VisualElementReference

Description

Represents a reference to a VisualElement in a PanelRenderer.

This example shows how to use VisualElementReference to reference an element in a UXML file that is loaded by a <see cref="PanelRenderer" />.

using UnityEngine;
using UnityEngine.UIElements;

public class VisualElementReference_Example : MonoBehaviour
{
    // Set via the inspector
    public VisualElementReference elementReference = new VisualElementReference();
    public Color customColor = Color.red;

    void Start()
    {
        elementReference.RegisterReferenceResolvedCallback(SetupButton);
    }

    void SetupButton(VisualElement ve)
    {
        ve.style.backgroundColor = customColor;
    }
}

The following example configures paths to reference elements in a nested UXML structure. Root UXML:

<ui:UXML xmlns:ui="UnityEngine.UIElements" editor-extension-mode="False">
    <ui:Template name="VisualElementReference_ExampleTemplate" src="./VisualElementReference_ExampleTemplate.uxml"/>
    <ui:VisualElement name="my-element" authoring-id="123"/>
    <ui:Button text="Button" name="my-button" authoring-id="-5"/>
    <ui:Instance template="VisualElementReference_ExampleTemplate" name="instance1" authoring-id="1"/>
    <ui:Instance template="VisualElementReference_ExampleTemplate" name="instance2" authoring-id="2"/>
</ui:UXML>

Template UXML:

<ui:UXML xmlns:ui="UnityEngine.UIElements" editor-extension-mode="False">
    <ui:VisualElement name="template-element" authoring-id="1"/>
    <ui:Button text="Button" name="template-button" authoring-id="101"/>
</ui:UXML>

using UnityEngine;
using UnityEngine.UIElements;

public class VisualElementReference_ExampleNested : MonoBehaviour
{
    public VisualElementReference<Button> templateInstance1Button = new VisualElementReference<Button>();
    public VisualElementReference elementReference = new VisualElementReference();

    void Start()
    {
        var pr = GetComponent<PanelRenderer>();

        // 101 is the AuthoringId of the Button inside the template instance with AuthoringId 1
        templateInstance1Button.SetReference(pr, new AuthoringIdPath(1, 101));
        templateInstance1Button.RegisterReferenceResolvedCallback(SetupButtonReference);
        templateInstance1Button.RegisterReferenceUnloadedCallback(TeardownButtonReference);

        // 123 is the AuthoringId of a VisualElement in the root UXML file
        elementReference.SetReference(pr, new AuthoringIdPath(123));
        elementReference.RegisterReferenceResolvedCallback(SetupElementReference);
    }

    void SetupButtonReference(Button button)
    {
        button.clicked += OnButtonClick;
    }

    void TeardownButtonReference(Button button)
    {
        button.clicked -= OnButtonClick;
    }

    void OnButtonClick()
    {
        Debug.Log("Button inside template instance clicked!");
    }

    void SetupElementReference(VisualElement ve)
    {
        ve.Add(new Label { text = "Element Reference Resolved!" });
    }
}

Properties

Constructors

Public Methods