Shorten wx _onMouseWheel.

anntzer · anntzer · commit 8dcf80bf5ddf · 2019-12-21T16:35:42.000+01:00
Just compress down the code a bit.
diff --git a/lib/matplotlib/backends/backend_wx.py b/lib/matplotlib/backends/backend_wx.py
@@ -811,22 +811,14 @@ def _onMouseButton(self, evt):
 
     def _onMouseWheel(self, evt):
         """Translate mouse wheel events into matplotlib events"""
-
         # Determine mouse location
         x = evt.GetX()
         y = self.figure.bbox.height - evt.GetY()
-
         # Convert delta/rotation/rate into a floating point step size
-        delta = evt.GetWheelDelta()
-        rotation = evt.GetWheelRotation()
-        rate = evt.GetLinesPerAction()
-        step = rate * rotation / delta
-
+        step = evt.LinesPerAction * evt.WheelRotation / evt.WheelDelta
         # Done handling event
         evt.Skip()
-
-        # Mac is giving two events for every wheel event
-        # Need to skip every second one
+        # Mac gives two events for every wheel event; skip every second one.
         if wx.Platform == '__WXMAC__':
             if not hasattr(self, '_skipwheelevent'):
                 self._skipwheelevent = True
@@ -835,7 +827,6 @@ def _onMouseWheel(self, evt):
                 return  # Return without processing event
             else:
                 self._skipwheelevent = True
-
         FigureCanvasBase.scroll_event(self, x, y, step, guiEvent=evt)
 
     def _onMotion(self, evt):
