The ui5-combobox provides advanced keyboard handling.
[F4], [Alt]+[Up], or [Alt]+[Down] - Toggles the picker.
[Escape] - Closes the picker, if open. If closed, cancels changes and reverts the typed in value.
[Enter] or [Return] - If picker is open, takes over the currently selected item and closes it.
[Down] - Selects the next matching item in the picker.
[Up] - Selects the previous matching item in the picker.
[Page Down] - Moves selection down by page size (10 items by default).
[Page Up] - Moves selection up by page size (10 items by default).
[Home] - If focus is in the ComboBox, moves cursor at the beginning of text. If focus is in the picker, selects the first item.
[End] - If focus is in the ComboBox, moves cursor at the end of text. If focus is in the picker, selects the last item.
[Ctrl]+[Alt]+[F8] or [Command]+[Option]+[F8] - Focuses the first link in the value state message, if available. Pressing [Tab] moves the focus to the next link in the value state message, or closes the value state message if there are no more links.
Determines the name by which the component will be identified upon submission in an HTML form. Note: This property is only applicable within the context of an HTML Form element.
Defines the value state message that will be displayed as pop up under the component. The value state message slot should contain only one root element. Note: If not specified, a default text (in the respective language) will be displayed. Note: The valueStateMessage would be displayed, when the ui5-combobox is in Information, Critical or Negative value state.