Version: 2021.3
Language : English
UXML element ScrollView
UXML element Slider

UXML element Scroller

A Scroller lets users scroll through content in your user interface.

Create a Scroller

You can create a Scroller with UI(User Interface) Allows a user to interact with your application. Unity currently supports three UI systems. More info
See in Glossary
Builder, UXML, or C#. The following C# example creates a Scroller with a default value, low limit, and high limit, and sets the direction of the Scroller:

var scroller = new Scroller();
scroller.value = 42;
scroller.lowValue = 0;
scroller.highValue = 100;
scroller.direction = SliderDirection.Vertical;

Example

The following UXML example creates a Scroller:

<UXML xmlns="UnityEngine.UIElements" xmlns:uie="UnityEditor.UIElements">
    <Scroller
        name="the-uxml-scroller"
        direction="Horizontal"
        low-value="0"
        high-value="100" />
</UXML>

The following C# example illustrates some of the customizable functionalities of the Scroller:

/// <sample>
// Get a reference to the scroller from UXML and assign it its value.
var uxmlField = container.Q<Scroller>("the-uxml-scroller");
uxmlField.valueChanged += (v) => {};
uxmlField.value = 42;

// Create a new scroller, disable it, and give it a style class.
var csharpField = new Scroller(0, 100, (v) => {}, SliderDirection.Vertical);
csharpField.SetEnabled(false);
csharpField.AddToClassList("some-styled-scroller");
csharpField.value = uxmlField.value;
container.Add(csharpField);

// Mirror value of uxml scroller into the C# field.
uxmlField.RegisterCallback<ChangeEvent<float>>((evt) =>
{
    csharpField.value = evt.newValue;
});
/// </sample>

To try this example live in Unity, go to Window > UI Toolkit > Samples.

C# base class and namespace

C# class: Scroller
Namespace: UnityEngine.UIElements
Base class: VisualElement

Member attributes

This element has the following member attributes:

Name Type Description
direction UIElements.SliderDirection Direction of this scrollbar.
high-value float Maximum value.
low-value float Minimum value.
value float Value that defines the slider position. It lies between lowValue and highValue.

Inherited attributes

This element inherits the following attributes from its base class:

Name Type Description
focusable boolean True if the element can be focused.
tabindex int An integer used to sort focusables in the focus ring. Must be greater than or equal to zero.

This element also inherits the following attributes from VisualElement:

Name Type Description
content-container string Child elements are added to it, usually this is the same as the element itself.
name string The name of this VisualElement.

Use this property to write USS selectors that target a specific element. The standard practice is to give an element a unique name.
picking-mode UIElements.PickingMode Determines if this element can be pick during mouseEvents or IPanel.Pick queries.
style string Reference to the style object of this element.

Contains data computed from USS files or inline styles written to this object in C#.
tooltip string Text to display inside an information box after the user hovers the element for a small amount of time.
usage-hints UIElements.UsageHints A combination of hint values that specify high-level intended usage patterns for the VisualElement. This property can only be set when the VisualElement is not yet part of a Panel. Once part of a Panel, this property becomes effectively read-only, and attempts to change it will throw an exception. The specification of proper UsageHints drives the system to make better decisions on how to process or accelerate certain operations based on the anticipated usage pattern. Note that those hints do not affect behavioral or visual results, but only affect the overall performance of the panel and the elements within. It’s advised to always consider specifying the proper UsageHints, but keep in mind that some UsageHints might be internally ignored under certain conditions (e.g. due to hardware limitations on the target platform).
view-data-key string Used for view data persistence (ie. tree expanded states, scroll position, zoom level).

This is the key used to save/load the view data from the view data store. Not setting this key will disable persistence for this VisualElement.

USS classes

The following table lists all the C# public property names and their related USS selector.

C# property USS selector Description
ussClassName .unity-scroller USS class name of elements of this type.
horizontalVariantUssClassName .unity-scroller--horizontal USS class name of elements of this type, when they are displayed horizontally.
verticalVariantUssClassName .unity-scroller--vertical USS class name of elements of this type, when they are displayed vertically.
sliderUssClassName .unity-scroller__slider USS class name of slider elements in elements of this type.
lowButtonUssClassName .unity-scroller__low-button USS class name of low buttons in elements of this type.
highButtonUssClassName .unity-scroller__high-button USS class name of high buttons in elements of this type.
disabledUssClassName .unity-disabled USS class name of local disabled elements.

You can also use the Matching Selectors section in the Inspector or the UI Toolkit Debugger to see which USS selectors affect the components of the VisualElement at every level of its hierarchy.

Additional resources

  • ScrollViewA UI Control which displays a large set of Controls in a viewable area that you can see by using a scrollbar. More info
    See in Glossary
UXML element ScrollView
UXML element Slider