Assembly: Simulation: Fix motion double click (#23778)

* Assembly: Simulation: Fix motion double click

* [pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci

---------

Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>

src/Mod/Assembly/CommandCreateSimulation.py

@@ -358,7 +358,7 @@ class Motion:
     def getAssembly(self, feaPy):
         simulation = self.getSimulation(feaPy)
         if simulation is not None:
-            return simulation.getAssembly()
+            return simulation.Proxy.getAssembly(simulation)
         return None
 
 
@@ -370,7 +370,6 @@ class ViewProviderMotion:
     def attach(self, vpDoc):
         """Setup the scene sub-graph of the view provider, this method is mandatory"""
         self.app_obj = vpDoc.Object
-        self.assembly = self.app_obj.Proxy.getAssembly(self.app_obj)
 
         self.display_mode = coin.SoType.fromName("SoFCSelection").createInstance()
 
@@ -411,22 +410,19 @@ class ViewProviderMotion:
         return None
 
     def doubleClicked(self, vpDoc):
-        if self.assembly is None:
-            return False
-
-        if UtilsAssembly.activeAssembly() != self.assembly:
-            Gui.ActiveDocument.setEdit(self.assembly)
-
         self.openEditDialog()
 
     def openEditDialog(self):
+        assembly = self.getAssembly()
+
+        if assembly is None:
+            return False
+
         joint = None
         if self.app_obj.Joint is not None:
             joint = self.app_obj.Joint[0]
 
-        dialog = MotionEditDialog(
-            self.assembly, self.app_obj.MotionType, joint, self.app_obj.Formula
-        )
+        dialog = MotionEditDialog(assembly, self.app_obj.MotionType, joint, self.app_obj.Formula)
         if dialog.exec_():
             self.app_obj.MotionType = dialog.motionType
             self.app_obj.Joint = dialog.joint
@@ -444,6 +440,17 @@ class ViewProviderMotion:
             label=self.app_obj.Joint[0].Label, type_=translate("Assembly", typeStr)
         )
 
+    def getAssembly(self):
+        assembly = self.app_obj.Proxy.getAssembly(self.app_obj)
+
+        if assembly is None:
+            return None
+
+        if UtilsAssembly.activeAssembly() != assembly:
+            Gui.ActiveDocument.setEdit(assembly)
+
+        return assembly
+
 
 class MotionEditDialog:
     def __init__(self, assembly, motionType=MotionTypes[0], joint=None, formula="5*time"):