Version: Unity 6.2 (6000.2)
Language : English
Scroller
SliderInt

Slider

A Slider lets users select a floating-point value from a range of values. You can use a Slider to adjust a value, such as the volume of a sound or the brightness of a light. To set the value, you drag a thumb along a track, or click the track itself. A slider can also include a text input fieldA field that allows the user to input a Text string More info
See in Glossary
, where you can modify the value directly.

Note: To align an element with other fields in an InspectorA Unity window that displays information about the currently selected GameObject, asset or project settings, allowing you to inspect and edit the values. More info
See in Glossary
window, simply apply the .unity-base-field__aligned USS class to it. For more information, refer to BaseField.

Create a Slider

You can create a Slider with UI Builder, UXML, or C#. The following C# example creates a Slider with a default value, low value, and high value, and sets the direction of the slider:

var slider = new Slider();
slider.value = 0.5f;
slider.lowValue = 0;
slider.highValue = 100;
slider.direction = SliderDirection.Horizontal;

Set page size

The Slider control has a page-size property that controls how much the thumb moves, and how much the value changes, when you click the track to either side of the thumb.

If the page size value is 0, clicking the track moves the thumb to the cursor or pointer position, and updates the value accordingly.

If the page size value is greater than 0, clicking the track moves the thumb toward the cursor or pointer position by a specific amount. Slider controls treat page-size as a percentage of the total range.

For example, if the total range is 200, and the page size is 20, then the page size amount is 20% of 200, or 40. Each time you click the track, the thumb moves, and the value increases or decreases by 40.

Keyboard Shortcuts

You can use keyboard shortcuts to navigate and adjust the Slider control. The following table lists the keyboard shortcuts:

Shortcut Action
Arrow Keys Move by 1/100 of the entire range.
Arrow Keys + Shift Move by 1/10 of the entire range.
Home Jump to the start of the slider.
End Jump to the end of the slider.
Page Up Move up by (1/100 of the range) × page size.
Page Down Move down by (1/100 of the range) × page size.

Example

The following UXML example creates a Slider:

<UXML xmlns="UnityEngine.UIElements" xmlns:uie="UnityEditor.UIElements">
    <Slider
        label="UXML Slider"
        name="the-uxml-slider"
        low-value="0"
        high-value="100"
        page-size="1"
        value="42.2" />
</UXML>

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

/// <sample>
// Get a reference to the slider from UXML and assign it its value.
var uxmlSlider = container.Q<Slider>("the-uxml-slider");
uxmlSlider.value = 42.2f;

// Create a new slider, disable it, and give it a style class.
var csharpSlider = new Slider("C# Slider", 0, 100);
csharpSlider.SetEnabled(false);
csharpSlider.AddToClassList("some-styled-slider");
csharpSlider.value = uxmlSlider.value;
container.Add(csharpSlider);

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

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

C# base class and namespace

C# class: Slider
Namespace: UnityEngine.UIElements
Base class: BaseSlider_1

Inherited UXML attributes

This element inherits the following attributes from its base class:

Name Type Description
binding-path string Path of the target property to be bound.
direction UIElements.SliderDirection This is the actual property to contain the direction of the slider.
fill boolean Enables fill to set the color and shape of a slider.
focusable boolean If false, this prevents the element from being focused.

The element can only be focused if its canGrabFocus property is true.
high-value float This is the maximum value that the slider encodes.
inverted boolean This indicates whether or not this slider is inverted. For an inverted horizontal slider, high value is located to the left, low value is located to the right For an inverted vertical slider, high value is located to the bottom, low value is located to the top.
label string The string representing the label that will appear beside the field. If the string is empty, the label element is removed from the hierarchy. If the string is not empty, the label element is added to the hierarchy.
low-value float This is the minimum value that the slider encodes.
page-size float Represents the value that should be applied to the calculated scroll offset while scrolling the slider, such as when clicking within the track or clicking the slider arrows.
show-input-field boolean The visibility of the optional field inside the slider control.

Set this property to true to display a numerical text field that provides another way to edit the slider value.
tabindex int An integer used to sort focusable elements in the focus ring. Must be greater than or equal to zero.

Setting the tabIndex value to less than 0 (for example, −1) removes the element from the focus ring and tab navigation.
value float The actual value of the slider.

This element also inherits the following attributes from VisualElement:

Name Type Description
content-container string Logical container where child elements are added. If a child is added to this element, the child is added to this element’s content container instead.

When iterating over the VisualElement.Children of an element, the element’s content container hierarchy is used instead of the element itself. This can lead to unexpected results, such as elements being ignored by the navigation events if they are not directly in the content container’s hierarchy. Refer to IFocusRing for more information.

If the content container is the same as the element itself, child elements are added directly to the element. This is true for most elements but can be overridden by more complex types.

The ScrollView, for example, has a content container that is different from itself. In that case, child elements added to the scroll view are added to its content container element instead. While the physical parent (VisualElement.Hierarchy.parent) of the child elements is the scroll view’s content container element, their logical parent (VisualElement.parent) still refers to the scroll view itself. Since some of the scroll view’s focusable children are not part of its logical hierarchy, like its Scroller elements, these focusable children are not considered by default when using sequential navigation. Refer to How can I change what element is focused next for an example of a workaround solution if the default navigation rules don’t correspond to your needs.
data-source Object Assigns a data source to this VisualElement which overrides any inherited data source. This data source is inherited by all children.
data-source-path string Path from the data source to the value.
data-source-type System.Type The possible type of data source assignable to this VisualElement.

This information is only used by the UI Builder as a hint to provide some completion to the data source path field when the effective data source cannot be specified at design time.
enabled boolean Returns true if the VisualElement is enabled locally.

This flag isn’t changed if the VisualElement is disabled implicitly by one of its parents. To verify this, use enabledInHierarchy.
language-direction UIElements.LanguageDirection Indicates the directionality of the element’s text. The value will propagate to the element’s children.

Setting languageDirection to RTL can only get the basic RTL support like text reversal. To get more comprehensive RTL support, such as line breaking, word wrapping, or text shaping, you must enable Advance Text Generator.
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 the target of pointer events or picked by IPanel.Pick queries.

Elements can not be picked if:

- They are invisible- Their style.display is set to DisplayStyle.None

Elements with a picking mode of PickingMode.Ignore never receive the hover pseudo-state.
style string Sets the style values on a VisualElement.

The returned style data, computed from USS files or inline styles written to this object in C#, doesn’t represent the fully resolved styles, such as the final height and width of a VisualElement. To access these fully resolved styles, use resolvedStyle.



For information about how to use this property and all the supported USS properties, refer to the Apply styles in C# scripts and USS properties reference manual pages.
tooltip string Text to display inside an information box after the user hovers the element for a small amount of time. This is only supported in the Editor UI.
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, such as tree expanded states, scroll position, or zoom level.

This key is used to save and load the view data from the view data store. If you don’t set this key, the persistence is disabled for the associated VisualElement. For more information, refer to View data persistence in the Unity Manual.

USS classes

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

C# property USS selector Description
ussClassName .unity-slider USS class name of elements of this type.
labelUssClassName .unity-slider__label USS class name of labels in elements of this type.
inputUssClassName .unity-slider__input USS class name of input elements in elements of this type.
ussClassName .unity-base-slider USS class name of elements of this type.
labelUssClassName .unity-base-slider__label USS class name of labels in elements of this type.
inputUssClassName .unity-base-slider__input USS class name of input elements in elements of this type.
horizontalVariantUssClassName .unity-base-slider--horizontal USS class name of elements of this type, when they are displayed horizontally.
verticalVariantUssClassName .unity-base-slider--vertical USS class name of elements of this type, when they are displayed vertically.
dragContainerUssClassName .unity-base-slider__drag-container USS class name of container elements in elements of this type.
trackerUssClassName .unity-base-slider__tracker USS class name of tracker elements in elements of this type.
draggerUssClassName .unity-base-slider__dragger USS class name of dragger elements in elements of this type.
draggerBorderUssClassName .unity-base-slider__dragger-border USS class name of the dragger border element in elements of this type.
fillUssClassName .unity-base-slider__fill USS class name of fill element in elements of this type.
movableUssClassName .unity-base-slider--movable USS class name on the dragger that indicates it is currently controlled by NavigationMoveEvent. When the slider detects move events aligned with the slider’s direction, it adjusts the slider’s value. If it detects a navigation submit event, it removes the style, causing all navigation events to revert to their default behavior. A second navigation submit event re-applies the style to the dragger and restores the previous customized behavior.
ussClassName .unity-base-field USS class name of elements of this type.
labelUssClassName .unity-base-field__label USS class name of labels in elements of this type.
inputUssClassName .unity-base-field__input USS class name of input elements in elements of this type.
noLabelVariantUssClassName .unity-base-field--no-label USS class name of elements of this type, when there is no label.
labelDraggerVariantUssClassName .unity-base-field__label--with-dragger USS class name of labels in elements of this type, when there is a dragger attached on them.
mixedValueLabelUssClassName .unity-base-field__label--mixed-value USS class name of elements that show mixed values
alignedFieldUssClassName .unity-base-field__aligned USS class name of elements that are aligned in a inspector element
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

Scroller
SliderInt