Dropdown

Popup options selector with optional search filtering. Displays a scrollable list of options with auto-direction detection.

Inspector Setup

Add AutoLayout Dropdown to a GameObject with AutoLayout.
Populate the Options list in the Inspector.
Configure appearance and behavior settings.

Field	Type	Default	Description
Options	List<string>	-	List of option strings
Selected Index	int	-1	Currently selected option index
Popup Max Height	float	400	Maximum popup height in pixels
Item Height	float	48	Height of each option item
Direction	DropdownDirection	Auto	Popup direction: Auto, Up, or Down
Searchable	bool	false	Show search/filter field

Code Usage

AutoUI Builder

// Basic dropdown — set sizing on the parent before calling .Dropdown()
AutoUI.Create()
    .Width(280).Height(40)
    .Dropdown()
        .Options(new[] { "Option A", "Option B", "Option C" })
        .DefaultIndex(0)
        .PopupMaxHeight(300)
        .OnValueChanged(index => Debug.Log($"Selected: {index}"))
        .Capture(dd => m_Dropdown = dd)
    .End()
    .Build();

// Searchable dropdown
AutoUI.Create()
    .WidthFill().Height(48)
    .Dropdown()
        .Options(countriesList)
        .DefaultIndex(0)
        .PopupMaxHeight(400)
        .Searchable()
        .OnValueChanged(OnCountryChanged)
        .Capture(dd => m_SearchDropdown = dd)
    .End()
    .Build();

Sizing note: .Dropdown() configures the parent as a Row with CrossAlign(Center) (the layout the dropdown header needs), but does not set Width/Height/Padding — those are your call. Set them on the parent before the .Dropdown() call.

Programmatic Control

// Update options at runtime
m_Dropdown.Options = new List<string> { "New A", "New B", "New C" };

// Change selection
m_Dropdown.SelectedIndex = 1;

// Read selection
string selected = m_Dropdown.SelectedText;
int index = m_Dropdown.SelectedIndex;

// Toggle popup
m_Dropdown.Toggle();
m_Dropdown.Show();
m_Dropdown.Hide();

Methods

Method	Description
`Toggle()`	Open or close the popup
`Show()`	Open the popup
`Hide()`	Close the popup

Properties

Property	Type	Description
`SelectedIndex`	int	Get/set selected option index
`SelectedText`	string	Get the selected option text
`IsOpen`	bool	Whether popup is visible
`Options`	List<string>	Get/set options list
`PopupMaxHeight`	float	Maximum popup height
`ItemHeight`	float	Per-item height
`Direction`	DropdownDirection	Popup direction
`Searchable`	bool	Search field enabled

Events

Event	Signature	Description
`OnValueChanged`	`Action<int>`	Fires when selection changes

Callbacks

Callback	Signature	Description
`BindItemCallback`	`Action<GameObject, int, bool>`	Custom item rendering (go, index, isSelected)
`UnbindItemCallback`	`Action<GameObject, int>`	Cleanup on item recycle

Builder API

Method	Description
`.Options(string[])` / `.Options(List<string>)`	Set option strings
`.DefaultIndex(int)`	Set initial selection
`.PopupMaxHeight(float)`	Set max popup height
`.ItemHeight(float)`	Set item height
`.Direction(DropdownDirection)`	Set popup direction
`.Searchable()`	Enable search field
`.OnValueChanged(Action<int>)`	Subscribe to selection changes
`.Capture(Action<AutoLayoutDropdown>)`	Capture component reference
`.End()`	Return to parent LayoutBuilder

Notes

Direction = Auto measures available space above/below and picks the best direction.
The popup is created in an overlay layer so it renders above other UI.
Search filtering is case-insensitive substring matching.