void (@NotNull ContentManager contentManager) { reset(); idLabel = new BaseLabel(ui, ExperimentalUI.isNewUI()) { @Override protected boolean allowEngravement() { return myUi.window.isActive(); } }; dropOverPlaceholder = new JLabel() { @Override public void paint(Graphics g) { g.setColor(JBUI.CurrentTheme.DragAndDrop.Area.BACKGROUND); RectanglePainter.FILL.paint((Graphics2D)g, 0, 0, getWidth(), getHeight(), null); } @Override public Dimension getPreferredSize() { return new Dimension(TabContentLayout.this.ui.dropOverWidth, 1); } }; MouseDragHelper.setComponentDraggable(idLabel, true); for (int i = 0; i < contentManager.getContentCount(); i++) { contentAdded(new ContentManagerEvent(this, contentManager.getContent(i), i)); } }