material-components_material-components-android/docs/components/Slider.md

Slider

Sliders allow users to make selections from a range of values.

Contents

• Using sliders
• Continuous slider
• Discrete slider
• Theming sliders

Using sliders

Before you can use Material sliders, you need to add a dependency to the Material Components for Android library. For more information, go to the Getting started page.

Usage

A Slider can be added in a layout like so:

<!-- Continuous slider -->
<com.google.android.material.slider.Slider
    ...
    android:valueFrom="0.0"
    android:valueTo="100.0"  />

<!-- Discrete slider -->
<com.google.android.material.slider.Slider
    ...
    android:valueFrom="0.0"
    android:valueTo="100.0"
    android:stepSize="10.0"  />

Changes to a slider can be observed like so:

slider.addOnSliderTouchListener(object : Slider.OnSliderTouchListener {
    override fun onStartTrackingTouch(slider: Slider) {
        // Responds to when slider's touch event is being started
    }

    override fun onStopTrackingTouch(slider: Slider) {
        // Responds to when slider's touch event is being stopped
    }
})

slider.addOnChangeListener { slider, value, fromUser ->
    // Responds to when slider's value is changed
}

Similarly, a RangeSlider can be added in a layout like so:

<!-- Continuous slider -->
<com.google.android.material.slider.RangeSlider
    ...
    android:valueFrom="0.0"
    android:valueTo="100.0"
    app:values="@array/initial_values"  />

<!-- Discrete slider -->
<com.google.android.material.slider.RangeSlider
    ...
    android:valueFrom="0.0"
    android:valueTo="100.0"
    app:values="@array/initial_slider_values"
    android:stepSize="10.0"  />

And in values/arrays.xml:

<resources>
  <array name="initial_slider_values">
    <item>20.0</item>
    <item>70.0</item>
  </array>
</resources>

Changes to a range slider can be observed like so:

rangeSlider.addOnSliderTouchListener(object : RangeSlider.OnSliderTouchListener {
    override fun onStartTrackingTouch(slider: RangeSlider) {
        // Responds to when slider's touch event is being started
    }

    override fun onStopTrackingTouch(slider: RangeSlider) {
        // Responds to when slider's touch event is being stopped
    }
})

rangeSlider.addOnChangeListener { rangeSlider, value, fromUser ->
    // Responds to when slider's value is changed
}

Making sliders accessible

Sliders support setting content descriptors for use with screen readers. While optional, we strongly encourage their use.

That can be done in XML via the android:contentDescription attribute or programmatically like so:

slider.contentDescription = contentDescription

Additionaly, if using a TextView to display the value of the slider, you should set android:labelFor on it, so that screen readers announce that TextView refers to the slider.

Adding/removing the value label

By default, the slider will show a value label above the thumb when it's selected. You can change how it's drawn via the app:labelBehavior attribute or setLabelBehavior method.

The modes of app:labelBehavior are:

• floating (default) - draws the label floating above the bounds of this view
• withinBounds - draws the label floating within the bounds of this view
• gone - prevents the label from being drawn

Setting a LabelFormatter

By using a LabelFormatter you can display the selected value using letters to indicate magnitude (e.g.: 1.5K, 3M, 12B). That can be achieved through the setLabelFormatter method.

The following example shows a slider for a prince range in the USD currency.

In code:

rangeSlider.setLabelFormatter { value: Float ->
    val format = NumberFormat.getCurrencyInstance()
    format.maximumFractionDigits = 0
    format.currency = Currency.getInstance("USD")
    format.format(value.toDouble())
}

Types

There are two types of sliders: 1. Continuous slider, 2. Discrete slider

A slider with two thumbs is called a range slider.

Continuous slider

Continuous sliders allow users to make meaningful selections that don’t require a specific value.

API and source code:

• Slider
  • Class definition
  • Class source

The following example shows a continuous slider.

In the layout:

<com.google.android.material.slider.Slider
    android:id="@+id/slider"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:contentDescription="@string/slider_desc"
    android:value="20.0"
    android:valueFrom="0.0"
    android:valueTo="100.0" />

Continuous range slider

API and source code:

• RangeSlider
  • Class definition
  • Class source

The following example shows a continuous range slider.

In the layout:

<com.google.android.material.slider.RangeSlider
  android:id="@+id/range_slider"
  android:layout_width="match_parent"
  android:layout_height="wrap_content"
  android:contentDescription="@string/slider_desc"
  app:values="@array/initial_slider_values"
  android:valueFrom="0.0"
  android:valueTo="100.0" />

Discrete slider

Discrete sliders display a numeric value label upon pressing the thumb, which allows a user to input an exact value.

API and source code:

• Slider
  • Class definition
  • Class source

The following example shows a discrete slider.

In the layout:

<com.google.android.material.slider.Slider
    ...
    android:stepSize="5.0" />

Discrete range slider

API and source code:

• RangeSlider
  • Class definition
  • Class source

The following example shows a discrete range slider.

In the layout:

<com.google.android.material.slider.RangeSlider
    ...
    android:stepSize="5.0"  />

Anatomy and key properties

A slider has a track, one or two thumbs, and optional value label. A discrete slider also has tick marks.

1. Track
2. Thumb
3. Value label (optional)
4. Tick mark (discrete sliders)

Track attributes

	Attribute	Related method(s)	Default value
Min value	android:valueFrom	setValueFrom getValueFrom	N/A
Max value	android:valueTo	setValueTo getValueTo	N/A
Step size (discrete)	android:stepSize	setStepSize getStepSize	N/A
Initial selected value (Slider)	android:value	setValue getValue	N/A
Initial selected values (RangeSlider)	app:values	setValues getValues	N/A
Height	app:trackHeight	setTrackHeight getTrackHeight	4dp
Color	app:trackColor	setTrackTintList getTrackTintList	null
Color for track's active part	app:trackColorActive	setTrackActiveTintList getTrackActiveTintList	?attr/colorPrimary
Color for track's inactive part	app:trackColorInactive	setTrackInactiveTintList getTrackInactiveTintList	?attr/colorPrimary at 24%
Minimum separation for adjacent thumbs	app:minSeparation	setMinSeparation getMinSeparation	0dp

Note: app:trackColor takes precedence over app:trackColorActive and app:trackColorInative. It's a shorthand for setting both values to the same thing.

Thumb attributes

	Attribute	Related method(s)	Default value
Color	app:thumbColor	setThumbTintList getThumbTintList	?attr/colorPrimary
Radius	app:thumbRadius	setThumbRadiusResource setThumbRadius getThumbRadius	10dp
Elevation	app:thumbElevation	setThumbElevationResource setThumbElevation getThumbElevation	1dp
Halo color	app:haloColor	setHaloTintList getHaloTintList	?attr/colorPrimary at 24%
Halo radius	app:haloRadius	setHaloRadiusResource setHaloRadius getHaloRadius	24dp
Stroke color	app:thumbStrokeColor	setThumbStrokeColor setThumbStrokeColorResource getThumbStrokeColor	null
Stroke width	app:thumbStrokeWidth	setThumbStrokeWidth setThumbStrokeWidthResource getThumbStrokeWidth	0dp

Value label attributes

	Attribute	Related method(s)	Default value
Style	app:labelStyle	N/A	@style/Widget.MaterialComponents.Tooltip
Formatter	N/A	setLabelFormatter hasLabelFormatter	null
Behavior	app:labelBehavior	setLabelBehavior getLabelBehavior	floating

Note: The value label is a Tooltip.

Tick mark attributes

	Attribute	Related method(s)	Default value
Color	app:tickColor	setTickTintList getTickTintList	null
Color for track's active part	app:tickColorActive	setTickActiveTintList getTickActiveTintList	?attr/colorOnPrimary at 54%
Color for track's inactive part	app:tickColorInactive	setTickInactiveTintList getTickInactiveTintList	?attr/colorPrimary at 54%
Tick visible	app:tickVisible	setTickVisible isTickVisible()	true

Note: app:tickColor takes precedence over app:tickColorActive and app:tickColorInative. It's a shorthand for setting both values to the same thing.

Styles

	Style
Default style	Widget.MaterialComponents.Slider

Default style theme attribute: ?attr/sliderStyle

See the full list of styles and attributes.

Theming sliders

Sliders support Material Theming and can be customized in terms of color and typography.

Slider theming example

API and source code:

• Slider
  • Class definition
  • Class source
• RangeSlider
  • Class definition
  • Class source

The following example shows a range slider with Material Theming.

Implementing slider theming

Using theme attributes and styles in res/values/styles.xml (themes all sliders and affects other components):

<style name="Theme.App" parent="Theme.MaterialComponents.*">
    ...
    <item name="colorPrimary">@color/shrine_pink_100</item>
    <item name="colorOnPrimary">@color/shrine_pink_900</item>
    <item name="colorOnSurface">@color/shrine_pink_100</item>
</style>

or using a default style theme attribute, styles and a theme overlay (themes all sliders but does not affect other components):

<style name="Theme.App" parent="Theme.MaterialComponents.*">
    ...
    <item name="sliderStyle">@style/Widget.App.Slider</item>
</style>

<style name="Widget.App.Slider" parent="Widget.MaterialComponents.Slider">
    <item name="materialThemeOverlay">@style/ThemeOverlay.App.Slider</item>
    <item name="labelStyle">@style/Widget.App.Tooltip</item>
  </style>

<style name="ThemeOverlay.App.Slider" parent="">
    <item name="colorPrimary">@color/shrine_pink_100</item>
    <item name="colorOnPrimary">@color/shrine_pink_900</item>
    <item name="colorOnSurface">@color/shrine_pink_100</item>
</style>

<style name="Widget.App.Tooltip" parent="Widget.MaterialComponents.Tooltip">
    <item name="android:textAppearance">@style/TextAppearance.App.Tooltip</item>
    <item name="backgroundTint">@color/shrine_pink_900</item>
  </style>

<style name="TextAppearance.App.Tooltip" parent="TextAppearance.MaterialComponents.Tooltip">
  <item name="android:textColor">@color/shrine_pink_100</item>
  <item name="fontFamily">@font/rubik</item>
  <item name="android:fontFamily">@font/rubik</item>
</style>

or using the style in the layout (affects only this specific slider):

<com.google.android.material.slider.RangeSlider
    ...
    style="@style/Widget.App.Slider"  />