From 85e894dd73d21b479bcc0d98431e17ed88d583d3 Mon Sep 17 00:00:00 2001
From: KIU Shueng Chuan <nixchuan@gmail.com>
Date: Mon, 1 Mar 2021 13:45:00 +0800
Subject: [PATCH] convert uses of QTimer.singleShot to QTimer instances

On macOS and Linux with PyQt bindings, QTimer.singleShot continues
to fire on python interpreter shutdown.
---
 examples/ImageItem.py      | 8 ++++++--
 examples/PColorMeshItem.py | 7 ++++++-
 2 files changed, 12 insertions(+), 3 deletions(-)

diff --git a/examples/ImageItem.py b/examples/ImageItem.py
index 9982d65c..49141084 100644
--- a/examples/ImageItem.py
+++ b/examples/ImageItem.py
@@ -36,6 +36,10 @@ i = 0
 updateTime = ptime.time()
 fps = 0
 
+timer = QtCore.QTimer()
+timer.setSingleShot(True)
+# not using QTimer.singleShot() because of persistence on PyQt. see PR #1605
+
 def updateData():
     global img, data, i, updateTime, fps
 
@@ -43,7 +47,7 @@ def updateData():
     img.setImage(data[i])
     i = (i+1) % data.shape[0]
 
-    QtCore.QTimer.singleShot(1, updateData)
+    timer.start(1)
     now = ptime.time()
     fps2 = 1.0 / (now-updateTime)
     updateTime = now
@@ -51,7 +55,7 @@ def updateData():
     
     #print "%0.1f fps" % fps
     
-
+timer.timeout.connect(updateData)
 updateData()
 
 ## Start Qt event loop unless running in interactive mode.
diff --git a/examples/PColorMeshItem.py b/examples/PColorMeshItem.py
index 1e5f4e85..44604c8e 100644
--- a/examples/PColorMeshItem.py
+++ b/examples/PColorMeshItem.py
@@ -61,6 +61,10 @@ wave_speed      = 0.3
 wave_length     = 10
 color_speed     = 0.3
 
+timer = QtCore.QTimer()
+timer.setSingleShot(True)
+# not using QTimer.singleShot() because of persistence on PyQt. see PR #1605
+
 i=0
 def updateData():
     global i
@@ -74,8 +78,9 @@ def updateData():
                  new_z)
 
     i += wave_speed
-    QtCore.QTimer.singleShot(1000//fps, updateData)
+    timer.start(1000//fps)
 
+timer.timeout.connect(updateData)
 updateData()
 
 ## Start Qt event loop unless running in interactive mode.