[communicator] add signal for plotting errors and use it

nixview/communicator.py

@@ -9,4 +9,6 @@ class Communicate(QObject):
     
     item_selected = pyqtSignal(NixTreeItem)
     
+    plot_error = pyqtSignal(str)
+     
 communicator = Communicate()

nixview/ui/mainwindow.py

@@ -1,7 +1,6 @@
-import os
 import sys
 from PyQt5.QtWidgets import QWidget, QFileDialog, QMainWindow, QMenuBar, QToolBar, QAction, QStatusBar, QSizePolicy
-from PyQt5.QtGui import QIcon, QKeySequence
+from PyQt5.QtGui import QKeySequence
 from PyQt5.QtCore import QSize, QSettings, Qt
 
 from nixview.util.file_handler import FileHandler, NodeType
@@ -30,6 +29,7 @@ class NixView(QMainWindow):
 
         comm.communicator.open_recent.connect(self.on_open_recent)
         comm.communicator.item_selected.connect(self.on_item_selected)
+        comm.communicator.plot_error.connect(self.on_plot_error)
         self.show()
 
     def on_open_recent(self, event):
@@ -167,6 +167,9 @@ class NixView(QMainWindow):
         if self._current_item is not None:
             self._cw.plot_item(self._current_item.node_descriptor)
 
+    def on_plot_error(self, s):
+        self.statusBar().showMessage(s, 5000)
+
     def on_about(self, e):
         about = AboutDialog(self)
         about.show()

nixview/ui/plotscreen.py

@@ -11,6 +11,7 @@ from matplotlib.widgets import Slider
 
 from nixview.util.file_handler import FileHandler
 from nixview.util.dataview import DataView
+from nixview.communicator import communicator
 
 
 def create_label(entity):
@@ -347,9 +348,9 @@ class PlotScreen(QWidget):
         try:
             self._data_view = DataView(item, self._file_handler)
         except ValueError as e:
-            print("error in plotscreen.plot", e)
+            communicator.plot_error.emit("error in plotscreen.plot %s" % e)
             return
+        
         self._data_view.request_more() # TODO this is just a test, needs to be removed
         print(self._data_view)
 
-