Custom Animations in Flutter

30 March, 2023

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ShowwcaseHQ

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Custom animations in Flutter involve extending the Animation class and defining the visual properties of the animation yourself. This allows you to create custom animations that are not possible with the built-in animation classes.

Here's an example of a custom animation that animates the color of a widget:

import 'package:flutter/animation.dart';

class ColorTweenAnimation extends Animation<Color> {
  ColorTweenAnimation(AnimationController controller) : super(parent: controller);

  Color get begin => Color(0xff000000);
  Color get end => Color(0xffffffff);

  @override
  Color lerp(double t) => Color.lerp(begin, end, t);
}

AnimationController controller;
ColorTweenAnimation animation;

@override
void initState() {
  super.initState();
  controller = AnimationController(duration: Duration(seconds: 1), vsync: this);
  animation = ColorTweenAnimation(controller);
  controller.forward();
}

@override
Widget build(BuildContext context) {
  return AnimatedBuilder(
    animation: animation,
    builder: (context, child) {
      return Container(
        color: animation.value,
        child: child,
      );
    },
    child: Text('Hello World'),
  );
}

In this example, the ColorTweenAnimation class extends the Animation class and defines the begin and end properties, which represent the starting and ending colors of the animation. The lerp method is then used to interpolate between the begin and end colors based on the value of t, which ranges from 0 to 1 over the course of the animation. The AnimatedBuilder widget is then used to display the animation, with the color property of the Container widget set to the value of the animation object.

For more information on custom animations in Flutter, you can check out the following resources:

Flutter documentation on custom animations: https://flutter.dev/docs/development/ui/animations/custom-animations
Flutter Animation Examples sample app: https://github.com/flutter/samples/tree/master/animation_examples

Custom Animations in Flutter

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