Checkbox class Null safety

A material design checkbox.

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

The checkbox can optionally display three values - true, false, and null - if tristate is true. When value is null a dash is displayed. By default tristate is false and the checkbox's value must be true or false.

Requires one of its ancestors to be a Material widget.

See also:

Inheritance

Constructors

Checkbox({Key? key, required bool? value, bool tristate: false, required ValueChanged<bool?>? onChanged, MouseCursor? mouseCursor, Color? activeColor, MaterialStateProperty<Color?>? fillColor, Color? checkColor, Color? focusColor, Color? hoverColor, MaterialStateProperty<Color?>? overlayColor, double? splashRadius, MaterialTapTargetSize? materialTapTargetSize, VisualDensity? visualDensity, FocusNode? focusNode, bool autofocus: false})
Creates a material design checkbox. [...]
const

Properties

activeColor Color?
The color to use when this checkbox is checked. [...]
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
checkColor Color?
The color to use for the check icon when this checkbox is checked. [...]
final
fillColor MaterialStateProperty<Color?>?
The color that fills the checkbox, in all MaterialStates. [...]
final
focusColor Color?
The color for the checkbox'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
hashCode int
The hash code for this object. [...]
@nonVirtual, read-only, inherited
hoverColor Color?
The color for the checkbox's Material when a pointer is hovering over it. [...]
final
key Key?
Controls how one widget replaces another widget in the tree. [...]
final, inherited
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<bool?>?
Called when the value of the checkbox should change. [...]
final
overlayColor MaterialStateProperty<Color?>?
The color for the checkbox's Material. [...]
final
runtimeType Type
A representation of the runtime type of the object.
read-only, inherited
splashRadius double?
The splash radius of the circular Material ink response. [...]
final
tristate bool
If true the checkbox's value can be true, false, or null. [...]
final
value bool?
Whether this checkbox is checked. [...]
final
visualDensity VisualDensity?
Defines how compact the checkbox's layout will be. [...]
final

Methods

createElement() StatefulElement
Creates a StatefulElement to manage this widget's location in the tree. [...]
inherited
createState() → _CheckboxState
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. [...]
@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 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, inherited

Constants

width → const double
The width of a checkbox widget.
18.0