Remove pass through SpectrumViewerWindowPresenter.do_set_roi_alpha()

mantidimaging/gui/windows/spectrum_viewer/presenter.py

@@ -144,15 +144,6 @@ def redraw_all_rois(self) -> None:
             self.model.set_roi(name, self.view.spectrum.get_roi(name))
             self.view.set_spectrum(name, self.model.get_spectrum(name, self.spectrum_mode))
 
-    def do_set_roi_alpha(self, name: str, alpha: float) -> None:
-        """
-        Set the alpha value of the ROI with the given name
-
-        :param name: The name of the ROI
-        :param alpha: The new alpha value (0-255)
-        """
-        self.view.spectrum.set_roi_alpha(name, alpha)
-
     def handle_button_enabled(self) -> None:
         """
         Enable the export button if the current stack is not None and normalisation is valid

mantidimaging/gui/windows/spectrum_viewer/view.py

@@ -250,7 +250,7 @@ def set_roi_alpha(self, alpha: float, roi_name: str) -> None:
 
         @param alpha: The alpha value
         """
-        self.presenter.do_set_roi_alpha(roi_name, alpha)
+        self.spectrum.set_roi_alpha(roi_name, alpha)
         if alpha == 0:
             self.spectrum.spectrum_data_dict[roi_name] = np.zeros(self.spectrum.spectrum_data_dict[roi_name].shape)
         else: