What is the definition of explicit animations and what is their application?

Explicit animations in Flutter are animations that the developer fully controls: from creating an animation controller (AnimationController), setting the animation curve (Curve), to managing animation states (start, stop, repeat, etc.). They allow creating complex and custom animation effects.

Using explicit animations is relevant when precise control over animation behavior is needed, such as when creating interactive transitions, UI animations, or complex visual effects.

Example of an explicit animation in Flutter:

class MyAnimatedWidget extends StatefulWidget {
  @override
  _MyAnimatedWidgetState createState() => _MyAnimatedWidgetState();
}

class _MyAnimatedWidgetState extends State<MyAnimatedWidget> with SingleTickerProviderStateMixin {
  late AnimationController _controller;
  late Animation<double> _animation;

  @override
  void initState() {
    super.initState();
    _controller = AnimationController(
      duration: const Duration(seconds: 2),
      vsync: this,
    );
    _animation = CurvedAnimation(parent: _controller, curve: Curves.easeIn);
    _controller.forward();
  }

  @override
  void dispose() {
    _controller.dispose();
    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    return FadeTransition(
      opacity: _animation,
      child: const Text('Explicit animation'),
    );
  }
}