From e75738d9b40553a04e1ada1f2b6ba46960ccdd03 Mon Sep 17 00:00:00 2001
From: Tim Hoffmann <2836374+timhoffm@users.noreply.github.com>
Date: Sun, 2 Jun 2019 20:09:33 +0200
Subject: [PATCH] Backport PR #14285: DOC: add note to example about keeping
 hard-ref to SpanSelector

---
 examples/widgets/span_selector.py | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/examples/widgets/span_selector.py b/examples/widgets/span_selector.py
index e3516b0ef7de..c98b6640e929 100644
--- a/examples/widgets/span_selector.py
+++ b/examples/widgets/span_selector.py
@@ -38,9 +38,17 @@ def onselect(xmin, xmax):
     ax2.set_ylim(thisy.min(), thisy.max())
     fig.canvas.draw()
 
-# Set useblit=True on most backends for enhanced performance.
+#############################################################################
+# .. note
+#
+#    If the SpanSelector object is garbage collected you will lose the
+#    interactivity.  You must keep a hard reference to it to prevent this.
+#
+
+
 span = SpanSelector(ax1, onselect, 'horizontal', useblit=True,
                     rectprops=dict(alpha=0.5, facecolor='red'))
+# Set useblit=True on most backends for enhanced performance.
 
 
 plt.show()