Switch class Null safety

A Material Design switch.

Used to toggle the on/off state of a single setting.

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

If the onChanged callback is null, then the switch will be disabled (it will not respond to input). A disabled switch's thumb and track are rendered in shades of grey by default. The default appearance of a disabled switch can be overridden with inactiveThumbColor and inactiveTrackColor.

Requires one of its ancestors to be a Material widget.

link
This example shows a toggleable Switch. When the thumb slides to the other side of the track, the switch is toggled between on/off.
To create a local project with this code sample, run:
flutter create --sample=material.Switch.1 mysample

link
This example shows how to customize Switch using MaterialStateProperty switch properties.
To create a local project with this code sample, run:
flutter create --sample=material.Switch.2 mysample

See also:

Inheritance

Constructors

Switch({Key? key, required bool value, required ValueChanged<bool>? onChanged, Color? activeColor, Color? activeTrackColor, Color? inactiveThumbColor, Color? inactiveTrackColor, ImageProvider<Object>? activeThumbImage, ImageErrorListener? onActiveThumbImageError, ImageProvider<Object>? inactiveThumbImage, ImageErrorListener? onInactiveThumbImageError, MaterialStateProperty<Color?>? thumbColor, MaterialStateProperty<Color?>? trackColor, MaterialTapTargetSize? materialTapTargetSize, DragStartBehavior dragStartBehavior = DragStartBehavior.start, MouseCursor? mouseCursor, Color? focusColor, Color? hoverColor, MaterialStateProperty<Color?>? overlayColor, double? splashRadius, FocusNode? focusNode, bool autofocus = false})
Creates a Material Design switch.
const
Switch.adaptive({Key? key, required bool value, required ValueChanged<bool>? onChanged, Color? activeColor, Color? activeTrackColor, Color? inactiveThumbColor, Color? inactiveTrackColor, ImageProvider<Object>? activeThumbImage, ImageErrorListener? onActiveThumbImageError, ImageProvider<Object>? inactiveThumbImage, ImageErrorListener? onInactiveThumbImageError, MaterialTapTargetSize? materialTapTargetSize, MaterialStateProperty<Color?>? thumbColor, MaterialStateProperty<Color?>? trackColor, DragStartBehavior dragStartBehavior = DragStartBehavior.start, MouseCursor? mouseCursor, Color? focusColor, Color? hoverColor, MaterialStateProperty<Color?>? overlayColor, double? splashRadius, FocusNode? focusNode, bool autofocus = false})
Creates an adaptive Switch 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 switch is on.
final
activeThumbImage → ImageProvider<Object>?
An image to use on the thumb of this switch when the switch is on.
final
activeTrackColor → Color?
The color to use on the track when this switch is on.
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
dragStartBehavior → DragStartBehavior
Determines the way that drag start behavior is handled.
final
focusColor → Color?
The color for the button'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">@nonVirtualread-onlyinherited
hoverColor → Color?
The color for the button's Material when a pointer is hovering over it.
final
inactiveThumbColor → Color?
The color to use on the thumb when this switch is off.
final
inactiveThumbImage → ImageProvider<Object>?
An image to use on the thumb of this switch when the switch is off.
final
inactiveTrackColor → Color?
The color to use on the track when this switch is off.
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
onActiveThumbImageError → ImageErrorListener?
An optional error callback for errors emitted when loading activeThumbImage.
final
onChanged → ValueChanged<bool>?
Called when the user toggles the switch on or off.
final
onInactiveThumbImageError → ImageErrorListener?
An optional error callback for errors emitted when loading inactiveThumbImage.
final
overlayColor → MaterialStateProperty<Color?>?
The color for the switch's Material.
final
runtimeType → Type
A representation of the runtime type of the object.
read-onlyinherited
splashRadius → double?
The splash radius of the circular Material ink response.
final
thumbColor → MaterialStateProperty<Color?>?
The color of this Switch's thumb.
final
trackColor → MaterialStateProperty<Color?>?
The color of this Switch's track.
final
value → bool
Whether this switch is on or off.
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.
protected">@protectedinherited
debugFillProperties(DiagnosticPropertiesBuilder properties) → void
Add additional properties associated with the node.
override
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">@nonVirtualinherited