From db1e0a04f8cfe9f13594d92e87227f24ad18e19d Mon Sep 17 00:00:00 2001
From: Tyler Goodlet <jgbt@protonmail.com>
Date: Thu, 9 Feb 2023 09:21:04 -0500
Subject: [PATCH] Only use last `ChartView._yrange` if set

---
 piker/ui/_display.py | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/piker/ui/_display.py b/piker/ui/_display.py
index a1958159..a91246e6 100644
--- a/piker/ui/_display.py
+++ b/piker/ui/_display.py
@@ -554,7 +554,12 @@ def graphics_update_cycle(
     main_vb: ChartView = main_viz.plot.vb
     this_viz: Viz = chart._vizs[fqsn]
     this_vb: ChartView = this_viz.plot.vb
-    lmn, lmx = this_vb._yrange
+    this_yr = this_vb._yrange
+    if this_yr:
+        lmn, lmx = this_yr
+    else:
+        lmn = lmx = 0
+
     mx: float = lmx
     mn: float = lmn
     mx_vlm_in_view: float | None = None