JComponent (@NotNull JRootPane rootPane, @NotNull JComponent northComponent) { JPanel panel = new NonOpaquePanel(new BorderLayout()); JPanel tabsContainer = new NonOpaquePanel(new BorderLayout()); tabsContainer.setVisible(false); panel.add(tabsContainer, BorderLayout.NORTH); panel.add(northComponent); rootPane.putClientProperty(WINDOW_TABS_CONTAINER, tabsContainer); rootPane.putClientProperty("Window.transparentTitleBarHeight", 28); return panel; }