Fix default pixel data and handle no pixel data

blink1073 · blink1073 · commit 1429206fa211 · 2015-03-17T15:56:22.000-05:00
diff --git a/lib/matplotlib/artist.py b/lib/matplotlib/artist.py
@@ -907,7 +907,7 @@ def get_pixel_data(self, event):
         """
         Get the pixel data for a given event.
         """
-        return ''
+        return None
 
     def format_pixel_data(self, data):
         """
diff --git a/lib/matplotlib/backend_bases.py b/lib/matplotlib/backend_bases.py
@@ -2800,8 +2800,9 @@ def mouse_move(self, event):
                 artists.sort(key=lambda x: x.zorder)
                 if artists:
                     a = artists[-1]
-                    data = a.get_cursor_data(event)
-                    s += 'data= %s' % a.format_cursor_data(data)
+                    data = a.get_pixel_data(event)
+                    if data is not None:
+                        s += ' data=%s' % a.format_pixel_data(data)
                 if len(self.mode):
                     self.set_message('%s, %s' % (self.mode, s))
                 else:
