GenericDropdownMenu
GenericDropdownMenu allows you to display contextual menus with default textual options or any VisualElement.
Read time 3 minutesLast updated 4 days ago
Definition
- Type: Class
- Namespace: UnityEngine.UIElements
- Assembly: UnityEngine.UIElementsModule
- Inherits from: AbstractGenericMenu
public class GenericDropdownMenu : AbstractGenericMenu
Remarks
The GenericDropdownMenu is a generic implementation of a dropdown menu that you can use in both Editor UI and runtime UI.
The following example creates a dropdown menu with three items. It displays the menu when the user clicks the button. The example also demonstrates how to set the width of the dropdown menu with the method.
DropDownExamples
using UnityEditor;using UnityEngine;using UnityEngine.UIElements;public class MenuExample : EditorWindow{ [MenuItem("Window/UI Toolkit/MenuExample")] public static void ShowExample() { MenuExample wnd = GetWindow<MenuExample>(); wnd.titleContent = new GUIContent("MenuExample"); } public void CreateGUI() { VisualElement root = rootVisualElement; // Create a button. var button = new Button(); button.text = "Button"; button.style.width = 70; button.RegisterCallback<FocusInEvent>(OnFocusIn); button.RegisterCallback<FocusOutEvent>(OnFocusOut); // Create a dropdown menu with three items. var menu = new GenericDropdownMenu(); menu.AddItem("Item 1", false, a => { Debug.Log("Item 1 was selected"); }, null); menu.AddItem("Item 2", false, a => { Debug.Log("Item 2 was selected"); }, null); menu.AddItem("Item 3 has a very very long label", false, a => { Debug.Log("Item 3 was selected"); }, null); // Return focus to the button when the menu is closed. menu.onClose += () => { button.Focus(); }; // When the button is clicked, the dropdown menu is displayed aligned with the button's world boundaries. button.clicked += () => { // The third and the fourth parameters of the DropDown set the width of the dropdown menu. // This sets the width of the dropdown menu to the width of the container. menu.DropDown(button.worldBound, button, false); // This sets the width of the dropdown menu to the width of the button. // menu.DropDown(button.worldBound, button, true, false); // This sets the width of the dropdown menu to the width of the longest item. // menu.DropDown(button.worldBound, button, true, true); }; root.Add(button); } void OnFocusIn(FocusInEvent evt) { // When the button receives focus, set the background color to a lighter gray. var button = evt.currentTarget as Button; button.style.backgroundColor = Color.dimGray; } void OnFocusOut(FocusOutEvent evt) { // When the button loses focus, return its color to the default color. var button = evt.currentTarget as Button; // Menu also steals focus, but we don't want to reset the color in that case. if (evt.relatedTarget is VisualElement { userData: GenericDropdownMenu menu } && menu.targetElement == button) { return; } button.style.backgroundColor = StyleKeyword.Null; }}
Static Fields
Value | Description |
|---|---|
| checkmarkUssClassName | USS class name of separators in elements of this type. |
| containerInnerUssClassName | USS class name of inner containers in elements of this type. |
| containerOuterUssClassName | USS class name of outer containers in elements of this type. |
| contentWidthUssClassName | USS class name that's added when the GenericDropdownMenu fits the width of its content. |
| itemContentUssClassName | USS class name of labels in elements of this type. |
| itemUssClassName | USS class name of labels in elements of this type. |
| labelUssClassName | USS class name of labels in elements of this type. |
| separatorUssClassName | USS class name of separators in elements of this type. |
| ussClassName | USS class name of elements of this type. |
Constructors
Constructor | Description |
|---|---|
| GenericDropdownMenu() | Initializes and returns an instance of GenericDropdownMenu. |
Properties
Property | Description |
|---|---|
| contentContainer | Returns the content container for the GenericDropdownMenu. Allows users to create their own dropdown menu if they don't want to use the default implementation. It contains a reference to the menu in its _userData. |
| targetElement | Returns the element that determines which root to use as the menu's parent. |
Methods
Method | Description |
|---|---|
| AddDisabledItem | Adds a disabled item to this menu using a default VisualElement. |
| AddItem | Adds an item to this menu using a default VisualElement. |
| AddSeparator | Adds a visual separator after the previously added items in this menu. |
| DropDown | Displays the menu at the specified position. |