From 019c421ca102233ba2df27653c723b90a593e09e Mon Sep 17 00:00:00 2001
From: Luke Campagnola <luke.campagnola@gmail.com>
Date: Wed, 24 Jan 2018 17:48:03 -0800
Subject: [PATCH] Don't attempt to set same level mode again

---
 pyqtgraph/graphicsItems/HistogramLUTItem.py | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/pyqtgraph/graphicsItems/HistogramLUTItem.py b/pyqtgraph/graphicsItems/HistogramLUTItem.py
index 90e2e790..f85b64dd 100644
--- a/pyqtgraph/graphicsItems/HistogramLUTItem.py
+++ b/pyqtgraph/graphicsItems/HistogramLUTItem.py
@@ -289,8 +289,10 @@ class HistogramLUTItem(GraphicsWidget):
         """
         assert mode in ('mono', 'rgba')
         
-        oldLevels = self.getLevels()
+        if mode == self.levelMode:
+            return
         
+        oldLevels = self.getLevels()
         self.levelMode = mode
         self._showRegions()