Dropdown

Wheel-style dropdown picker that opens a touch-friendly modal list for single-value selection.

Forms forms dropdown combobox select picker

Summary

DropDownControl is a wheel-style dropdown picker that opens from an inline trigger and lets the user confirm a single value from a vertically scrollable modal list.

Typical use cases:

Dial-code or country-code selection before a phone field
Compact selectors that need a touch-friendly modal confirmation step
Any workflow where a finite string list should feel like a native mobile picker rather than a standard menu

Properties

Property	Type	Description
`Items`	`IReadOnlyList<string>`	Ordered values shown in the picker. Updating the list refreshes the trigger label and open list content.
`Value`	`string`	The currently selected value, or an empty string when `Items` is empty.

USS Classes

Class	Description
`dropDownControl`	Root element for the control.
`dropDownControl__trigger`	Closed-state trigger element.
`dropDownControl__triggerLabel`	Label showing the current selection.
`dropDownControl__triggerIcon`	Chevron icon inside the trigger.
`dropDownControl__backdrop`	Full-screen backdrop injected while the picker is open.
`dropDownControl__panel`	Floating modal panel that contains the picker list.
`dropDownControl__viewport`	Clipped viewport used to display the visible rows.
`dropDownControl__list`	Scrolling row container translated by the control logic.
`dropDownControl__row`	A single rendered picker row.
`dropDownControl__selectionLane`	Highlight lane showing the centred selection.
`dropDownControl__fadeTop`	Top fade overlay used to de-emphasize off-centre rows.
`dropDownControl__fadeBottom`	Bottom fade overlay used to de-emphasize off-centre rows.
`dropDownControl--open`	Root modifier applied while the modal picker is visible.

Events

Name	Description	Arguments
`ValueChanged`	Fired after the user confirms a new selection.	`string selectedValue`
`OpenStateChanged`	Fired when the modal picker is opened or closed.	`bool isOpen`

Public Methods

Signature	Description
`SetDefault(string value)`	Sets the selected item when the supplied value exists in `Items`.

Using the Control

using UnityEngine;
using UnityEngine.UIElements;
using UnityUIToolkit.Extensions;

public class DialCodePickerExample : MonoBehaviour
{
    [SerializeField] private UIDocument document;

    private void OnEnable()
    {
        var root = document.rootVisualElement;

        var picker = new DropDownControl
        {
            Items = new[] { "+1", "+33", "+44", "+49" },
        };

        picker.SetDefault("+44");
        picker.ValueChanged += selected => Debug.Log($"Selected {selected}");

        root.Add(picker);
    }
}

Demonstrated In

Dropdown Phone Entry — A phone-number entry form that pairs a country-code dropdown picker with pill input fields.