void setFilter( Predicate<Item> filter ) {
			this.filter = filter;

			if( filter != null ) {
				ArrayList<Item> list = new ArrayList<>( allItems.length );
				for( Item item : allItems ) {
					if( filter.test( item ) )
						list.add( item );
				}
				items = list.toArray( new Item[list.size()] );
			} else
				items = allItems;

			fireTableDataChanged();
		}
Creates a UI defaults inspector panel that can be embedded into any window.
flatlaf-extras/src/main/java/com/formdev/flatlaf/extras/FlatUIDefaultsInspector.java