void (Runnable contentAction) { if (myContents.size() == 0) { myPlaceholder.removeAll(); myTabs.removeAllTabs(); if (myPopup != null) { myPopup.cancel(); myPopup = null; } } else { if (myPlaceholder.isNull()) { myPlaceholder.setContent(myTabs.getComponent()); } contentAction.run(); } restoreProportions(); myTabs.getComponent().revalidate(); myTabs.getComponent().repaint(); }