Slider

Since 2.2.33

Slider selects a float in a [min, max] range. It is the value-picking counterpart to Scroller: its handle has a fixed size, while a scroller handle represents viewport size. Two concrete variants are registered:

• slider-horizontal — horizontal slider, 7 px high by default.
• slider-vertical — vertical slider, 7 px wide by default.

Dragging the handle, left-clicking the track, or using the mouse wheel changes the value. Slider extends BindableUIElement<Float>, so it can use normal data bindings.

Horizontal and vertical variants rendered in the client. The filled track shows the current value; the square is the draggable handle.

INFO

Everything documented on UIElement applies here too: layout, styles, events, and data bindings.

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Usage

var volume = new Slider.Horizontal()
        .setRange(0f, 100f)
        .setValue(40f)
        .setOnValueChanged(value -> saveVolume(value));
volume.sliderStyle(style -> style.sliderStep(0.05f));
parent.addChild(volume);

var vertical = new Slider.Vertical().setRange(-1f, 1f);

let slider = new SliderHorizontal();
slider.setRange(0, 100);
slider.setValue(40);
slider.setOnValueChanged(value => saveVolume(value));
parent.addChild(slider);

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XML

<slider-horizontal min-value="0" max-value="100" value="40"/>
<slider-vertical min-value="-1" max-value="1" value="0"/>

XML attribute	Type	Description
min-value	float	Minimum value. Default: 0.
max-value	float	Maximum value. Default: 1.
value	float	Initial value. Default: 0.

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Internal Structure

Field	CSS class	Description
trackContainer	.__slider_track_container__	Full hit area; receives track clicks and wheel events.
track	.__slider_track__	The thin background line.
fill	.__slider_fill__	Filled line from minimum to the current value.
handle	.__slider_handle__	Fixed-size draggable Button.

---

Slider Style

INFO

slider-step

Fraction of the full range moved by one mouse-wheel notch. Default: 0.1.

slider.sliderStyle(style -> style.sliderStep(0.05f));

slider-horizontal { slider-step: 0.05; }

INFO

slider-track-size

Track thickness in pixels. Default: 1.

slider.sliderStyle(style -> style.trackSize(2));

slider-horizontal { slider-track-size: 2; }

INFO

slider-handle-size

Handle length along the track in pixels. Default: 3.

slider.sliderStyle(style -> style.handleSize(6));

slider-horizontal { slider-handle-size: 6; }

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Value Binding

slider.bind(DataBindingBuilder.floatVal(
        () -> state.getVolume(),
        value -> state.setVolume(value)
).build());

See Data Bindings for sync strategies and lifecycle rules.

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Fields

Name	Type	Access	Description
trackContainer	UIElement	public final	Full slider hit area.
track	UIElement	public final	Background line.
fill	UIElement	public final	Filled value line.
handle	Button	public final	Draggable handle.
sliderStyle	SliderStyle	private (getter)	Current slider style.
minValue / maxValue	float	protected (getter)	Current range endpoints.
isDragging	boolean	protected (getter)	true while dragging the handle.

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Methods

Method	Returns	Description
setRange(float, float)	Slider	Sets the range and clamps the current value.
setMinValue(float) / setMaxValue(float)	Slider	Changes one range endpoint.
setValue(Float)	Slider	Sets the clamped value and notifies listeners.
setValue(Float, boolean)	Slider	Sets the value; pass false to suppress notification.
setNormalizedValue(float)	Slider	Sets a normalized 0..1 position.
getNormalizedValue()	float	Gets the normalized position.
slideValue(float)	void	Moves by a normalized range fraction.
setOnValueChanged(FloatConsumer)	Slider	Registers a value listener.
sliderStyle(Consumer<SliderStyle>)	Slider	Configures style fluently.
trackContainer(...), track(...), fill(...), handle(...)	Slider	Configures internal elements.