Redraw only after some delay (reuse market search delay for that)

gui/graph.py

@@ -54,6 +54,14 @@ class Graph(metaclass=ABCMeta):
     def yDefs(self):
         raise NotImplementedError
 
+    @property
+    def hasTargets(self):
+        return False
+
+    @property
+    def hasVectors(self):
+        return False
+
     @property
     def redrawOnEffectiveChange(self):
         return False