RadioListTile<T> class Null safety

A ListTile with a Radio. In other words, a radio button with a label.

The entire list tile is interactive: tapping anywhere in the tile selects the radio button.

The value, groupValue, onChanged, and activeColor properties of this widget are identical to the similarly-named properties on the Radio widget. The type parameter T serves the same purpose as that of the Radio class' type parameter.

The title, subtitle, isThreeLine, and dense properties are like those of the same name on ListTile.

The selected property on this widget is similar to the ListTile.selected property. This tile's activeColor is used for the selected item's text color, or the theme's ThemeData.toggleableActiveColor if activeColor is null.

This widget does not coordinate the selected state and the checked state; to have the list tile appear selected when the radio button is the selected radio button, set selected to true when value matches groupValue.

The radio button is shown on the left by default in left-to-right languages (i.e. the leading edge). This can be changed using controlAffinity. The secondary widget is placed on the opposite side. This maps to the ListTile.leading and ListTile.trailing properties of ListTile.

This widget requires a Material widget ancestor in the tree to paint itself on, which is typically provided by the app's Scaffold. The tileColor, and selectedTileColor are not painted by the RadioListTile itself but by the Material widget ancestor. In this case, one can wrap a Material widget around the RadioListTile, e.g.:

Container(
  color: Colors.green,
  child: Material(
    child: RadioListTile<Meridiem>(
      tileColor: Colors.red,
      title: const Text('AM'),
      groupValue: Meridiem.am,
      value: Meridiem.am,
      onChanged:(Meridiem? value) { },
    ),
  ),
)

Performance considerations when wrapping RadioListTile with Material

Wrapping a large number of RadioListTiles individually with Materials is expensive. Consider only wrapping the RadioListTiles that require it or include a common Material ancestor where possible.

To show the RadioListTile as disabled, pass null as the onChanged callback.

This widget shows a pair of radio buttons that control the _character field. The field is of the type SingingCharacter, an enum.

To create a local project with this code sample, run:
flutter create --sample=material.RadioListTile.2 mysample

Semantics in RadioListTile

Since the entirety of the RadioListTile is interactive, it should represent itself as a single interactive entity.

To do so, a RadioListTile widget wraps its children with a MergeSemantics widget. MergeSemantics will attempt to merge its descendant Semantics nodes into one node in the semantics tree. Therefore, RadioListTile will throw an error if any of its children requires its own Semantics node.

For example, you cannot nest a RichText widget as a descendant of RadioListTile. RichText has an embedded gesture recognizer that requires its own Semantics node, which directly conflicts with RadioListTile's desire to merge all its descendants' semantic nodes into one. Therefore, it may be necessary to create a custom radio tile widget to accommodate similar use cases.

Here is an example of a custom labeled radio widget, called LinkedLabelRadio, that includes an interactive RichText widget that handles tap gestures.

To create a local project with this code sample, run:
flutter create --sample=material.RadioListTile.3 mysample

RadioListTile isn't exactly what I want

If the way RadioListTile pads and positions its elements isn't quite what you're looking for, you can create custom labeled radio widgets by combining Radio with other widgets, such as Text, Padding and InkWell.

Here is an example of a custom LabeledRadio widget, but you can easily make your own configurable widget.

To create a local project with this code sample, run:
flutter create --sample=material.RadioListTile.4 mysample

Constructors

RadioListTile({Key? key, required T value, required T? groupValue, required ValueChanged<T?>? onChanged, bool toggleable = false, Color? activeColor, Widget? title, Widget? subtitle, bool isThreeLine = false, bool? dense, Widget? secondary, bool selected = false, ListTileControlAffinity controlAffinity = ListTileControlAffinity.platform, bool autofocus = false, EdgeInsetsGeometry? contentPadding, ShapeBorder? shape, Color? tileColor, Color? selectedTileColor, VisualDensity? visualDensity, FocusNode? focusNode, bool? enableFeedback}): Creates a combination of a list tile and a radio button.
const

Properties

activeColor → Color?: The color to use when this radio button is selected.
final
autofocus → bool: True if this widget will be selected as the initial focus when no other node in its scope is currently focused.
final
checked → bool: Whether this radio button is checked.
read-only
contentPadding → EdgeInsetsGeometry?: Defines the insets surrounding the contents of the tile.
final
controlAffinity → ListTileControlAffinity: Where to place the control relative to the text.
final
dense → bool?: Whether this list tile is part of a vertically dense list.
final
enableFeedback → bool?: Whether detected gestures should provide acoustic and/or haptic feedback.
final
focusNode → FocusNode?: An optional focus node to use as the focus node for this widget.
final
groupValue → T?: The currently selected value for this group of radio buttons.
final
hashCode → int: The hash code for this object.
nonVirtual">@nonVirtualread-onlyinherited
isThreeLine → bool: Whether this list tile is intended to display three lines of text.
final
key → Key?: Controls how one widget replaces another widget in the tree.
finalinherited
onChanged → ValueChanged<T?>?: Called when the user selects this radio button.
final
runtimeType → Type: A representation of the runtime type of the object.
read-onlyinherited
secondary → Widget?: A widget to display on the opposite side of the tile from the radio button.
final
selected → bool: Whether to render icons and text in the activeColor.
final
selectedTileColor → Color?: If non-null, defines the background color when RadioListTile.selected is true.
final
shape → ShapeBorder?: If specified, shape defines the shape of the RadioListTile's InkWell border.
final
subtitle → Widget?: Additional content displayed below the title.
final
tileColor → Color?: If specified, defines the background color for RadioListTile when RadioListTile.selected is false.
final
title → Widget?: The primary content of the list tile.
final
toggleable → bool: Set to true if this radio list tile is allowed to be returned to an indeterminate state by selecting it again when selected.
final
value → T: The value represented by this radio button.
final
visualDensity → VisualDensity?: Defines how compact the list tile's layout will be.
final

Methods

build(BuildContext context) → Widget: Describes the part of the user interface represented by this widget.
override
createElement() → StatelessElement: Creates a StatelessElement to manage this widget's location in the tree.
inherited
debugDescribeChildren() → List<DiagnosticsNode>: Returns a list of DiagnosticsNode objects describing this node's children.
protected">@protectedinherited
debugFillProperties(DiagnosticPropertiesBuilder properties) → void: Add additional properties associated with the node.
inherited
noSuchMethod(Invocation invocation) → dynamic: Invoked when a non-existent method or property is accessed.
inherited
toDiagnosticsNode({String? name, DiagnosticsTreeStyle? style}) → DiagnosticsNode: Returns a debug representation of the object that is used by debugging tools and by DiagnosticsNode.toStringDeep.
inherited
toString({DiagnosticLevel minLevel = DiagnosticLevel.info}) → String: A string representation of this object.
inherited
toStringDeep({String prefixLineOne = '', String? prefixOtherLines, DiagnosticLevel minLevel = DiagnosticLevel.debug}) → String: Returns a string representation of this node and its descendants.
inherited
toStringShallow({String joiner = ', ', DiagnosticLevel minLevel = DiagnosticLevel.debug}) → String: Returns a one-line detailed description of the object.
inherited
toStringShort() → String: A short, textual description of this widget.
inherited

Operators

operator ==(Object other) → bool: The equality operator.
nonVirtual">@nonVirtualinherited

Flutter
material
RadioListTile<T> class