CupertinoSegmentedControl<T extends Object> class Null safety

An iOS-style segmented control.

Displays the widgets provided in the Map of children in a horizontal list. Used to select between a number of mutually exclusive options. When one option in the segmented control is selected, the other options in the segmented control cease to be selected.

A segmented control can feature any Widget as one of the values in its Map of children. The type T is the type of the keys used to identify each widget and determine which widget is selected. As required by the Map class, keys must be of consistent types and must be comparable. The ordering of the keys will determine the order of the widgets in the segmented control.

When the state of the segmented control changes, the widget calls the onValueChanged callback. The map key associated with the newly selected widget is returned in the onValueChanged callback. Typically, widgets that use a segmented control will listen for the onValueChanged callback and rebuild the segmented control with a new groupValue to update which option is currently selected.

The children will be displayed in the order of the keys in the Map. The height of the segmented control is determined by the height of the tallest widget provided as a value in the Map of children. The width of each child in the segmented control will be equal to the width of widest child, unless the combined width of the children is wider than the available horizontal space. In this case, the available horizontal space is divided by the number of provided children to determine the width of each widget. The selection area for each of the widgets in the Map of children will then be expanded to fill the calculated space, so each widget will appear to have the same dimensions.

A segmented control may optionally be created with custom colors. The unselectedColor, selectedColor, borderColor, and pressedColor arguments can be used to override the segmented control's colors from CupertinoTheme defaults.

link
This example shows a CupertinoSegmentedControl with an enum type.

The callback provided to onValueChanged should update the state of the parent StatefulWidget using the State.setState method, so that the parent gets rebuilt; for example:

To create a local project with this code sample, run:
flutter create --sample=cupertino.CupertinoSegmentedControl.1 mysample

See also:

Inheritance

Constructors

CupertinoSegmentedControl({Key? key, required Map<T, Widget> children, required ValueChanged<T> onValueChanged, T? groupValue, Color? unselectedColor, Color? selectedColor, Color? borderColor, Color? pressedColor, EdgeInsetsGeometry? padding})
Creates an iOS-style segmented control bar.

Properties

borderColor → Color?
The color used as the border around each widget.
final
children → Map<T, Widget>
The identifying keys and corresponding widget values in the segmented control.
final
groupValue → T?
The identifier of the widget that is currently selected.
final
hashCode → int
The hash code for this object.
nonVirtual">@nonVirtualread-onlyinherited
key → Key?
Controls how one widget replaces another widget in the tree.
finalinherited
onValueChanged → ValueChanged<T>
The callback that is called when a new option is tapped.
final
padding → EdgeInsetsGeometry?
The CupertinoSegmentedControl will be placed inside this padding.
final
pressedColor → Color?
The color used to fill the background of the widget the user is temporarily interacting with through a long press or drag.
final
runtimeType → Type
A representation of the runtime type of the object.
read-onlyinherited
selectedColor → Color?
The color used to fill the background of the selected widget and as the text color of unselected widgets.
final
unselectedColor → Color?
The color used to fill the backgrounds of unselected widgets and as the text color of the selected widget.
final

Methods

createElement() → StatefulElement
Creates a StatefulElement to manage this widget's location in the tree.
inherited
createState() → State<CupertinoSegmentedControl<T>>
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">@protectedinherited
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">@nonVirtualinherited