Gui: add MDIViewPy.cast_to_base and implement in Python wrappers for sub-classes of MDIView

src/Mod/Spreadsheet/Gui/SpreadsheetView.cpp

@@ -471,6 +471,7 @@ void SheetViewPy::init_type()
     behaviors().supportSetattr();
 
     add_varargs_method("getSheet", &SheetViewPy::getSheet, "getSheet()");
+    add_varargs_method("cast_to_base", &SheetViewPy::cast_to_base, "cast_to_base() cast to MDIView class");
     behaviors().readyType();
 }
 
@@ -531,4 +532,9 @@ Py::Object SheetViewPy::getSheet(const Py::Tuple& args)
     return Py::asObject(new Spreadsheet::SheetPy(getSheetViewPtr()->getSheet()));
 }
 
+Py::Object SheetViewPy::cast_to_base(const Py::Tuple&)
+{
+    return Gui::MDIViewPy::create(base.getMDIViewPtr());
+}
+
 #include "moc_SpreadsheetView.cpp"