Component (@Nullable JList<? extends MyFontItem> list, MyFontItem value, int index, boolean isSelected, boolean cellHasFocus) { final var component = super.getListCellRendererComponent(list, value, index, isSelected, cellHasFocus); if (index != -1 || !((MyModel)dataModel).isUpdating()) { return component; } else { JPanel panel = new CellRendererPanel(new BorderLayout()) { @Override public AccessibleContext getAccessibleContext() { return component.getAccessibleContext(); } }; component.setBackground(null); panel.add(component, BorderLayout.CENTER); JBLabel progressIcon = new JBLabel(AnimatedIcon.Default.INSTANCE); panel.add(progressIcon, BorderLayout.EAST); return panel; } }