WaiterOverlay: fix parenting since is a QWidget

src/silx/gui/utils/test/test_waiter_overlay.py

@@ -12,6 +12,7 @@ def test_show(qapp_utils):
     waitingOverlay.setWaiting(False)
 
     assert waitingOverlay.parent() is plot
+    assert waitingOverlay._waitingButton.parent() is plot.getWidgetHandle()
 
     plot.close()
     waitingOverlay.close()

src/silx/gui/utils/waiteroverlay.py

@@ -11,13 +11,13 @@ def __init__(self, parent: qt.QWidget) -> None:
         :param qt.QWidget underlying_widget: widget on top of which we want to displat the "processing/waiting wheel"
         :param str waiting_text: text to apply near the processing wheel
         """
-        super().__init__()
-
+        super().__init__(parent)
         if isinstance(parent, PlotWidget):
             parent = parent.getWidgetHandle()
 
         if not isinstance(parent, qt.QWidget):
             raise TypeError(f"underlying_widget is expected to be an instance of QWidget. {type(parent)} provided.")
+
         self._waitingButton = WaitingPushButton(
             parent=parent,
         )