_presenter is not None:
-            self._peaks_presenter.close_called()

qt/python/mantidqt/widgets/sliceviewer/view.py

@@ -611,5 +611,6 @@ class SliceViewerView(QWidget, ObservingView):
     def _on_rename(self, new_title):
         self.setWindowTitle(new_title)
 
-    def closeEvent(self, _):
-        self.presenter.close_called()
+    def closeEvent(self, event):
+        super().closeEvent(event)
+        self.presenter.clear_observer()