Switch class
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.
Material Design 3 provides the option to add icons on the thumb of the Switch. If ThemeData.useMaterial3 is set to true, users can use Switch.thumbIcon to add optional Icons based on the different MaterialStates of the Switch.
To create a local project with this code sample, run:
flutter create --sample=material.Switch.1 mysample
To create a local project with this code sample, run:
flutter create --sample=material.Switch.2 mysample
To create a local project with this code sample, run:
flutter create --sample=material.Switch.3 mysample
To create a local project with this code sample, run:
flutter create --sample=material.Switch.4 mysample
See also:
- SwitchListTile, which combines this widget with a ListTile so that you can give the switch a label.
- Checkbox, another widget with similar semantics.
- Radio, for selecting among a set of explicit values.
- Slider, for selecting a value in a range.
- MaterialStateProperty, an interface for objects that "resolve" to different values depending on a widget's material state.
- material.io/design/components/selection-controls.html#switches
- 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, MaterialStateProperty<Color?> ? trackOutlineColor, MaterialStateProperty<double?> ? trackOutlineWidth, MaterialStateProperty<Icon?> ? thumbIcon, MaterialTapTargetSize? materialTapTargetSize, DragStartBehavior dragStartBehavior = DragStartBehavior.start, MouseCursor? mouseCursor, Color? focusColor, Color? hoverColor, MaterialStateProperty<Color?> ? overlayColor, double? splashRadius, FocusNode? focusNode, ValueChanged<bool> ? onFocusChange, 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, MaterialStateProperty<Color?> ? trackOutlineColor, MaterialStateProperty<double?> ? trackOutlineWidth, MaterialStateProperty<Icon?> ? thumbIcon, DragStartBehavior dragStartBehavior = DragStartBehavior.start, MouseCursor? mouseCursor, Color? focusColor, Color? hoverColor, MaterialStateProperty<Color?> ? overlayColor, double? splashRadius, FocusNode? focusNode, ValueChanged<bool> ? onFocusChange, bool autofocus = false, bool? applyCupertinoTheme}) -
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
- applyCupertinoTheme → bool?
-
Whether to apply the ambient CupertinoThemeData.
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.
no setterinherited
- 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
-
onFocusChange
→ ValueChanged<
bool> ? -
Handler called when the focus changes.
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.
no setterinherited
- splashRadius → double?
-
The splash radius of the circular Material ink response.
final
-
thumbColor
→ MaterialStateProperty<
Color?> ? -
The color of this Switch's thumb.
final
-
thumbIcon
→ MaterialStateProperty<
Icon?> ? -
The icon to use on the thumb of this switch
final
-
trackColor
→ MaterialStateProperty<
Color?> ? -
The color of this Switch's track.
final
-
trackOutlineColor
→ MaterialStateProperty<
Color?> ? -
The outline color of this Switch's track.
final
-
trackOutlineWidth
→ MaterialStateProperty<
double?> ? -
The outline width 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.
inherited
-
debugFillProperties(
DiagnosticPropertiesBuilder properties) → void -
Add additional properties associated with the node.
override
-
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}) → 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