From ba43b54175a06f62195bed073db90a0849b9c6fe Mon Sep 17 00:00:00 2001
From: Tyler Goodlet <jgbt@protonmail.com>
Date: Wed, 15 Jun 2022 08:58:01 -0400
Subject: [PATCH] Handle edge case for extreme zoom out

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

diff --git a/piker/ui/_flows.py b/piker/ui/_flows.py
index 01e7159b..5f92b429 100644
--- a/piker/ui/_flows.py
+++ b/piker/ui/_flows.py
@@ -750,8 +750,13 @@ class Flow(msgspec.Struct):  # , frozen=True):
             y = y[-uppx:]
             ymn, ymx = y.min(), y.max()
             # print(f'drawing uppx={uppx} mxmn line: {ymn}, {ymx}')
+            try:
+                iuppx = x[-uppx]
+            except IndexError:
+                iuppx = x
+
             dsg._last_line = QLineF(
-                x[-uppx], ymn,
+                iuppx, ymn,
                 x[-1], ymx,
             )
             # print(f'updating DS curve {self.name}')