A material design radio button.

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.

The radio button itself does not maintain any state. Instead, when the state of the radio button changes, the widget calls the onChanged callback. Most widget that use a radio button will listen for the onChanged callback and rebuild the radio button with a new groupValue to update the visual appearance of the radio button.

Requires one of its ancestors to be a Material widget.

See also:

Inheritance

Constructors

Radio({Key key, @required T value, @required T groupValue, @required ValueChanged<T> onChanged, Color activeColor })
Creates a material design radio button. [...]
const

Properties

activeColor Color
The color to use when this radio button is selected. [...]
final
groupValue → T
The currently selected value for this group of radio buttons. [...]
final
onChanged ValueChanged<T>
Called when the user selects this radio button. [...]
final
value → T
The value represented by this radio button.
final
hashCode int
The hash code for this object. [...]
read-only, inherited
key Key
Controls how one widget replaces another widget in the tree. [...]
final, inherited
runtimeType Type
A representation of the runtime type of the object.
read-only, inherited

Methods

createState() → _RadioState<T>
Creates the mutable state for this widget at a given location in the tree. [...]
createElement() StatefulElement
Creates a StatefulElement 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, inherited
debugFillProperties(DiagnosticPropertiesBuilder description) → 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 toStringDeep. [...]
inherited
toString({DiagnosticLevel minLevel: DiagnosticLevel.debug }) String
Returns 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 ==(other) bool
The equality operator. [...]
inherited