Combobox selected same value listener

If I select same item from Combo is there an event to detect it?

This may sound trivial question, but it actually is not. Both value change and selection event are emited only when you select different value.

I do not know what is your exact use case, i.e. why you need this. But there is one thing that could come close to what you need.

There is an extended version of ComboBox in directory that has some additional features called PrefixComboBox

https://vaadin.com/directory/component/prefixcombobox

One of the additional features is PopupClosedEvent that you can add listener for. So this may help you.

Thanks for the answer.
my use case is something like this: in the form is one combobox (for the list choose), and input field (for the generated string from the combobox by id). user select an item from combo and string will be generated to the input field. But after that user can edit input field, if he change an id (from combo), and click the save button than message appear that you cannot change id. after that should be comfortible for user to select again same id from combo and string will be regenerated.