use warn_deprecated

Author: ahaldane

lib/matplotlib/backend_bases.py

@@ -60,7 +60,7 @@
 import matplotlib.tight_bbox as tight_bbox
 import matplotlib.textpath as textpath
 from matplotlib.path import Path
-from matplotlib.cbook import mplDeprecation
+from matplotlib.cbook import mplDeprecation, warn_deprecated
 import matplotlib.backend_tools as tools
 
 try:
@@ -2332,9 +2332,10 @@ def on_press(event):
 
         """
         if s == 'idle_event':
-            warnings.warn("idle_event is only implemented for the wx backend, "
-                          "and will be removed in matplotlib 2.1. Use the "
-                          "animations module instead.", mplDeprecation)
+            warn_deprecated(1.5,
+                "idle_event is only implemented for the wx backend, and will "
+                "be removed in matplotlib 2.1. Use the animations module "
+                "instead.")
 
         return self.callbacks.connect(s, func)