@Override
		void showImpl() {
			if( dropShadowDelegate != null )
				showPopupAndFixLocation( dropShadowDelegate, dropShadowWindow );

			if( mediumWeightPanel != null )
				showMediumWeightDropShadow();

			super.showImpl();

			// fix location of light weight popup in case it has left or top drop shadow
			if( lightComp != null ) {
				Insets insets = lightComp.getInsets();
				if( insets.left != 0 || insets.top != 0 )
					lightComp.setLocation( lightComp.getX() - insets.left, lightComp.getY() - insets.top );
			}

			if( popupWindow != null ) {
				removeAllPopupWindowComponentListeners();
				popupWindow.addComponentListener( this );
			}
		}
Fixes popup background flashing effect when using dark theme on light platform theme,
where the light popup background is shown for a fraction of a second before
the dark popup content is shown.
This is fixed by setting popup background to content background.
<p>
Defers hiding of heavy weight popup window for an event cycle,
which allows reusing popup window to avoid flicker when "moving" popup.
flatlaf-core/src/main/java/com/formdev/flatlaf/ui/FlatPopupFactory.java