Many editable lists share the same type of display component that I call Editable List Combo. It is a combination of there basic Java-based components: a titled pane that contains a button and a drop-down editable list; the button displays the command "Delete". Here is an example:
It is a compact component that displays a list of items and that enable you to remove some items and add some new ones.
To delete an item, select the item to be deleted then click the "Delete" button.
To add a new item, edit any item of the list so that it contains what you want. Press the keyboard key ENTER while the edit cursor is still active in the editable list; the button will display "Add" instead. Click the button, the previous item displayed before editing will not be removed. You can check the list to verify that a new item has been added and none removed.