Check for already running QApplication in Qt embedding example.

anntzer · anntzer · commit 89edd733aef9 · 2019-03-22T11:30:55.000+01:00
diff --git a/examples/user_interfaces/embedding_in_qt_sgskip.py b/examples/user_interfaces/embedding_in_qt_sgskip.py
@@ -58,7 +58,12 @@ def _update_canvas(self):
 
 
 if __name__ == "__main__":
-    qapp = QtWidgets.QApplication(sys.argv)
+    # Check whether there is already a running QApplication (e.g., if running
+    # from an IDE).
+    qapp = QtWidgets.QApplication.instance()
+    if not qapp:
+        qapp = QtWidgets.QApplication(sys.argv)
+
     app = ApplicationWindow()
     app.show()
     qapp.exec_()
