store ListEntry enabled/disabled state, honor state when creating new entries

listentry.py

@@ -10,6 +10,7 @@ class ListEntry(wx.BoxSizer):
         self.style = style
         self.entries = []
         self.SetValue(value)
+        self._enabled = True
 
 
     def SetValue(self, value):
@@ -17,6 +18,8 @@ class ListEntry(wx.BoxSizer):
         self.Clear(True)
         for v in value:
             new = MathEntry(self.parent, value=v, style=self.style)
+            if not self._enabled:
+                new.Disable()
             self.entries.append(new)
             self.Add(new, flag=wx.EXPAND)
 
@@ -25,9 +28,11 @@ class ListEntry(wx.BoxSizer):
         return [e.GetValue() for e in self.entries]
 
     def Disable(self):
+        self._enabled = False
         return [e.Disable() for e in self.entries]
 
     def Enable(self):
+        self._enabled = True
         return [e.Enable() for e in self.entries]