Safe flag

src/sas/qtgui/Plotting/SlicerModel.py

@@ -1,8 +1,21 @@
+from contextlib import contextmanager
+
 from PySide6 import QtCore, QtGui
 
 import sas.qtgui.Utilities.GuiUtils as GuiUtils
 
 
+@contextmanager
+def temporary_flag(obj, attribute_name, value):
+    """Temporarily set an attribute value and always restore the previous value."""
+    old_value = getattr(obj, attribute_name)
+    setattr(obj, attribute_name, value)
+    try:
+        yield
+    finally:
+        setattr(obj, attribute_name, old_value)
+
+
 class SlicerModel:
     def __init__(self):
         # Model representation of local parameters
@@ -44,9 +57,8 @@ def setParamsFromModel(self):
             else:
                 params[param_name] = float(self._model.item(row_index, 1).text())
 
-        self.update_model = False
-        self.setParams(params)
-        self.update_model = True
+        with temporary_flag(self, "update_model", False):
+            self.setParams(params)
 
     def setParamsFromModelItem(self, item):
         """
@@ -61,9 +73,8 @@ def setParamsFromModelItem(self, item):
         else:
             params[param_name] = float(self._model.item(row_index, 1).text())
 
-        self.update_model = False
-        self.setParams(params)
-        self.update_model = True
+        with temporary_flag(self, "update_model", False):
+            self.setParams(params)
 
     def model(self):
         '''getter for the model'''
@@ -73,7 +84,7 @@ def getParams(self):
         ''' pure virtual '''
         raise NotImplementedError("Parameter getter must be implemented in derived class.")
 
-    def setParams(self):
+    def setParams(self, params):
         ''' pure virtual '''
         raise NotImplementedError("Parameter setter must be implemented in derived class.")
 

src/sas/qtgui/Plotting/Slicers/BoxSum.py

@@ -5,6 +5,7 @@
 
 from sasdata.data_util.manipulations import Boxavg, Boxsum
 
+from sas.qtgui.Plotting.SlicerModel import temporary_flag
 from sas.qtgui.Plotting.Slicers.BaseInteractor import BaseInteractor
 from sas.qtgui.Utilities.GuiUtils import formatNumber, toDouble
 
@@ -150,10 +151,10 @@ def setParamsFromModel(self):
         params["Width"] = toDouble(self.model().item(0, 1).text())
         params["center_x"] = toDouble(self.model().item(0, 2).text())
         params["center_y"] = toDouble(self.model().item(0, 3).text())
-        self.update_model = False
-        self.setParams(params)
-        self.setReadOnlyParametersFromModel()
-        self.update_model = True
+
+        with temporary_flag(self, "update_model", False):
+            self.setParams(params)
+            self.setReadOnlyParametersFromModel()
 
     def setPanelName(self, name):
         """

src/sas/qtgui/Plotting/Slicers/MultiSlicerBase.py

@@ -8,7 +8,7 @@
 
 import numpy as np
 
-from sas.qtgui.Plotting.SlicerModel import SlicerModel
+from sas.qtgui.Plotting.SlicerModel import SlicerModel, temporary_flag
 from sas.qtgui.Plotting.Slicers.BaseInteractor import BaseInteractor
 from sas.qtgui.Plotting.Slicers.SectorSlicer import SectorInteractor
 from sas.qtgui.Plotting.Slicers.SlicerUtils import StackableMixin
@@ -336,15 +336,11 @@ def _synchronized_moveend(self, ev, interactor_name):
         # Now post data for all secondary slicers (with update_model temporarily enabled)
         for i, slicer in enumerate(self.slicers[1:], start=1):
             try:
-                # Temporarily enable model updates for this slicer
-                old_update_model = slicer.update_model
-                slicer.update_model = True
-                with warnings.catch_warnings():
-                    warnings.simplefilter("ignore")
-                    slicer._post_data()
-
-                # Restore original state
-                slicer.update_model = old_update_model
+                # Temporarily enable model updates for this slicer.
+                with temporary_flag(slicer, "update_model", True):
+                    with warnings.catch_warnings():
+                        warnings.simplefilter("ignore")
+                        slicer._post_data()
             except (ValueError, RuntimeError) as e:
                 logger.warning(f"Failed to post data for slicer {i + 1}: {e}")
 

src/sas/qtgui/Plotting/UnitTesting/SlicerModelTest.py

@@ -28,7 +28,7 @@ def testBaseClass(self, qapp):
         '''Assure that SlicerModel contains pure virtuals'''
         model = SlicerModel()
         with pytest.raises(NotImplementedError):
-            model.setParams()
+            model.setParams({})
         with pytest.raises(NotImplementedError):
             model.setModelFromParams()
 
@@ -64,3 +64,48 @@ def testSetParamsFromModel(self, model):
         # Check the new model. The update should be automatic
         assert model.model().rowCount() == 3
         assert model.model().columnCount() == 2
+
+    def testSetParamsFromModel_restores_update_model_on_exception(self, qapp):
+        """update_model should be restored even if setParams raises."""
+        class FailingModel(SlicerModel):
+            params = {"a": 1}
+
+            def __init__(self):
+                SlicerModel.__init__(self)
+
+            def getParams(self):
+                return self.params
+
+            def setParams(self, par):
+                raise RuntimeError("boom")
+
+        model = FailingModel()
+        model.setModelFromParams()
+
+        with pytest.raises(RuntimeError):
+            model.setParamsFromModel()
+
+        assert model.update_model is True
+
+    def testSetParamsFromModelItem_restores_update_model_on_exception(self, qapp):
+        """update_model should be restored for single-item updates too."""
+        class FailingModel(SlicerModel):
+            params = {"a": 1}
+
+            def __init__(self):
+                SlicerModel.__init__(self)
+
+            def getParams(self):
+                return self.params
+
+            def setParams(self, par):
+                raise RuntimeError("boom")
+
+        model = FailingModel()
+        model.setModelFromParams()
+        item = model.model().item(0, 1)
+
+        with pytest.raises(RuntimeError):
+            model.setParamsFromModelItem(item)
+
+        assert model.update_model is True