Set heavyweight tooltip popups for any component in Swing.

ComponentUtils.java

public final class ComponentUtils {
    
    private ComponentUtils() { }
    
    public static void forceHeavyWeightPopups(JComponent component) {
        try {
            Class<?> clazz = Class.forName("javax.swing.ClientPropertyKey");
            Field field = clazz.getDeclaredField("PopupFactory_FORCE_HEAVYWEIGHT_POPUP");
            field.setAccessible(true);
            component.putClientProperty(field.get(null), Boolean.TRUE);
        } catch (ClassNotFoundException | IllegalAccessException | IllegalArgumentException | NoSuchFieldException | SecurityException e) {
            throw new RuntimeException("Couldn't force heavyweight popups on component: " + component, e);
        }
    }
}