AnimatedBuilder class

A general-purpose widget that rebuilds whenever a Listenable notifies.

AnimatedBuilder is the primary way to build widgets that depend on an Animation (or any Listenable). It takes an animation and a builder callback, and rebuilds whenever the animation notifies its listeners.

The optional child parameter allows you to cache a subtree that does not depend on the animation, avoiding unnecessary rebuilds.

AnimatedBuilder(
  animation: controller,
  builder: (context, child) {
    return Container(
      width: controller.value * 100,
      child: child,
    );
  },
  child: Text('Hello'),
)
Inheritance

Constructors

AnimatedBuilder({required Listenable animation, required Widget builder(BuildContext context, Widget? child), Widget? child, Key? key})
Creates a widget that rebuilds when animation notifies.

Properties

animation → Listenable
The Listenable to which this widget is listening.
final
builder → Widget Function(BuildContext context, Widget? child)
Called every time the animation notifies.
final
child → Widget?
An optional child widget that does not depend on the animation.
final
children → List<Widget>
Child widgets that receive forwarded messages.
no setterinherited
debugRenderObjectPassthrough → bool
Whether this widget is intentionally transparent to render-object layouts.
no setterinherited
focusable → bool
Whether this widget can receive keyboard focus.
no setterinherited
hashCode → int
The hash code for this object.
no setterinherited
id → String
Unique identifier for this widget.
no setterinherited
key → Key?
Key for preserving widget identity.
finalinherited
runtimeType → Type
A representation of the runtime type of the object.
no setterinherited
theme → Theme
Access the current theme.
no setterinherited

Methods

buildCachedView<T>(T builder(), Object? cacheKey) → T
Returns a cached view if the cache key matches.
inherited
createState() → State<AnimatedBuilder>
Creates the mutable State associated with this widget.
override
handleInit() → Cmd?
Override this instead of init for widget-specific initialization.
inherited
handleIntercept(Msg msg) → (Widget, Cmd?)
Override this to handle messages before they reach children.
inherited
handleUpdate(Msg msg) → (Widget, Cmd?)
Override this to handle messages specific to this widget.
inherited
init() → Cmd?
Called once when the widget is first mounted.
inherited
invalidateCachedView() → void
Clears any cached view for this widget.
inherited
noSuchMethod(Invocation invocation) → dynamic
Invoked when a nonexistent method or property is accessed.
inherited
toString() → String
A string representation of this object.
inherited
update(Msg msg) → (Model, Cmd?)
Handles messages by forwarding to children then calling handleUpdate.
inherited
view() → Object
Renders the widget to a string or View.
inherited

Operators

operator ==(Object other) → bool
The equality operator.
inherited