save previews in graphics

src/gui_qt/graphs/graphwindow.py

@@ -48,6 +48,7 @@ class QGraphWindow(QtWidgets.QGraphicsView, Ui_GraphWindow):
         self.error_plots = {}
 
         self._special_needs = []
+        self._external_items = []
         self.closable = True
 
         self.log = [False, False]
@@ -109,7 +110,7 @@ class QGraphWindow(QtWidgets.QGraphicsView, Ui_GraphWindow):
     def __len__(self):
         return len(self.active)
 
-    def curves(self):
+    def curves(self) -> tuple:
         for a in self.active:
             if self.real_button.isChecked():
                 if self.error_plots[a] is not None:
@@ -318,6 +319,7 @@ class QGraphWindow(QtWidgets.QGraphicsView, Ui_GraphWindow):
         if not hasattr(item, 'setLogMode'):
             self._special_needs.append(item)
 
+        self._external_items.append(item)
         self.graphic.addItem(item)
         item.setZValue(1000)
 
@@ -325,12 +327,15 @@ class QGraphWindow(QtWidgets.QGraphicsView, Ui_GraphWindow):
 
     @QtCore.pyqtSlot(GraphicsObject)
     def remove_external(self, item):
-        if item not in self.graphic.items():
-            return False
+        if item in self._external_items:
+            self._external_items.remove(item)
 
         if item in self._special_needs:
             self._special_needs.remove(item)
 
+        if item not in self.graphic.items():
+            return False
+
         self.graphic.removeItem(item)
 
         return True
@@ -599,6 +604,10 @@ class QGraphWindow(QtWidgets.QGraphicsView, Ui_GraphWindow):
             if item_dic:
                 dic['items'].append(item_dic)
 
+        for item in self._external_items:
+            dic['items'].append(item.get_data_opts())
+            in_legend.append(False)
+
         dic['in_legend'] = in_legend
 
         return dic