polished dependency enforcement

portable_computing_toolkit_installer/ui/installer_wizard.py

@@ -303,13 +303,26 @@ class InstallerWizard(QtWidgets.QWizard):
                 #find all checked items and build a set of their dependencies
                 selected = self._get_selections()
                 dependencies_of_selected = set()
+                names_of_dependant_items = []
                 for selected_item in selected:
                     try:
                         dependencies_of_selected |= set((tools_by_name[selected_item.text(0)]["depends on"]).split(","))
                     except KeyError:
                         pass
+                    else:
+                        if item.text(0) in (tools_by_name[selected_item.text(0)]["depends on"]).split(","):
+                            names_of_dependant_items.append(selected_item.text(0))
                 #if the item that was just unchecked is a dependency of another selected item
                 if item.text(0) in dependencies_of_selected:
-                    self._display_error(f"Selected items depend on {item.text(0)}")
+                    #build a gramatically correct error (minus oxford comma (sorry!!))
+                    if len(names_of_dependant_items) > 1:
+                        for name in names_of_dependant_items[1:-1]:
+                            name = f", {name}"
+                        names_of_dependant_items[-1] = f" and {names_of_dependant_items[-1]}"
+                        depend_text = "depend"
+                    else:
+                        depend_text = "depends"
+                    #display the error and disallow unchecking item while something that depends on it is selected
+                    self._display_error(f"{str().join(names_of_dependant_items)} {depend_text} on {item.text(0)}")
                     item.setCheckState(0, QtCore.Qt.Checked)