FossCheckbox class Inputs

See the checkbox documentation ↗ or try it live in the playground ↗.

A checkbox: an independent on / off toggle that can also show an indeterminate state.

value is tristate: true checked, false unchecked, null indeterminate (the minus glyph). A tap reports the new definite state through onChanged: unchecked and indeterminate go to true, checked goes to false. The checkbox never produces null itself; set value to null to drive the indeterminate state. onChanged: null (or enabled: false) disables it.

Renders a square box with an optional label and description. A non-null errorText marks it invalid and shows a caption below. Colors, type, and spacing come from context.fossTheme; pass a FossCheckboxStyle to style for a one-off.

For a multi-select set of options, see FossCheckboxGroup.

Customize globally by passing your own FossThemeData, or per instance through the widget's style object. There are no per-instance token props: to change color, radius, or spacing, change the theme.

See also FossCheckboxGroup for a multi-select set, and FossRadio or FossSwitch for related toggles.

FossCheckbox(
  value: accepted,
  label: 'Accept terms and conditions',
  onChanged: (checked) => setState(() => accepted = checked),
);

Inheritance

• Object
• DiagnosticableTree
• Widget
• StatelessWidget
• FossCheckbox

Constructors

FossCheckbox({bool? value = false, ValueChanged<bool>? onChanged, String? label, String? description, String? errorText, bool enabled = true, FossCheckboxStyle? style, Key? key})

const

Properties

description → String?

Optional secondary line below the label.

final

enabled → bool

Whether the checkbox accepts input. Disabled when false or when onChanged is null.

final

errorText → String?

Error caption below the control. A non-null value marks it invalid.

final

hashCode → int

The hash code for this object.

no setter, inherited

key → Key?

Controls how one widget replaces another widget in the tree.

final, inherited

label → String?

Optional title beside the box.

final

onChanged → ValueChanged<bool>?

Called with the new definite state on a tap. Null disables the checkbox.

final

runtimeType → Type

A representation of the runtime type of the object.

no setter, inherited

style → FossCheckboxStyle?

Per-instance overrides layered on the theme-resolved style.

final

value → bool?

The checked state: true, false, or null for indeterminate.

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.

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