A Material Design radio button.
This widget builds a RawRadio with a material UI.
Used to select between a number of mutually exclusive values. When one radio
button in a group is selected, the other radio buttons in the group cease to
be selected. The values are of type T, the type parameter of the Radio
class. Enums are commonly used for this purpose.
This widget typically has a RadioGroup ancestor, which takes in a RadioGroup.groupValue, and the Radio under it with matching value will be selected.
Here is an example of Radio widgets wrapped in ListTiles, which is similar to what you could get with the RadioListTile widget.
The currently selected character is passed into RadioGroup.groupValue,
which is maintained by the example's State. In this case, the first Radio
will start off selected because _character is initialized to
SingingCharacter.lafayette.
If the second radio button is pressed, the example's state is updated
with setState, updating _character to SingingCharacter.jefferson.
This causes the buttons to rebuild with the updated RadioGroup.groupValue, and
therefore the selection of the second button.
Requires one of its ancestors to be a Material widget.
To create a local project with this code sample, run:
flutter create --sample=material.Radio.1 mysample
Here is an example of how the you can override the default theme of a Radio with WidgetStateProperty.
In this example:
To create a local project with this code sample, run:
flutter create --sample=material.Radio.2 mysample
See also:
- RadioListTile, which combines this widget with a ListTile so that you can give the radio button a label.
- Slider, for selecting a value in a range.
- Checkbox and Switch, for toggling a particular value on or off.
- material.io/design/components/selection-controls.html#radio-buttons
- Inheritance
Constructors
-
Radio({Key? key, required T value, @Deprecated('Use a RadioGroup ancestor to manage group value instead. ' 'This feature was deprecated after v3.32.0-0.0.pre.') T? groupValue, @Deprecated('Use RadioGroup to handle value change instead. ' 'This feature was deprecated after v3.32.0-0.0.pre.') ValueChanged<
T?> ? onChanged, MouseCursor? mouseCursor, bool toggleable = false, Color? activeColor, WidgetStateProperty<Color?> ? fillColor, Color? focusColor, Color? hoverColor, WidgetStateProperty<Color?> ? overlayColor, double? splashRadius, MaterialTapTargetSize? materialTapTargetSize, VisualDensity? visualDensity, FocusNode? focusNode, bool autofocus = false, bool? enabled, RadioGroupRegistry<T> ? groupRegistry, WidgetStateProperty<Color?> ? backgroundColor, BorderSide? side, WidgetStateProperty<double?> ? innerRadius}) -
Creates a Material Design radio button.
const
-
Radio.adaptive({Key? key, required T value, @Deprecated('Use a RadioGroup ancestor to manage group value instead. ' 'This feature was deprecated after v3.32.0-0.0.pre.') T? groupValue, @Deprecated('Use RadioGroup to handle value change instead. ' 'This feature was deprecated after v3.32.0-0.0.pre.') ValueChanged<
T?> ? onChanged, MouseCursor? mouseCursor, bool toggleable = false, Color? activeColor, WidgetStateProperty<Color?> ? fillColor, Color? focusColor, Color? hoverColor, WidgetStateProperty<Color?> ? overlayColor, double? splashRadius, MaterialTapTargetSize? materialTapTargetSize, VisualDensity? visualDensity, FocusNode? focusNode, bool autofocus = false, bool useCupertinoCheckmarkStyle = false, bool? enabled, RadioGroupRegistry<T> ? groupRegistry, WidgetStateProperty<Color?> ? backgroundColor, BorderSide? side, WidgetStateProperty<double?> ? innerRadius}) -
Creates an adaptive Radio based on whether the target platform is iOS
or macOS, following Material design's
Cross-platform guidelines.
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
-
backgroundColor
→ WidgetStateProperty<
Color?> ? -
The color of the background of the radio button, in all WidgetStates.
final
- enabled → bool?
-
Whether this widget is interactive.
final
-
fillColor
→ WidgetStateProperty<
Color?> ? -
The color that fills the radio button, in all WidgetStates.
final
- focusColor → Color?
-
The color for the radio's Material when it has the input focus.
final
- focusNode → FocusNode?
-
An optional focus node to use as the focus node for this widget.
final
-
groupRegistry
→ RadioGroupRegistry<
T> ? -
The registry this radio registers to.
final
- groupValue → T?
-
The currently selected value for a group of radio buttons.
final
- hashCode → int
-
The hash code for this object.
no setterinherited
- hoverColor → Color?
-
The color for the radio's Material when a pointer is hovering over it.
final
-
innerRadius
→ WidgetStateProperty<
double?> ? -
The radius of the inner circle of the radio button, in all WidgetStates.
final
- key → Key?
-
Controls how one widget replaces another widget in the tree.
finalinherited
- materialTapTargetSize → MaterialTapTargetSize?
-
Configures the minimum size of the tap target.
final
- mouseCursor → MouseCursor?
-
The cursor for a mouse pointer when it enters or is hovering over the
widget.
final
-
onChanged
→ ValueChanged<
T?> ? -
Called when the user selects this radio button.
final
-
overlayColor
→ WidgetStateProperty<
Color?> ? -
The color for the radio's Material.
final
- runtimeType → Type
-
A representation of the runtime type of the object.
no setterinherited
- side → BorderSide?
-
The side for the circular border of the radio button, in all
WidgetStates.
final
- splashRadius → double?
-
The splash radius of the circular Material ink response.
final
- toggleable → bool
-
Set to true if this radio button is allowed to be returned to an
indeterminate state by selecting it again when selected.
final
- useCupertinoCheckmarkStyle → bool
-
Controls whether the checkmark style is used in an iOS-style radio.
final
- value → T
-
The value represented by this radio button.
final
- visualDensity → VisualDensity?
-
Defines how compact the radio's layout will be.
final
Methods
-
createElement(
) → StatefulElement -
Creates a StatefulElement to manage this widget's location in the tree.
inherited
-
createState(
) → State< Radio< T> > -
Creates the mutable state for this widget at a given location in the tree.
override
-
debugDescribeChildren(
) → List< DiagnosticsNode> -
Returns a list of DiagnosticsNode objects describing this node's
children.
inherited
-
debugFillProperties(
DiagnosticPropertiesBuilder properties) → void -
Add additional properties associated with the node.
inherited
-
noSuchMethod(
Invocation invocation) → dynamic -
Invoked when a nonexistent 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, int wrapWidth = 65}) → 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.
inherited