ShimmerEffect class

An effect that animates gradient overlay effects (via ShaderMask), such as the shimmer loading effect popularized by facebook.

IMPORTANT: Due to current limitations in Flutter, this effect may cause issues on mobile web when using the HTML renderer. More info can be found here.

NOTE:* By default, this effect adds 0.5px of padding to its target to prevent visual issues, which could effect layout.

By default it animates a simple 50% white gradient clipped by the child content. However it provides a large amount of customization, including changing the gradient angle, colors / stops, and a blendMode.

If colors is not specified then it will use color to build one similar to [transparent, color, transparent].

blendMode specifies how the gradient fill is composited. It defaults to BlendMode.srcATop, which layers the fill over the child, using the child's alpha (ie. the child acts as a mask). Other interesting options include:

BlendMode.srcIn which uses the child as a mask
BlendMode.srcOver layers the gradient fill over the child (no masking)
BlendMode.dstOver layers the gradient fill under the child (no masking)

Note that most blend modes in Flutter do not respect the alpha channel correctly.

padding allows you to expand the area the shimmer applies to. This defaults to 0.5, which helps prevent visual issues with ShaderMask and antialiasing.

Inheritance

Object
Effect<double>
ShimmerEffect

Annotations

@immutable

Constructors

ShimmerEffect({Duration? delay, Duration? duration, Curve? curve, Color? color, List<Color>? colors, List<double>? stops, double? size, double? angle, BlendMode? blendMode, double? padding}): const

Properties

angle → double?: final
begin → double?: The begin value for the effect. If null, effects should use a reasonable default value when appropriate.
finalinherited
blendMode → BlendMode?: final
color → Color?: final
colors → List<Color>?: 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 → double?: 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
padding → double?: final
runtimeType → Type: A representation of the runtime type of the object.
no setterinherited
size → double?: final
stops → List<double>?: final

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<double>: 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

Constants

defaultAngle → const double
defaultBlendMode → const BlendMode
defaultColor → const Color
defaultPadding → const double
defaultSize → const double