Fix main viewers

printrun/gcview.py

@@ -57,6 +57,9 @@ class GcodeViewPanel(wxGLPanel):
         self.basequat = [0, 0, 0, 1]
         self.mousepos = [0, 0]
 
+    def setlayercb(self, layer):
+        pass
+
     def create_objects(self):
         '''create opengl objects when opengl is initialized'''
         for obj in self.parent.objects:

printrun/gviz.py

@@ -382,6 +382,7 @@ class Gviz(wx.Panel):
         self.clear()
         self.add_parsed_gcodes(gcode.lines)
         max_layers = len(self.layers)
+        if hasattr(self.parent, "layerslider"):
             self.parent.layerslider.SetRange(0, max_layers - 1)
             self.parent.layerslider.SetValue(0)