Show time label on top of ruler

Closes #71 (closed)

sohstationviewer/view/plotting/plotting_widget/plotting_widget.py

@@ -471,12 +471,17 @@ class PlottingWidget(QtWidgets.QScrollArea):
         :param event: QKeyEvent - event to know what key is pressed
         """
         if event.key() == QtCore.Qt.Key_Escape:
+            try:
+                self.ruler_text.remove()
+                self.ruler_text = None
+            except AttributeError:
+                pass
             for w in self.peer_plotting_widgets:
                 w.set_rulers_invisible()
                 w.zoom_marker1_shown = False
                 try:
-                    self.ruler_text.remove()
-                    self.ruler_text = None
+                    w.ruler_text.remove()
+                    w.ruler_text = None
                 except AttributeError:
                     pass
                 w.draw()