Merge pull request #5020 from 0penBrain/placement

[Gui] Edit/Placement not active when no object selected

src/Gui/CommandDoc.cpp

@@ -1574,7 +1574,7 @@ void StdCmdPlacement::activated(int iMsg)
 
 bool StdCmdPlacement::isActive(void)
 {
-    return (Gui::Control().activeDialog()==0);
+    return Gui::Selection().countObjectsOfType(App::GeoFeature::getClassTypeId()) == 1;
 }
 
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