Radio< T> class
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:
- 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.google.com/components/selection-controls.html#selection-controls-radio-button
- Inheritance
Constructors
-
Radio({Key key, @required T value, @required T groupValue, @required ValueChanged<
T> onChanged, Color activeColor, MaterialTapTargetSize materialTapTargetSize }) -
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
- materialTapTargetSize → MaterialTapTargetSize
-
Configures the minimum size of the tap target. [...]
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. [...]
override
-
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 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 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 ==(
dynamic other) → bool -
The equality operator. [...]
inherited