SwapEffect class

An effect that swaps out the incoming child for a new child at a particular point in time. This includes all preceding effects. It uses a builder so that the effect can be reused, but note that the builder is only called once when the effect initially builds.

For example, this would fade out foo, swap it for Bar() (including discarding the fadeOut effect) and apply a fade in effect.

foo.animate()
  .fadeOut(duration: 500.ms)
  .swap( // inherits duration from fadeOut
    builder: (_, __) => Bar().animate().fadeIn(),
  )

It also includes the original child of the animation as a parameter of the builder. For example, normally fading out and then back in will not work as expected because both effects are active (ie. the 0 opacity from fading out is still applied), but you can work around this by beginning a new animation with the original child:

foo.animate()
  .fadeOut(duration: 500.ms)
  .swap( // inherits duration from fadeOut
    builder: (_, originalChild) => originalChild.animate().fadeIn(),
  )

Note that the builder is returning a new Animate instance with its own AnimationController. So, for example, repeating the first animation (the fade out) via its controller will not affect the second animation (fade in).

Inheritance
Annotations

Constructors

SwapEffect({Duration? delay, Duration? duration, Curve? curve, required Widget builder(BuildContext, Widget)})
const

Properties

begin → void
The begin value for the effect. If null, effects should use a reasonable default value when appropriate.
finalinherited
builder → Widget Function(BuildContext, Widget)
final
curve → Curve?
The specified easing curve for the effect. If null, will inherit the curve from the previous effect, or use Animate.defaultCurve if this is the first effect.
finalinherited
delay → Duration?
The specified delay for the effect. If null, will inherit the delay from the previous effect, or use Duration.zero if this is the first effect.
finalinherited
duration → Duration?
The specified duration for the effect. If null, will inherit the duration from the previous effect, or use Animate.defaultDuration if this is the first effect.
finalinherited
end → void
The end value for the effect. If null, effects should use a reasonable default value when appropriate.
finalinherited
hashCode → int
The hash code for this object.
no setterinherited
runtimeType → Type
A representation of the runtime type of the object.
no setterinherited

Methods

build(BuildContext context, Widget child, AnimationController controller, EffectEntry entry) → Widget
Builds the widgets that implement the effect on the target child, based on the provided AnimationController and EffectEntry.
override
buildAnimation(AnimationController controller, EffectEntry entry) → Animation<void>
Returns an animation based on the controller, entry, and begin/end values.
inherited
getBeginRatio(AnimationController controller, EffectEntry entry) → double
Returns a ratio corresponding to the beginning of the specified entry.
inherited
getEndRatio(AnimationController controller, EffectEntry entry) → double
Returns a ratio corresponding to the end of the specified entry.
inherited
getOptimizedBuilder<U>({required ValueListenable<U> animation, Widget? child, required TransitionBuilder builder}) → AnimatedBuilder
Returns an optimized AnimatedBuilder that doesn't rebuild if the value hasn't changed.
inherited
getToggleBuilder({required ValueListenable<double> animation, required Widget child, required bool toggle(), required ToggleEffectBuilder builder}) → AnimatedBuilder
Returns an AnimatedBuilder that rebuilds when the boolean value returned by the toggle function changes.
inherited
isAnimationActive(Animation animation) → bool
Check if the animation is currently running / active.
inherited
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