Scenario: Save dialog at scenarios switch.

src/View/Scenarios/GraphWidget.py

@@ -31,7 +31,7 @@ from PyQt5.QtGui import (
 )
 from PyQt5.QtWidgets import (
     QApplication, QGraphicsScene, QGraphicsView,
-    QGraphicsItem, QGraphicsTextItem, QMenu,
+    QGraphicsItem, QGraphicsTextItem, QMenu, QMessageBox,
 )
 
 from View.WaitingDialog import WaitingDialog
@@ -410,13 +410,37 @@ class GraphWidget(QGraphicsView):
         )
         m.run()
 
+    def dialog_save(self):
+        dlg = QMessageBox(self)
+
+        dlg.setWindowTitle(self._trad["mb_save_title"])
+        dlg.setText(self._trad["mb_save_msg"])
+        opt = QMessageBox.Save | QMessageBox.Cancel
+
+        dlg.setStandardButtons(opt)
+        dlg.setIcon(QMessageBox.Warning)
+        dlg.button(QMessageBox.Save).setText(self._trad["Save"])
+        dlg.button(QMessageBox.Cancel).setText(self._trad["Cancel"])
+
+        res = dlg.exec()
+
+        if res == QMessageBox.Save:
+            return True
+        elif res == QMessageBox.Cancel:
+            return False
+
     def select_scenario(self, item):
         if type(item) is not ScenarioItem:
             return
 
+        must_saved = self.dialog_save()
+
         def fn():
             self._close_other_window()
-            self._study.save()
+
+            if must_saved:
+                self._study.save()
+
             self._undo.push(
                 SelectScenariosCommand(
                     self._study,