RadioButton.md

Selection controls: radio buttons

Selection controls allow the user to select options.

Use radio buttons to:

• Select a single option from a list
• Expose all available options
• If available options can be collapsed, consider using a dropdown menu instead, as it uses less space.

Contents

• Using radio buttons
• Radio button
• Theming radio buttons

Using radio buttons

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

Note: <RadioButton> is auto-inflated as <com.google.android.material.button.MaterialRadioButton> via MaterialComponentsViewInflater when using a non-Bridge Theme.MaterialComponents.* theme.

Making radio buttons accessible

Radio buttons support content labeling for accessibility and are readable by most screen readers, such as TalkBack. Text rendered in radio buttons is automatically provided to accessibility services. Additional content labels are usually unnecessary.

Grouping radio buttons

Changes in the states of one radio button can affect other buttons in the group. Specifically, selecting a RadioButton in a RadioGroup will de-select all other buttons in that group. See the example section below for implementation details.

Radio button

A radio button is a circle that is filled in with an inset when selected. Radio buttons allow the user to select one option from a set. Use radio buttons when the user needs to see all available options. If available options can be collapsed, consider using a dropdown menu because it uses less space.

Radio buttons example

API and source code:

• MaterialRadioButton
  • Class definition
  • Class source
• RadioGroup
  • Class definition

The following example shows a radio button group with five radio buttons.

In the layout:

<RadioGroup
    android:id="@+id/radioGroup"
    android:checkedButton="@+id/radio_button_1"
    android:layout_width="match_parent"
    android:layout_height="wrap_content">
    <RadioButton
        android:id="@+id/radio_button_1"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:text="@string/label_1"/>
    <RadioButton
        android:id="@+id/radio_button_2"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:text="@string/label_2"/>
    <RadioButton
        android:id="@+id/radio_button_3"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:text="@string/label_3"/>
    <RadioButton
        android:id="@+id/radio_button_4"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:text="@string/label_4"/>
    <RadioButton
        android:id="@+id/radio_button_5"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:enabled="false"
        android:text="@string/label_5"/>
</RadioGroup>

In code:

val checkedRadioButtonId = radioGroup.checkedRadioButtonId // Returns View.NO_ID if nothing is checked.
radioGroup.setOnCheckedChangeListener { group, checkedId ->
    // Responds to child RadioButton checked/unchecked
}

// To check a radio button
radioButton.isChecked = true

// To listen for a radio button's checked/unchecked state changes
radioButton.setOnCheckedChangeListener { buttonView, isChecked
    // Responds to radio button being checked/unchecked
}

Key properties

Radio button attributes

Element	Attribute	Related method(s)	Default value
To use material colors	app:useMaterialThemeColors	setUseMaterialThemeColors isUseMaterialThemeColors	true (ignored if app:buttonTint is set)
Color	app:buttonTint	setButtonTintList getButtonTintList	null
Min size	android:minWidth android:minHeight	(set/get)MinWidth (set/get)MinHeight	?attr/minTouchTargetSize

The color of the radio button defaults to ?attr/colorOnSurface (unchecked) and ?attr/colorSecondary (checked) defined in your app theme. If you want to override this behavior, as you might with a custom drawable that should not be tinted, set app:useMaterialThemeColors to false:

<RadioButton
        ...
    app:useMaterialThemeColors="false"
    />

Text label attributes

Element	Attribute	Related method(s)	Default value
Text label	android:text	setText getText	null
Color	android:textColor	setTextColor getTextColors	inherits from AppCompatRadioButton
Typography	android:textAppearance	setTextAppearance	inherits from AppCompatRadioButton

Radio button states

Radio buttons can be selected or unselected. Radio buttons have enabled, disabled, hover, focused, and pressed states.

Styles

Element	Style
Default style	Widget.MaterialComponents.CompoundButton.RadioButton

Default style theme attribute: ?attr/radioButtonStyle

See the full list of styles and attrs.

Theming radio buttons

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

Radio button theming example

API and source code:

• MaterialRadioButton
  • Class definition
  • Class source
• RadioGroup
  • Class definition

The following example shows a radio button with Material Theming.

Implementing radio button theming

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

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

or using default style theme attributes, styles and theme overlays (themes all radio buttons but does not affect other components):

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

<style name="Widget.App.RadioButton" parent="Widget.MaterialComponents.CompoundButton.RadioButton">
    <item name="materialThemeOverlay">@style/ThemeOverlay.App.RadioButton</item>
</style>

<style name="ThemeOverlay.App.RadioButton" parent="">
    <item name="colorOnSurface">@color/shrine_pink_900</item>
    <item name="colorSecondary">@color/shrine_pink_100</item>
</style>

you can also change the radio button colors via the ?attr/buttonTint attribute:

<style name="Widget.App.RadioButton" parent="Widget.MaterialComponents.CompoundButton.RadioButton">
   <item name="buttonTint">@color/button_tint</item>
</style>

and in color/button_tint.xml:

<selector xmlns:android="http://schemas.android.com/apk/res/android">
  <item android:color="@color/shrine_pink_900" android:state_checked="true"/>
  <item android:alpha="0.38" android:color="@color/shrine_pink_100" android:state_enabled="false"/>
  <item android:color="@color/shrine_pink_100"/>
</selector>

or using the styles in the layout (affects only this radio button):

<RadioButton
        ...
    style="@style/Widget.App.RadioButton"
    />