Stepper class

A numeric stepper: [ − 42 + ]. When focused, Up / Down (or + / −) change the value by step, PageUp / PageDown by largeStep, and Home / End jump to min / max. Typing digits enters a value directly; Enter or leaving the field commits it, and Escape cancels. Clicking the − or + half also nudges the value, so pointer users get the same affordance.

Controlled — hold the value yourself and update it from onChanged. Passing null for onChanged disables the stepper.

Stepper(
  value: count,
  min: 0,
  max: 100,
  onChanged: (v) => setState(() => count = v),
)

Inheritance

• Object
• Widget
• StatefulWidget
• Stepper

Available extensions

• AnimateExtension

Constructors

Stepper({Key? key, required num value, required void onChanged(num value)?, num? min, num? max, num step = 1, num largeStep = 10, String formatter(num value)?, String? label, FocusNode? focusNode, bool autofocus = false, CellStyle? style})

const

Properties

autofocus → bool

Whether the stepper should request focus when mounted.

final

focusNode → FocusNode?

Focus node used for keyboard and text-input interaction.

final

formatter → String Function(num value)?

Renders the value into the display string. Defaults to v.toInt().toString() for whole values and a one-decimal form otherwise — mirrors what BarChart uses, so the look matches.

final

hashCode → int

The hash code for this object.

no setter, inherited

key → Key?

final, inherited

label → String?

Optional label shown to the left of the stepper.

final

largeStep → num

Amount added/subtracted on PageUp / PageDown. Should be ≥ step.

final

max → num?

Upper bound. null means unbounded above.

final

min → num?

Lower bound. null means unbounded below.

final

onChanged → void Function(num value)?

Called with the new value when the user nudges it.

final

runtimeType → Type

A representation of the runtime type of the object.

no setter, inherited

step → num

Amount added/subtracted on Up / Down / + / − or a click on a button.

final

style → CellStyle?

Base styling for the value and frame, plus optional hover, focus, disabled, and invalid state entries from CellStyle.interactive.

final

value → num

Current value.

final

Methods

animate({Duration? duration, Curve? curve, Object? trigger, bool repeat = false}) → Animate

Available on Widget, provided by the AnimateExtension extension

Starts an Animate chain over this widget. duration / curve apply to the whole chain. With no trigger it plays on mount; with a non-null trigger it rests on mount and replays whenever the token changes.

createElement() → StatefulElement

Creates the Element that will mount this widget into the tree.

inherited

createState() → State<Stepper>

Creates the mutable state for this widget at the current location in the tree. Called exactly once per StatefulElement instance.

override

noSuchMethod(Invocation invocation) → dynamic

Invoked when a nonexistent method or property is accessed.

inherited

toString() → String

A string representation of this object.

inherited

Operators

operator ==(Object other) → bool

The equality operator.

inherited