Use the contextual menu events, ContextualMenuManipulator
and ContextualMenuPopulateEvent
, to display a set of choices when a user performs certain actions, such as when a user right-clicks a label.
To enable contextual menus, attach the ContextualMenuManipulator
to a visual elementA node of a visual tree that instantiates or derives from the C# VisualElement
class. You can style the look, define the behaviour, and display it on screen as part of the UI. More info
See in Glossary. This manipulator displays a contextual menu after either a right button mouse up event or a menu key up event. The ContextualMenuManipulator
manipulator also adds a callback that responds to a ContextualMenuPopulateEvent
.
The following code example adds a contextual menu to a visual element. The menu has only one item.
void InstallManipulator(VisualElement element) { ContextualMenuManipulator m = new ContextualMenuManipulator(MyDelegate); m.target = element; } void MyDelegate(ContextualMenuPopulateEvent event) { // Modify event.menu event.menu.AppendAction("My action", DisplayProperties, DropdownMenu.MenuAction.AlwaysEnabled); } void DisplayProperties(DropdownMenu.MenuAction menuItem) { // ... }
The callback given to the ContextualMenuManipulator
constructor is invoked last so child elements can populate the menu.
The manipulator sends a ContextualMenuPopulateEvent
event propagated to the target element hierarchy. The event moves along the propagation path: from the root of the visual treeAn object graph, made of lightweight nodes, that holds all the elements in a window or panel. It defines every UI you build with the UI Toolkit.
See in Glossary to the event target, and then back up the visual tree to the root. Along the propagation path, the elements with a callback for the ContextualMenuPopulateEvent
event can add, remove, or update items in the contextual menu.
When an element receives a ContextualMenuPopulateEvent
, it calls either DropdownMenu.InsertAction()
or DropdownMenu.AppendAction()
to add menu items to the contextual menu.
DropdownMenu.InsertAction()
and DropdownMenu.AppendAction()
take two callbacks as parameters. The first callback executes when the user selects the item in the menu. The second callback executes before it displays the menu and also checks whether the menu item is enabled.
Both callbacks receive a MenuAction
as a parameter. The MenuAction
represents the menu item and has the following properties:
MenuAction.userData
includes a reference to user data used with AppendAction()
or InsertAction()
.MenuAction.eventInfo
includes information about the event that displays the contextual menu. Use MenuAction.eventInfo
in the action that responds to the event. For example, you can use the mouse position to create and place an object based on the selected contextual menu item.The following example creates a custom Editor window with two labels and adds contextual menus for each label. The example demonstrates how to add, remove, and update a contextual menu.
Create a Unity project with any template.
In the Project windowA window that shows the contents of your Assets
folder (Project tab) More info
See in Glossary, create a folder named Editor
.
In the Editor
window, create a C# script named ContextualMenuDemo
and replace its contents with the following:
using UnityEditor; using UnityEngine; using UnityEngine.UIElements; public class ContextualMenuDemo : EditorWindow { [MenuItem("Window/ContextualMenuDemo")] public static void ShowExample() { ContextualMenuDemo wnd = GetWindow<ContextualMenuDemo>(); wnd.titleContent = new GUIContent("ContextualMenuDemo"); } public void CreateGUI() { VisualElement root = rootVisualElement; VisualElement label = new Label("Right click me!"); root.Add(label); AddANewContextMenu(label); InsertIntoAnExistingMenu(label); VisualElement second = new Label("Click me also!"); root.Add(second); AddANewContextMenu(second); InsertIntoAnExistingMenu(second); // Override the default behavior by clearing the menu. ReplaceContextMenu(second); } void AddANewContextMenu(VisualElement element) { // The manipulator handles the right click and sends a ContextualMenuPopulateEvent to the target element. // The callback argument passed to the constructor is automatically registered on the target element. element.AddManipulator(new ContextualMenuManipulator((evt) => { evt.menu.AppendAction("First menu item", (x) => Debug.Log("First!!!!"), DropdownMenuAction.AlwaysEnabled); evt.menu.AppendAction("Second menu item", (x) => Debug.Log("Second!!!!"), DropdownMenuAction.AlwaysEnabled); })); } void InsertIntoAnExistingMenu(VisualElement element) { element.RegisterCallback<ContextualMenuPopulateEvent>((evt) => { evt.menu.AppendSeparator(); evt.menu.AppendAction("Another action", (x) => Debug.Log("Another Action!!!!"), DropdownMenuAction.AlwaysEnabled); }); } void ReplaceContextMenu(VisualElement element) { element.RegisterCallback<ContextualMenuPopulateEvent>((evt) => { evt.menu.ClearItems(); evt.menu.AppendAction("The only action", (x) => Debug.Log("The only action!"), DropdownMenuAction.AlwaysEnabled); }); } }
To see the example live, from the menu, select Window > UI Toolkit > ContextualMenuDemo.
Did you find this page useful? Please give it a rating:
Thanks for rating this page!
What kind of problem would you like to report?
Thanks for letting us know! This page has been marked for review based on your feedback.
If you have time, you can provide more information to help us fix the problem faster.
Provide more information
You've told us this page needs code samples. If you'd like to help us further, you could provide a code sample, or tell us about what kind of code sample you'd like to see:
You've told us there are code samples on this page which don't work. If you know how to fix it, or have something better we could use instead, please let us know:
You've told us there is information missing from this page. Please tell us more about what's missing:
You've told us there is incorrect information on this page. If you know what we should change to make it correct, please tell us:
You've told us this page has unclear or confusing information. Please tell us more about what you found unclear or confusing, or let us know how we could make it clearer:
You've told us there is a spelling or grammar error on this page. Please tell us what's wrong:
You've told us this page has a problem. Please tell us more about what's wrong:
Thank you for helping to make the Unity documentation better!
Your feedback has been submitted as a ticket for our documentation team to review.
We are not able to reply to every ticket submitted.
When you visit any website, it may store or retrieve information on your browser, mostly in the form of cookies. This information might be about you, your preferences or your device and is mostly used to make the site work as you expect it to. The information does not usually directly identify you, but it can give you a more personalized web experience. Because we respect your right to privacy, you can choose not to allow some types of cookies. Click on the different category headings to find out more and change our default settings. However, blocking some types of cookies may impact your experience of the site and the services we are able to offer.
More information
These cookies enable the website to provide enhanced functionality and personalisation. They may be set by us or by third party providers whose services we have added to our pages. If you do not allow these cookies then some or all of these services may not function properly.
These cookies allow us to count visits and traffic sources so we can measure and improve the performance of our site. They help us to know which pages are the most and least popular and see how visitors move around the site. All information these cookies collect is aggregated and therefore anonymous. If you do not allow these cookies we will not know when you have visited our site, and will not be able to monitor its performance.
These cookies may be set through our site by our advertising partners. They may be used by those companies to build a profile of your interests and show you relevant adverts on other sites. They do not store directly personal information, but are based on uniquely identifying your browser and internet device. If you do not allow these cookies, you will experience less targeted advertising. Some 3rd party video providers do not allow video views without targeting cookies. If you are experiencing difficulty viewing a video, you will need to set your cookie preferences for targeting to yes if you wish to view videos from these providers. Unity does not control this.
These cookies are necessary for the website to function and cannot be switched off in our systems. They are usually only set in response to actions made by you which amount to a request for services, such as setting your privacy preferences, logging in or filling in forms. You can set your browser to block or alert you about these cookies, but some parts of the site will not then work. These cookies do not store any personally identifiable information.