void (@NotNull EditorEx editor, Color background) { JLabel label = ExpandableSupport.createLabel(createCollapseExtension()); label.setBorder(JBUI.Borders.empty(5, 3, 5, 7)); editor.getContentComponent().putClientProperty(Expandable.class, this); editor.getScrollPane().setHorizontalScrollBarPolicy(ScrollPaneConstants.HORIZONTAL_SCROLLBAR_AS_NEEDED); editor.getScrollPane().setVerticalScrollBarPolicy(ScrollPaneConstants.VERTICAL_SCROLLBAR_ALWAYS); editor.getScrollPane().getVerticalScrollBar().setBackground(background); editor.getScrollPane().getVerticalScrollBar().add(JBScrollBar.LEADING, label); editor.getScrollPane().setViewportBorder(JBUI.Borders.empty(4, 6)); label.setOpaque(true); }