TransitionPlugin class abstract

The plugin contract every transition must implement.

Add any new visual effect to the framework by creating a class that extends TransitionPlugin — zero changes to the core.

class GlowTransitionPlugin extends TransitionPlugin {
  @override String get id => 'glow';
  @override List<AnimatableProperty> get affectedProperties => [...];
  @override bool get isExpensive => true;
  @override Widget build({required animation, required child,
                          Map<String, Object?> params = const {}}) { ... }
}

Why extends instead of implements?

Dart does not allow abstract method declarations to carry default parameter values — they must live on a concrete declaration. By making build() a concrete method that throws UnimplementedError, subclasses inherit the default params = const {} from the base class, so call sites that omit params: always compile against the base-class signature.

Implementers

• BlurTransitionPlugin
• FadeTransitionPlugin
• Flip3DTransitionPlugin
• LiquidTransitionPlugin
• MorphTransitionPlugin
• ParallaxTransitionPlugin
• RippleTransitionPlugin
• RotateTransitionPlugin
• ScaleTransitionPlugin
• ShimmerTransitionPlugin
• SlideTransitionPlugin
• SpringTransitionPlugin

Constructors

TransitionPlugin()

const

Properties

affectedProperties → List<AnimatableProperty>

All widget properties this transition modifies. Used by FrameBudgeter to decide whether to skip expensive effects.

no setter

description → String

Human-readable description of this transition (optional, for tooling).

no setter

hashCode → int

The hash code for this object.

no setter, inherited

id → String

Unique identifier used to look up this plugin in TransitionRegistry.

no setter

isExpensive → bool

True when this effect uses expensive GPU operations (blur, shader, clip). The FrameBudgeter will disable expensive plugins under FPS threshold.

no setter

runtimeType → Type

A representation of the runtime type of the object.

no setter, inherited

Methods

build({required Animation<double> animation, required Widget child, Map<String, Object?> params = const {}}) → Widget

Builds the animated widget for the forward direction.

buildCurved({required Animation<double> animation, required Curve curve, required Widget child, Map<String, Object?> params = const {}}) → Widget

Helper — wraps build with a CurvedAnimation.

buildReverse({required Animation<double> animation, required Widget child, Map<String, Object?> params = const {}}) → Widget

Builds the animated widget for the reverse direction.

noSuchMethod(Invocation invocation) → dynamic

Invoked when a nonexistent method or property is accessed.

inherited

toString() → String

A string representation of this object.

override

Operators

operator ==(Object other) → bool

The equality operator.

inherited