From a752a22a4b860383ae277fb255c79fe97a7c234e Mon Sep 17 00:00:00 2001
From: Tyler Goodlet <jgbt@protonmail.com>
Date: Sat, 23 Apr 2022 15:33:40 -0400
Subject: [PATCH] Handle null output case for vlm chart mxmn

---
 piker/ui/_display.py | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/piker/ui/_display.py b/piker/ui/_display.py
index 36b999d8..0cc6ec81 100644
--- a/piker/ui/_display.py
+++ b/piker/ui/_display.py
@@ -104,7 +104,9 @@ def chart_maxmin(
 
     mx_vlm_in_view = 0
     if vlm_chart:
-        _, mx_vlm_in_view = vlm_chart.maxmin()
+        out = vlm_chart.maxmin()
+        if out:
+            _, mx_vlm_in_view = out
 
     return (
         last_bars_range,