filtering rows in vaadin8 grid

Hi, I’m trying to make filter in grid’s column with combobox (combobox is used to select appopriate value).
Is there any way to get Set of displayed column’s items in grid? The idea is to change list of items in combobox depending on the grid’s filterable column data.

There is indeed change of logic between Vaadin 7 and 8 here. In Vaadin 7, the Container.getItemIds() returns list of itemIds after filtering. In Vaadin 8, the ListDataProvider.getItems() returns raw data source list without applying filter. You need to use ListDataProvider.fetch(…) method instead. It returns Stream of items after applying the filters. This I guess has been done inorder to utilize more Java 8 conventions.

Thanks! fetch works fine, But I need to get a Collection of some column only.
For example if we have a Grid with columns: id, name, age - I want to get a Collection of all names.
I’ll try to use Reflection to write method like this:
Set getUnic(String columnid)